*
* rewriteHandler.cpp
* Primary module of query rewriter.
*
* Portions Copyright (c) 2020 Huawei Technologies Co.,Ltd.
* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/gausskernel/optimizer/rewrite/rewriteHandler.cpp
*
* -------------------------------------------------------------------------
*/
#include "postgres.h"
#include "knl/knl_variable.h"
#include "access/sysattr.h"
#include "catalog/gs_matview_dependency.h"
#include "catalog/gs_matview.h"
#include "catalog/pg_type.h"
#include "catalog/pg_class.h"
#include "catalog/pg_proc.h"
#include "catalog/index.h"
#include "catalog/pg_amop.h"
#include "commands/trigger.h"
#include "commands/matview.h"
#include "commands/sequence.h"
#include "commands/tablecmds.h"
#include "executor/executor.h"
#include "foreign/fdwapi.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/clauses.h"
#include "optimizer/prep.h"
#include "parser/analyze.h"
#include "parser/parse_coerce.h"
#include "parser/parsetree.h"
#include "parser/parse_merge.h"
#include "parser/parse_hint.h"
#include "parser/parse_type.h"
#include "rewrite/rewriteDefine.h"
#include "rewrite/rewriteHandler.h"
#include "rewrite/rewriteManip.h"
#include "rewrite/rewriteRlsPolicy.h"
#include "utils/builtins.h"
#include "utils/bytea.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/rel_gs.h"
#include "catalog/pg_constraint.h"
#include "catalog/namespace.h"
#include "client_logic/client_logic.h"
#include "catalog/pg_proc.h"
#include "commands/sqladvisor.h"
#include "miscadmin.h"
#ifdef PGXC
#include "pgxc/locator.h"
#include "pgxc/nodemgr.h"
#include "pgxc/pgxc.h"
#include "nodes/nodes.h"
#include "optimizer/planner.h"
#include "optimizer/var.h"
#include "tcop/tcopprot.h"
#include "tcop/utility.h"
#ifdef ENABLE_MULTIPLE_NODES
#include "tsdb/utils/ts_redis.h"
#endif
#endif
typedef struct rewrite_event {
Oid relation;
CmdType event;
} rewrite_event;
struct SetNewRteIfExistContext {
Query* parsetree;
Oid baseRelid;
int resultRelation;
RangeTblEntry** newRte;
int* newRtIndex;
};
static bool acquireLocksOnSubLinks(Node* node, void* context);
static Query* rewriteRuleAction(
Query* parsetree, Query* rule_action, Node* rule_qual, int rt_index, CmdType event, bool* returning_flag);
static List* adjustJoinTreeList(Query* parsetree, bool removert, int rt_index);
static List *rewriteTargetListIU(List *targetList, CmdType commandType, Relation target_relation, int result_rtindex,
List **attrno_list, bool *hasGenCol);
static TargetEntry* process_matched_tle(TargetEntry* src_tle, TargetEntry* prior_tle, const char* attrName);
static Node* get_assignment_input(Node* node);
static bool rewriteValuesRTE(Query* parsetree, RangeTblEntry* rte, Relation target_relation, List* attrnos,
bool force_nulls);
static void rewriteTargetListUD(Query* parsetree, RangeTblEntry* target_rte, Relation target_relation, int rtindex);
static void rewriteTargetListMutilUD(Query* parsetree, List* rtable, List* resultRelations);
static void rewriteTargetListMutilUpdate(Query* parsetree, List* rtable, List* resultRelations);
static void markQueryForLocking(Query* qry, Node* jtnode, LockClauseStrength strength, LockWaitPolicy waitPolicy, bool pushedDown,
int waitSec);
static List* matchLocks(CmdType event, RuleLock* rulelocks, int varno, Query* parsetree);
static Query* fireRIRrules(Query* parsetree, List* activeRIRs, bool forUpdatePushedDown);
static Bitmapset* adjust_view_column_set(Bitmapset* cols, List* targetlist);
static bool findAttrByName(const char* attributeName, List* tableElts, int maxlen);
static const char* CommonUpdateCheck(Query* viewquery);
static bool SetNewRteIfExist(SetNewRteIfExistContext* context, bool deleteExistingTarget);
static int GetNewResultRelation(Node* node, List* rtable);
extern int ReplaceResultTargetEntry(Query* parsetree, Query* viewquery, List* rtables, int resultRelation);
extern List* RewriteQuery(Query* parsetree, List* rewrite_events);
#ifdef PGXC
typedef struct pull_qual_vars_context {
List* varlist;
int sublevels_up;
int resultRelation;
bool noRepeat;
} pull_qual_vars_context;
static bool pull_qual_vars_walker(Node* node, pull_qual_vars_context* context);
#endif
* AcquireRewriteLocks -
* Acquire suitable locks on all the relations mentioned in the Query.
* These locks will ensure that the relation schemas don't change under us
* while we are rewriting and planning the query.
*
* forUpdatePushedDown indicates that a pushed-down FOR UPDATE/SHARE applies
* to the current subquery, requiring all rels to be opened with RowShareLock.
* This should always be false at the start of the recursion.
*
* Caution: A secondary purpose of this routine is to fix up JOIN RTE references
* to dropped columns (see details below). Because the RTEs are modified in
* place, it is generally appropriate for the caller of this routine to have
* first done a copyObject() to make a writable copy of the querytree in the
* current memory context.
*
* This processing can, and for efficiency's sake should, be skipped when the
* querytree has just been built by the parser: parse analysis already got
* all the same locks we'd get here, and the parser will have omitted dropped
* columns from JOINs to begin with. But we must do this whenever we are
* dealing with a querytree produced earlier than the current command.
*
* About JOINs and dropped columns: although the parser never includes an
* already-dropped column in a JOIN RTE's alias var list, it is possible for
* such a list in a stored rule to include references to dropped columns.
* (If the column is not explicitly referenced anywhere else in the query,
* the dependency mechanism won't consider it used by the rule and so won't
* prevent the column drop.) To support get_rte_attribute_is_dropped(),
* we replace join alias vars that reference dropped columns with NULL Const
* nodes.
*
* (In PostgreSQL 8.0, we did not do this processing but instead had
* get_rte_attribute_is_dropped() recurse to detect dropped columns in joins.
* That approach had horrible performance unfortunately; in particular
* construction of a nested join was O(N^2) in the nesting depth.)
*/
void AcquireRewriteLocks(Query* parsetree, bool forUpdatePushedDown)
{
ListCell* l = NULL;
int rt_index;
* First, process RTEs of the current query level.
*/
rt_index = 0;
foreach (l, parsetree->rtable) {
RangeTblEntry* rte = (RangeTblEntry*)lfirst(l);
Relation rel;
LOCKMODE lockmode;
List* newaliasvars = NIL;
Index curinputvarno;
RangeTblEntry* curinputrte = NULL;
ListCell* ll = NULL;
++rt_index;
switch (rte->rtekind) {
case RTE_RELATION:
* Grab the appropriate lock type for the relation, and do not
* release it until end of transaction. This protects the
* rewriter and planner against schema changes mid-query.
*
* If the relation is the query's result relation, then we
* need RowExclusiveLock. Otherwise, check to see if the
* relation is accessed FOR [KEY] UPDATE/SHARE or not. We can't
* just grab AccessShareLock because then the executor would
* be trying to upgrade the lock, leading to possible
* deadlocks.
*/
if (rt_index == linitial2_int(parsetree->resultRelations))
lockmode = RowExclusiveLock;
else if (forUpdatePushedDown || get_parse_rowmark(parsetree, rt_index) != NULL)
lockmode = RowShareLock;
else
lockmode = AccessShareLock;
rel = heap_open(rte->relid, lockmode);
* While we have the relation open, update the RTE's relkind,
* just in case it changed since this rule was made.
*/
rte->relkind = rel->rd_rel->relkind;
heap_close(rel, NoLock);
break;
case RTE_JOIN:
* Scan the join's alias var list to see if any columns have
* been dropped, and if so replace those Vars with NULL
* Consts.
*
* Since a join has only two inputs, we can expect to see
* multiple references to the same input RTE; optimize away
* multiple fetches.
*/
newaliasvars = NIL;
curinputvarno = 0;
curinputrte = NULL;
foreach (ll, rte->joinaliasvars) {
Var* aliasvar = (Var*)lfirst(ll);
* If the list item isn't a simple Var, then it must
* represent a merged column, ie a USING column, and so it
* couldn't possibly be dropped, since it's referenced in
* the join clause. (Conceivably it could also be a NULL
* constant already? But that's OK too.)
*/
if (IsA(aliasvar, Var)) {
* The elements of an alias list have to refer to
* earlier RTEs of the same rtable, because that's the
* order the planner builds things in. So we already
* processed the referenced RTE, and so it's safe to
* use get_rte_attribute_is_dropped on it. (This might
* not hold after rewriting or planning, but it's OK
* to assume here.)
*/
AssertEreport(aliasvar->varlevelsup == 0, MOD_OPT, "");
if (aliasvar->varno != curinputvarno) {
curinputvarno = aliasvar->varno;
curinputrte = rt_fetch(curinputvarno, parsetree->rtable);
}
if (curinputrte != NULL && get_rte_attribute_is_dropped(curinputrte, aliasvar->varattno)) {
* can't use vartype here, since that might be a
* now-dropped type OID, but it doesn't really
* matter what type the Const claims to be.
*/
aliasvar = (Var*)makeNullConst(INT4OID, -1, InvalidOid);
}
}
newaliasvars = lappend(newaliasvars, aliasvar);
}
rte->joinaliasvars = newaliasvars;
break;
case RTE_SUBQUERY:
* The subquery RTE itself is all right, but we have to
* recurse to process the represented subquery.
*/
AcquireRewriteLocks(
rte->subquery, (forUpdatePushedDown || get_parse_rowmark(parsetree, rt_index) != NULL));
break;
default:
break;
}
}
foreach (l, parsetree->cteList) {
CommonTableExpr* cte = (CommonTableExpr*)lfirst(l);
AcquireRewriteLocks((Query*)cte->ctequery, false);
}
* Recurse into sublink subqueries, too. But we already did the ones in
* the rtable and cteList.
*/
if (parsetree->hasSubLinks)
(void)query_tree_walker(parsetree, (bool (*)())acquireLocksOnSubLinks, NULL, QTW_IGNORE_RC_SUBQUERIES);
}
* Walker to find sublink subqueries for AcquireRewriteLocks
*/
static bool acquireLocksOnSubLinks(Node* node, void* context)
{
if (node == NULL)
return false;
if (IsA(node, SubLink)) {
SubLink* sub = (SubLink*)node;
AcquireRewriteLocks((Query*)sub->subselect, false);
}
* Do NOT recurse into Query nodes, because AcquireRewriteLocks already
* processed subselects of subselects for us.
*/
return expression_tree_walker(node, (bool (*)())acquireLocksOnSubLinks, context);
}
* Walker to pass down views' invoker info to RangeTableEnrty or FuncExpr in a Query
* B format mode use this feature
*/
static bool viewSecurityPassDown(Node* node, void* context)
{
Oid* asUser = (Oid*)context;
if (node == NULL)
return false;
if (IsA(node, RangeTblEntry)) {
RangeTblEntry* rte = (RangeTblEntry*)node;
if (rte->rtekind == RTE_RELATION) {
rte->checkAsUser = *asUser;
AclResult aclresult;
Relation rel = heap_open(rte->relid, NoLock);
Oid namespaceId = RelationGetNamespace(rel);
aclresult = pg_namespace_aclcheck(namespaceId, *asUser, ACL_USAGE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, ACL_KIND_NAMESPACE, get_namespace_name(namespaceId));
heap_close(rel, NoLock);
}
return false;
}
* Do NOT recurse into Query nodes, because fireRIRrules already processed
* subselects of subselects for us.
*/
return expression_tree_walker(node, (bool (*)())viewSecurityPassDown, context);
}
* rewriteRuleAction -
* Rewrite the rule action with appropriate qualifiers (taken from
* the triggering query).
*
* Input arguments:
* parsetree - original query
* rule_action - one action (query) of a rule
* rule_qual - WHERE condition of rule, or NULL if unconditional
* rt_index - RT index of result relation in original query
* event - type of rule event
* Output arguments:
* *returning_flag - set TRUE if we rewrite RETURNING clause in rule_action
* (must be initialized to FALSE)
* Return value:
* rewritten form of rule_action
*/
static Query* rewriteRuleAction(
Query* parsetree, Query* rule_action, Node* rule_qual, int rt_index, CmdType event, bool* returning_flag)
{
int current_varno, new_varno;
int rt_length;
Query* sub_action = NULL;
Query** sub_action_ptr;
* Make modifiable copies of rule action and qual (what we're passed are
* the stored versions in the relcache; don't touch 'em!).
*/
rule_action = (Query*)copyObject(rule_action);
rule_qual = (Node*)copyObject(rule_qual);
* Acquire necessary locks and fix any deleted JOIN RTE entries.
*/
AcquireRewriteLocks(rule_action, false);
(void)acquireLocksOnSubLinks(rule_qual, NULL);
current_varno = rt_index;
rt_length = list_length(parsetree->rtable);
new_varno = PRS2_NEW_VARNO + rt_length;
* Adjust rule action and qual to offset its varnos, so that we can merge
* its rtable with the main parsetree's rtable.
*
* If the rule action is an INSERT...SELECT, the OLD/NEW rtable entries
* will be in the SELECT part, and we have to modify that rather than the
* top-level INSERT (kluge!).
*/
sub_action = getInsertSelectQuery(rule_action, &sub_action_ptr);
OffsetVarNodes((Node*)sub_action, rt_length, 0);
OffsetVarNodes(rule_qual, rt_length, 0);
ChangeVarNodes((Node*)sub_action, PRS2_OLD_VARNO + rt_length, rt_index, 0);
ChangeVarNodes(rule_qual, PRS2_OLD_VARNO + rt_length, rt_index, 0);
* Generate expanded rtable consisting of main parsetree's rtable plus
* rule action's rtable; this becomes the complete rtable for the rule
* action. Some of the entries may be unused after we finish rewriting,
* but we leave them all in place for two reasons:
*
* We'd have a much harder job to adjust the query's varnos if we
* selectively removed RT entries.
*
* If the rule is INSTEAD, then the original query won't be executed at
* all, and so its rtable must be preserved so that the executor will do
* the correct permissions checks on it.
*
* RT entries that are not referenced in the completed jointree will be
* ignored by the planner, so they do not affect query semantics. But any
* permissions checks specified in them will be applied during executor
* startup (see ExecCheckRTEPerms()). This allows us to check that the
* caller has, say, insert-permission on a view, when the view is not
* semantically referenced at all in the resulting query.
*
* When a rule is not INSTEAD, the permissions checks done on its copied
* RT entries will be redundant with those done during execution of the
* original query, but we don't bother to treat that case differently.
*
* NOTE: because planner will destructively alter rtable, we must ensure
* that rule action's rtable is separate and shares no substructure with
* the main rtable. Hence do a deep copy here.
*/
sub_action->rtable = list_concat((List*)copyObject(parsetree->rtable), sub_action->rtable);
* There could have been some SubLinks in parsetree's rtable, in which
* case we'd better mark the sub_action correctly.
*/
if (parsetree->hasSubLinks && !sub_action->hasSubLinks) {
ListCell* lc = NULL;
foreach (lc, parsetree->rtable) {
RangeTblEntry* rte = (RangeTblEntry*)lfirst(lc);
switch (rte->rtekind) {
case RTE_RELATION:
sub_action->hasSubLinks = checkExprHasSubLink((Node*)rte->tablesample)
|| checkExprHasSubLink((Node*)rte->timecapsule);
break;
case RTE_FUNCTION:
sub_action->hasSubLinks = checkExprHasSubLink(rte->funcexpr);
break;
case RTE_VALUES:
sub_action->hasSubLinks = checkExprHasSubLink((Node*)rte->values_lists);
break;
default:
break;
}
if (sub_action->hasSubLinks)
break;
}
}
* Also, we might have absorbed some RTEs with RLS conditions into the
* sub_action. If so, mark it as hasRowSecurity, whether or not those
* RTEs will be referenced after we finish rewriting. (Note: currently
* this is a no-op because RLS conditions aren't added till later, but it
* seems like good future-proofing to do this anyway.)
*/
sub_action->hasRowSecurity = (sub_action->hasRowSecurity || parsetree->hasRowSecurity);
* Each rule action's jointree should be the main parsetree's jointree
* plus that rule's jointree, but usually *without* the original rtindex
* that we're replacing (if present, which it won't be for INSERT). Note
* that if the rule action refers to OLD, its jointree will add a
* reference to rt_index. If the rule action doesn't refer to OLD, but
* either the rule_qual or the user query quals do, then we need to keep
* the original rtindex in the jointree to provide data for the quals. We
* don't want the original rtindex to be joined twice, however, so avoid
* keeping it if the rule action mentions it.
*
* As above, the action's jointree must not share substructure with the
* main parsetree's.
*/
if (sub_action->commandType != CMD_UTILITY) {
bool keeporig = false;
List* newjointree = NIL;
AssertEreport(sub_action->jointree != NULL, MOD_OPT, "");
keeporig = (!rangeTableEntry_used((Node*)sub_action->jointree, rt_index, 0)) &&
(rangeTableEntry_used(rule_qual, rt_index, 0) ||
rangeTableEntry_used(parsetree->jointree->quals, rt_index, 0));
newjointree = adjustJoinTreeList(parsetree, !keeporig, rt_index);
if (newjointree != NIL) {
* If sub_action is a setop, manipulating its jointree will do no
* good at all, because the jointree is dummy. (Perhaps someday
* we could push the joining and quals down to the member
* statements of the setop?)
*/
if (sub_action->setOperations != NULL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("conditional UNION/INTERSECT/EXCEPT statements are not implemented")));
sub_action->jointree->fromlist = list_concat(newjointree, sub_action->jointree->fromlist);
* There could have been some SubLinks in newjointree, in which
* case we'd better mark the sub_action correctly.
*/
if (parsetree->hasSubLinks && !sub_action->hasSubLinks)
sub_action->hasSubLinks = checkExprHasSubLink((Node*)newjointree);
}
}
* If the original query has any CTEs, copy them into the rule action. But
* we don't need them for a utility action.
*/
if (parsetree->cteList != NIL && sub_action->commandType != CMD_UTILITY) {
ListCell* lc = NULL;
* Annoying implementation restriction: because CTEs are identified by
* name within a cteList, we can't merge a CTE from the original query
* if it has the same name as any CTE in the rule action.
*
* This could possibly be fixed by using some sort of internally
* generated ID, instead of names, to link CTE RTEs to their CTEs.
*/
foreach (lc, parsetree->cteList) {
CommonTableExpr* cte = (CommonTableExpr*)lfirst(lc);
ListCell* lc2 = NULL;
foreach (lc2, sub_action->cteList) {
CommonTableExpr* cte2 = (CommonTableExpr*)lfirst(lc2);
if (strcmp(cte->ctename, cte2->ctename) == 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("WITH query name \"%s\" appears in both a rule action and the query being rewritten",
cte->ctename)));
}
}
sub_action->cteList = list_concat(sub_action->cteList, (List*)copyObject(parsetree->cteList));
}
* Event Qualification forces copying of parsetree and splitting into two
* queries one w/rule_qual, one w/NOT rule_qual. Also add user query qual
* onto rule action
*/
AddQual(sub_action, rule_qual);
AddQual(sub_action, parsetree->jointree->quals);
* Rewrite new.attribute with right hand side of target-list entry for
* appropriate field name in insert/update.
*
* KLUGE ALERT: since ReplaceVarsFromTargetList returns a mutated copy, we
* can't just apply it to sub_action; we have to remember to update the
* sublink inside rule_action, too.
*/
if ((event == CMD_INSERT || event == CMD_UPDATE) && sub_action->commandType != CMD_UTILITY) {
sub_action = (Query*)ReplaceVarsFromTargetList((Node*)sub_action,
new_varno,
0,
rt_fetch(new_varno, sub_action->rtable),
parsetree->targetList,
(event == CMD_UPDATE) ?
REPLACEVARS_CHANGE_VARNO :
REPLACEVARS_SUBSTITUTE_NULL,
current_varno,
NULL);
if (sub_action_ptr != NULL)
*sub_action_ptr = sub_action;
else
rule_action = sub_action;
}
* If rule_action has a RETURNING clause, then either throw it away if the
* triggering query has no RETURNING clause, or rewrite it to emit what
* the triggering query's RETURNING clause asks for. Throw an error if
* more than one rule has a RETURNING clause.
*/
if (!parsetree->returningList)
rule_action->returningList = NIL;
else if (rule_action->returningList) {
if (*returning_flag)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot have RETURNING lists in multiple rules")));
*returning_flag = true;
rule_action->returningList = (List*)ReplaceVarsFromTargetList((Node*)parsetree->returningList,
linitial_int(parsetree->resultRelations),
0,
rt_fetch(linitial_int(parsetree->resultRelations), parsetree->rtable),
rule_action->returningList,
REPLACEVARS_REPORT_ERROR,
0,
&rule_action->hasSubLinks);
* There could have been some SubLinks in parsetree's returningList,
* in which case we'd better mark the rule_action correctly.
*/
if (parsetree->hasSubLinks && !rule_action->hasSubLinks)
rule_action->hasSubLinks = checkExprHasSubLink((Node*)rule_action->returningList);
}
return rule_action;
}
* Copy the query's jointree list, and optionally attempt to remove any
* occurrence of the given rt_index as a top-level join item (we do not look
* for it within join items; this is OK because we are only expecting to find
* it as an UPDATE or DELETE target relation, which will be at the top level
* of the join). Returns modified jointree list --- this is a separate copy
* sharing no nodes with the original.
*/
static List* adjustJoinTreeList(Query* parsetree, bool removert, int rt_index)
{
List* newjointree = (List*)copyObject(parsetree->jointree->fromlist);
ListCell* l = NULL;
if (removert) {
foreach (l, newjointree) {
RangeTblRef* rtr = (RangeTblRef*)lfirst(l);
if (IsA(rtr, RangeTblRef) && rtr->rtindex == rt_index) {
newjointree = list_delete_ptr(newjointree, rtr);
* foreach is safe because we exit loop after list_delete...
*/
break;
}
}
}
return newjointree;
}
* rewriteTargetListIU - rewrite INSERT/UPDATE targetlist into standard form
*
* This has the following responsibilities:
*
* 1. For an INSERT, add tlist entries to compute default values for any
* attributes that have defaults and are not assigned to in the given tlist.
* (We do not insert anything for default-less attributes, however. The
* planner will later insert NULLs for them, but there's no reason to slow
* down rewriter processing with extra tlist nodes.) Also, for both INSERT
* and UPDATE, replace explicit DEFAULT specifications with column default
* expressions.
*
* 2. For an UPDATE on a trigger-updatable view, add tlist entries for any
* unassigned-to attributes, assigning them their old values. These will
* later get expanded to the output values of the view. (This is equivalent
* to what the planner's expand_targetlist() will do for UPDATE on a regular
* table, but it's more convenient to do it here while we still have easy
* access to the view's original RT index.) This is only necessary for
* trigger-updatable views, for which the view remains the result relation of
* the query. For auto-updatable views we must not do this, since it might
* add assignments to non-updatable view columns. For rule-updatable views it
* is unnecessary extra work, since the query will be rewritten with a
* different result relation which will be processed when we recurse via
* RewriteQuery.
*
* 3. Merge multiple entries for the same target attribute, or declare error
* if we can't. Multiple entries are only allowed for INSERT/UPDATE of
* portions of an array or record field, for example
* UPDATE table SET foo[2] = 42, foo[4] = 43;
* We can merge such operations into a single assignment op. Essentially,
* the expression we want to produce in this case is like
* foo = array_set(array_set(foo, 2, 42), 4, 43)
*
* 4. Sort the tlist into standard order: non-junk fields in order by resno,
* then junk fields (these in no particular order).
*
* We must do items 1,2,3 before firing rewrite rules, else rewritten
* references to NEW.foo will produce wrong or incomplete results. Item 4
* is not needed for rewriting, but will be needed by the planner, and we
* can do it essentially for free while handling the other items.
*
* If attrno_list isn't NULL, we return an additional output besides the
* rewritten targetlist: an integer list of the assigned-to attnums, in
* order of the original tlist's non-junk entries. This is needed for
* processing VALUES RTEs.
*/
static List* rewriteTargetListIU(List* targetList, CmdType commandType, Relation target_relation,
int result_rtindex, List** attrno_list, bool* hasGenCol)
{
TargetEntry** new_tles;
List* new_tlist = NIL;
List* junk_tlist = NIL;
Form_pg_attribute att_tup;
int attrno, next_junk_attrno, numattrs;
ListCell* temp = NULL;
if (attrno_list != NULL)
*attrno_list = NIL;
* We process the normal (non-junk) attributes by scanning the input tlist
* once and transferring TLEs into an array, then scanning the array to
* build an output tlist. This avoids O(N^2) behavior for large numbers
* of attributes.
*
* Junk attributes are tossed into a separate list during the same tlist
* scan, then appended to the reconstructed tlist.
*/
numattrs = RelationGetNumberOfAttributes(target_relation);
new_tles = (TargetEntry**)palloc0(numattrs * sizeof(TargetEntry*));
next_junk_attrno = numattrs + 1;
foreach (temp, targetList) {
TargetEntry* old_tle = (TargetEntry*)lfirst(temp);
if (!old_tle->resjunk) {
attrno = old_tle->resno;
if (attrno < 1 || attrno > numattrs) {
ereport(ERROR,
(errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("bogus resno %d in targetlist", attrno)));
}
att_tup = &target_relation->rd_att->attrs[attrno - 1];
if (attrno_list != NULL && IsA(old_tle->expr, Var))
*attrno_list = lappend_int(*attrno_list, attrno);
if (att_tup->attisdropped)
continue;
new_tles[attrno - 1] = process_matched_tle(old_tle, new_tles[attrno - 1], NameStr(att_tup->attname));
} else {
* Copy all resjunk tlist entries to junk_tlist, and assign them
* resnos above the last real resno.
*
* Typical junk entries include ORDER BY or GROUP BY expressions
* (are these actually possible in an INSERT or UPDATE?), system
* attribute references, etc.
*
* Get the resno right, but don't copy unnecessarily
*/
if (old_tle->resno != next_junk_attrno) {
old_tle = flatCopyTargetEntry(old_tle);
old_tle->resno = next_junk_attrno;
}
junk_tlist = lappend(junk_tlist, old_tle);
next_junk_attrno++;
}
}
for (attrno = 1; attrno <= numattrs; attrno++) {
TargetEntry* new_tle = new_tles[attrno - 1];
bool applyDefault = false;
bool generateCol = ISGENERATEDCOL(target_relation->rd_att, attrno - 1);
att_tup = &target_relation->rd_att->attrs[attrno - 1];
if (att_tup->attisdropped)
continue;
* Handle the two cases where we need to insert a default expression:
* it's an INSERT and there's no tlist entry for the column, or the
* tlist entry is a DEFAULT placeholder node.
*/
applyDefault = ((new_tle == NULL && commandType == CMD_INSERT) ||
(new_tle != NULL && new_tle->expr != NULL && IsA(new_tle->expr, SetToDefault)));
if (generateCol && !applyDefault) {
if (commandType == CMD_INSERT && attrno_list == NULL) {
ereport(ERROR, (errmodule(MOD_GEN_COL), errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot insert into column \"%s\"", NameStr(att_tup->attname)),
errdetail("Column \"%s\" is a generated column.", NameStr(att_tup->attname))));
}
if (commandType == CMD_UPDATE && new_tle) {
ereport(ERROR, (errmodule(MOD_GEN_COL), errcode(ERRCODE_SYNTAX_ERROR),
errmsg("column \"%s\" can only be updated to DEFAULT", NameStr(att_tup->attname)),
errdetail("Column \"%s\" is a generated column.", NameStr(att_tup->attname))));
}
}
if (generateCol) {
* stored generated column will be fixed in executor
*/
new_tle = NULL;
*hasGenCol = true;
} else if (applyDefault) {
Node* new_expr = NULL;
new_expr = build_column_default(target_relation, attrno, true);
* If there is no default (ie, default is effectively NULL), we
* can omit the tlist entry in the INSERT case, since the planner
* can insert a NULL for itself, and there's no point in spending
* any more rewriter cycles on the entry. But in the UPDATE case
* we've got to explicitly set the column to NULL.
*/
if (new_expr == NULL) {
if (commandType == CMD_INSERT) {
new_tle = NULL;
ereport(DEBUG2, (errmodule(MOD_PARSER), errcode(ERRCODE_LOG),
errmsg("default column \"%s\" is effectively NULL, and hence omitted.",
NameStr(att_tup->attname))));
} else if (target_relation->rd_rel->relkind != RELKIND_VIEW) {
new_expr = (Node*)makeConst(att_tup->atttypid,
-1,
att_tup->attcollation,
att_tup->attlen,
(Datum)0,
true,
att_tup->attbyval);
new_expr = coerce_to_domain(
new_expr, InvalidOid, -1, att_tup->atttypid, COERCE_IMPLICIT_CAST,
NULL, NULL, -1, false, false);
}
}
if (new_expr != NULL)
new_tle = makeTargetEntry((Expr*)new_expr, attrno, pstrdup(NameStr(att_tup->attname)), false);
}
* For an UPDATE on a view, provide a dummy entry whenever there is no
* explicit assignment.
*/
if (new_tle == NULL && commandType == CMD_UPDATE && ((target_relation->rd_rel->relkind == RELKIND_VIEW
&& view_has_instead_trigger(target_relation, CMD_UPDATE))
|| target_relation->rd_rel->relkind == RELKIND_CONTQUERY)) {
Node* new_expr = NULL;
new_expr = (Node*)makeVar(
result_rtindex, attrno, att_tup->atttypid, att_tup->atttypmod, att_tup->attcollation, 0);
new_tle = makeTargetEntry((Expr*)new_expr, attrno, pstrdup(NameStr(att_tup->attname)), false);
}
if (new_tle != NULL)
new_tlist = lappend(new_tlist, new_tle);
}
pfree_ext(new_tles);
targetList = list_concat(new_tlist, junk_tlist);
return targetList;
}
static void rewriteTargetListMutilUpdate(Query* parsetree, List* rtable, List* resultRelations)
{
TargetEntry** new_tles;
List* new_tlist = NIL;
List* junk_tlist = NIL;
Form_pg_attribute att_tup;
int attrno, numattrs;
ListCell* l = NULL;
int result_relation;
* We process the normal (non-junk) attributes by scanning the input tlist
* once and transferring TLEs into an array, then scanning the array to
* build an output tlist. This avoids O(N^2) behavior for large numbers
* of attributes.
*
* Junk attributes are tossed into a separate list during the same tlist
* scan, then appended to the reconstructed tlist.
*/
ListCell* temp = list_head(parsetree->targetList);
TargetEntry* old_tle = (TargetEntry*)lfirst(temp);
foreach (l, resultRelations) {
result_relation = lfirst_int(l);
Assert(((TargetEntry*)lfirst(temp))->rtindex == (Index)result_relation);
RangeTblEntry* rt_entry = rt_fetch(result_relation, rtable);
Relation target_relation = heap_open(rt_entry->relid, NoLock);
numattrs = RelationGetNumberOfAttributes(target_relation);
new_tles = (TargetEntry**)palloc0(numattrs * sizeof(TargetEntry*));
while (temp != NULL) {
old_tle = (TargetEntry*)lfirst(temp);
* For multi-relations update, old_tle has been sorted according to the order of each result relation.
* So when old_tle->rtindex != (Index)result_relation, break and process the next step.
*/
if (old_tle->rtindex != (Index)result_relation)
break;
if (!old_tle->resjunk) {
attrno = old_tle->resno;
if (attrno < 1 || attrno > numattrs) {
ereport(ERROR,
(errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("bogus resno %d in targetlist",
attrno)));
}
att_tup = &target_relation->rd_att->attrs[attrno - 1];
if (att_tup->attisdropped) {
temp = lnext(temp);
continue;
}
new_tles[attrno - 1] = process_matched_tle(old_tle, new_tles[attrno - 1], NameStr(att_tup->attname));
} else {
* Copy all resjunk tlist entries to junk_tlist, and assign them
* resnos above the last real resno.
*
* Typical junk entries include ORDER BY or GROUP BY expressions
* (are these actually possible in an INSERT or UPDATE?), system
* attribute references, etc.
*
* Get the resno right, but don't copy unnecessarily
*/
old_tle = flatCopyTargetEntry(old_tle);
junk_tlist = lappend(junk_tlist, old_tle);
}
temp = lnext(temp);
}
for (attrno = 1; attrno <= numattrs; attrno++) {
TargetEntry* new_tle = new_tles[attrno - 1];
* We need to insert a default expression when the
* tlist entry is a DEFAULT placeholder node.
*/
bool applyDefault = new_tle != NULL && new_tle->expr != NULL && IsA(new_tle->expr, SetToDefault);
bool generateCol = ISGENERATEDCOL(target_relation->rd_att, attrno - 1);
att_tup = &target_relation->rd_att->attrs[attrno - 1];
if (att_tup->attisdropped)
continue;
if (generateCol && !applyDefault && new_tle) {
ereport(ERROR, (errmodule(MOD_GEN_COL), errcode(ERRCODE_SYNTAX_ERROR),
errmsg("column \"%s\" can only be updated to DEFAULT", NameStr(att_tup->attname)),
errdetail("Column \"%s\" is a generated column.", NameStr(att_tup->attname))));
}
if (generateCol) {
* stored generated column will be fixed in executor
*/
new_tle = NULL;
} else if (applyDefault) {
Node* new_expr = build_column_default(target_relation, attrno, true);
if (new_expr == NULL && target_relation->rd_rel->relkind != RELKIND_VIEW) {
new_expr = (Node*)makeConst(att_tup->atttypid,
-1,
att_tup->attcollation,
att_tup->attlen,
(Datum)0,
true,
att_tup->attbyval);
new_expr = coerce_to_domain(
new_expr, InvalidOid, -1, att_tup->atttypid, COERCE_IMPLICIT_CAST,
NULL, NULL, -1, false, false);
}
if (new_expr != NULL) {
new_tle = makeTargetEntry((Expr*)new_expr, attrno, pstrdup(NameStr(att_tup->attname)), false);
}
new_tle->rtindex = result_relation;
}
* For an UPDATE on a view, provide a dummy entry whenever there is no
* explicit assignment.
*/
if (new_tle == NULL && ((target_relation->rd_rel->relkind == RELKIND_VIEW
&& view_has_instead_trigger(target_relation, CMD_UPDATE))
|| target_relation->rd_rel->relkind == RELKIND_CONTQUERY)) {
Node* new_expr = NULL;
new_expr = (Node*)makeVar(
result_relation, attrno, att_tup->atttypid, att_tup->atttypmod, att_tup->attcollation, 0);
new_tle = makeTargetEntry((Expr*)new_expr, attrno, pstrdup(NameStr(att_tup->attname)), false);
new_tle->rtindex = result_relation;
}
if (new_tle != NULL)
new_tlist = lappend(new_tlist, new_tle);
}
heap_close(target_relation, NoLock);
pfree_ext(new_tles);
}
int next_junk_attrno = list_length(new_tlist) + 1;
foreach (l, junk_tlist) {
old_tle = (TargetEntry*)lfirst(l);
if (old_tle->resno != next_junk_attrno) {
old_tle = flatCopyTargetEntry(old_tle);
old_tle->resno = next_junk_attrno;
}
new_tlist = lappend(new_tlist, old_tle);
next_junk_attrno++;
}
parsetree->targetList = new_tlist;
rewriteTargetListMutilUD(parsetree, rtable, resultRelations);
}
static void multiUpdateSetExtraUpdatedCols(Query* parsetree)
{
ListCell* lc = NULL;
RangeTblEntry* rte = NULL;
Relation rel;
foreach (lc, parsetree->resultRelations) {
rte = rt_fetch(lfirst_int(lc), parsetree->rtable);
rel = heap_open(rte->relid, NoLock);
setExtraUpdatedCols(rte, rel->rd_att);
heap_close(rel, NoLock);
}
}
* Convert a matched TLE from the original tlist into a correct new TLE.
*
* This routine detects and handles multiple assignments to the same target
* attribute. (The attribute name is needed only for error messages.)
*/
static TargetEntry* process_matched_tle(TargetEntry* src_tle, TargetEntry* prior_tle, const char* attrName)
{
TargetEntry* result = NULL;
Node* src_expr = NULL;
Node* prior_expr = NULL;
Node* src_input = NULL;
Node* prior_input = NULL;
Node* priorbottom = NULL;
Node* newexpr = NULL;
errno_t errorno = EOK;
if (prior_tle == NULL) {
* Normal case where this is the first assignment to the attribute.
*/
return src_tle;
}
* Multiple assignments to same attribute. Allow only if all are
* FieldStore or ArrayRef assignment operations. This is a bit
* tricky because what we may actually be looking at is a nest of
* such nodes; consider
* UPDATE tab SET col.fld1.subfld1 = x, col.fld2.subfld2 = y
* The two expressions produced by the parser will look like
* FieldStore(col, fld1, FieldStore(placeholder, subfld1, x))
* FieldStore(col, fld2, FieldStore(placeholder, subfld2, x))
* However, we can ignore the substructure and just consider the top
* FieldStore or ArrayRef from each assignment, because it works to
* combine these as
* FieldStore(FieldStore(col, fld1,
* FieldStore(placeholder, subfld1, x)),
* fld2, FieldStore(placeholder, subfld2, x))
* Note the leftmost expression goes on the inside so that the
* assignments appear to occur left-to-right.
*
* For FieldStore, instead of nesting we can generate a single
* FieldStore with multiple target fields. We must nest when
* ArrayRefs are involved though.
* ----------
*/
src_expr = (Node*)src_tle->expr;
prior_expr = (Node*)prior_tle->expr;
src_input = get_assignment_input(src_expr);
prior_input = get_assignment_input(prior_expr);
if (src_input == NULL || prior_input == NULL || exprType(src_expr) != exprType(prior_expr)) {
ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("multiple assignments to same column \"%s\"", attrName)));
}
* Prior TLE could be a nest of assignments if we do this more than once.
*/
priorbottom = prior_input;
for (;;) {
Node* newbottom = get_assignment_input(priorbottom);
if (newbottom == NULL) {
break;
}
priorbottom = newbottom;
}
if (!equal(priorbottom, src_input)) {
ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("multiple assignments to same column \"%s\"", attrName)));
}
* Looks OK to nest 'em.
*/
size_t fstore_len = sizeof(FieldStore);
if (IsA(src_expr, FieldStore)) {
FieldStore* fstore = makeNode(FieldStore);
if (IsA(prior_expr, FieldStore)) {
errorno = memcpy_s(fstore, fstore_len, prior_expr, fstore_len);
securec_check(errorno, "\0", "\0");
fstore->newvals =
list_concat(list_copy(((FieldStore*)prior_expr)->newvals), list_copy(((FieldStore*)src_expr)->newvals));
fstore->fieldnums = list_concat(
list_copy(((FieldStore*)prior_expr)->fieldnums), list_copy(((FieldStore*)src_expr)->fieldnums));
} else {
errorno = memcpy_s(fstore, fstore_len, src_expr, fstore_len);
securec_check(errorno, "\0", "\0");
fstore->arg = (Expr*)prior_expr;
}
newexpr = (Node*)fstore;
} else if (IsA(src_expr, ArrayRef)) {
ArrayRef* aref = makeNode(ArrayRef);
errorno = memcpy_s(aref, sizeof(ArrayRef), src_expr, sizeof(ArrayRef));
securec_check(errorno, "\0", "\0");
aref->refexpr = (Expr*)prior_expr;
newexpr = (Node*)aref;
} else {
ereport(ERROR, (errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("cannot happen")));
newexpr = NULL;
}
result = flatCopyTargetEntry(src_tle);
result->expr = (Expr*)newexpr;
return result;
}
* If node is an assignment node, return its input; else return NULL
*/
static Node* get_assignment_input(Node* node)
{
if (node == NULL)
return NULL;
if (IsA(node, FieldStore)) {
FieldStore* fstore = (FieldStore*)node;
return (Node*)fstore->arg;
} else if (IsA(node, ArrayRef)) {
ArrayRef* aref = (ArrayRef*)node;
if (aref->refassgnexpr == NULL)
return NULL;
return (Node*)aref->refexpr;
}
return NULL;
}
static bool check_sequence_return_numeric_walker(Node *node, int *ret)
{
if (node == NULL) {
*ret = NDE_UNKNOWN;
return false;
}
if (IsA(node, Query)) {
return (Node *)query_tree_walker((Query *)node, (bool (*)())check_sequence_return_numeric_walker,
(void *)ret, 0);
}
if (IsA(node, FuncExpr)) {
FuncExpr *func = (FuncExpr *)node;
if (func->funcid == NEXTVALFUNCOID || func->funcid == CURRVALFUNCOID || func->funcid == LASTVALFUNCOID) {
if (func->funcresulttype == NUMERICOID) {
*ret = NDE_NUMERIC;
return true;
} else {
*ret = NDE_BIGINT;
return true;
}
}
}
return expression_tree_walker(node, (bool (*)())check_sequence_return_numeric_walker, (void *)ret);
}
* Make an expression tree for the default value for a column.
*
* If there is no default, return a NULL instead.
* Add one input arg isInsertCmd to show if current statement is insert.
* If auto truncation function enabled and it is insert statement then
* we use this arg to determin if default should be casted explict.
*/
Node* build_column_default(Relation rel, int attrno, bool isInsertCmd, bool needOnUpdate)
{
TupleDesc rd_att = rel->rd_att;
Form_pg_attribute att_tup = &rd_att->attrs[attrno - 1];
Oid atttype = att_tup->atttypid;
int32 atttypmod = att_tup->atttypmod;
Node* expr = NULL;
Oid exprtype;
* Scan to see if relation has a default for this column.
*/
if (rd_att->constr && rd_att->constr->num_defval > 0) {
AttrDefault* defval = rd_att->constr->defval;
int ndef = rd_att->constr->num_defval;
while (--ndef >= 0) {
if (attrno == defval[ndef].adnum) {
* Found it, convert string representation to node tree.
*
* isInsertCmd is false, has_on_update is true and adbin_on_update is not null character string,
* then doing convert adbin_on_update to expression.
* if adbin is not null character string, then doing convert adbin to expression.
*/
if (needOnUpdate && (!isInsertCmd) && defval[ndef].adbin_on_update != nullptr &&
pg_strcasecmp(defval[ndef].adbin_on_update, "") != 0) {
expr = (Node*)stringToNode_skip_extern_fields(defval[ndef].adbin_on_update);
} else if (defval[ndef].adbin != nullptr && pg_strcasecmp(defval[ndef].adbin, "") != 0) {
expr = (Node*)stringToNode_skip_extern_fields(defval[ndef].adbin);
}
if (t_thrd.proc->workingVersionNum < LARGE_SEQUENCE_VERSION_NUM) {
(void)check_sequence_return_numeric_walker(expr, &(u_sess->opt_cxt.nextval_default_expr_type));
}
break;
}
}
}
if (expr == NULL && !ISGENERATEDCOL(rd_att, attrno - 1)) {
* No per-column default, so look for a default for the type itself.But
* not for generated columns.
*/
expr = get_typdefault(atttype);
}
if (expr == NULL)
return NULL;
if (IsA(expr, AutoIncrement)) {
expr = (Node*)makeConst(INT4OID, -1, InvalidOid, sizeof(int32), Int32GetDatum(0), !att_tup->attnotnull, true);
}
* Make sure the value is coerced to the target column type; this will
* generally be true already, but there seem to be some corner cases
* involving domain defaults where it might not be true. This should match
* the parser's processing of non-defaulted expressions --- see
* transformAssignedExpr().
*/
exprtype = exprType(expr);
expr = coerce_to_target_type(NULL,
expr,
exprtype,
atttype,
atttypmod,
COERCION_ASSIGNMENT,
COERCE_IMPLICIT_CAST,
NULL,
NULL,
-1);
* When td_compatible_truncation is set to on, this part of code will set column default
* value to isExplicte args to true, to let bpchar know one explict cast has been added to
* this default value already.
*/
if (u_sess->attr.attr_sql.td_compatible_truncation && u_sess->attr.attr_sql.sql_compatibility == C_FORMAT &&
isInsertCmd && (atttype == BPCHAROID || atttype == VARCHAROID) && expr != NULL) {
AssertEreport(IsA(expr, FuncExpr), MOD_OPT, "");
FuncExpr* fe = (FuncExpr*)expr;
Const* const_arg = (Const*)llast(fe->args);
if (IsA(const_arg, Const) && const_arg->consttype == BOOLOID)
const_arg->constvalue = (Datum) true;
}
if (expr == NULL)
ereport(ERROR, (errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("column \"%s\" is of type %s but %s expression is of type %s", NameStr(att_tup->attname),
format_type_be(atttype), ISGENERATEDCOL(rd_att, attrno - 1) ? "generated column" : "deault",
format_type_be(exprtype)), errhint("You will need to rewrite or cast the expression.")));
* If there is nextval FuncExpr, we should lock the quoted sequence to avoid deadlock,
* this has beed done in transformFuncExpr. See lockNextvalOnCn for more details.
*/
(void)lockNextvalWalker(expr, NULL);
return expr;
}
static bool searchForDefault(RangeTblEntry* rte)
{
ListCell* lc = NULL;
foreach (lc, rte->values_lists) {
List* sublist = (List*)lfirst(lc);
ListCell* lc2 = NULL;
foreach (lc2, sublist) {
Node* col = (Node*)lfirst(lc2);
if (IsA(col, SetToDefault))
return true;
}
}
return false;
}
static void checkGenDefault(RangeTblEntry* rte, Relation target_relation, List* attrnos, bool hasGenCol)
{
ListCell* lc = NULL;
if (!hasGenCol) {
return ;
}
foreach (lc, rte->values_lists) {
List* sublist = (List*)lfirst(lc);
ListCell* lc2 = NULL;
ListCell* lc3 = NULL;
forboth (lc2, sublist, lc3, attrnos) {
Node* col = (Node*)lfirst(lc2);
int attrno = lfirst_int(lc3);
Form_pg_attribute att_tup = &target_relation->rd_att->attrs[attrno - 1];
bool generatedCol = ISGENERATEDCOL(target_relation->rd_att, attrno - 1);
bool applyDefault = IsA(col, SetToDefault);
if (!applyDefault && generatedCol)
ereport(ERROR, (errmodule(MOD_GEN_COL), errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot insert into column \"%s\"", NameStr(att_tup->attname)),
errdetail("Column \"%s\" is a generated column.", NameStr(att_tup->attname))));
}
}
}
* When processing INSERT ... VALUES with a VALUES RTE (ie, multiple VALUES
* lists), we have to replace any DEFAULT items in the VALUES lists with
* the appropriate default expressions. The other aspects of targetlist
* rewriting need be applied only to the query's targetlist proper.
*
* For an auto-updatable view, each DEFAULT item in the VALUES list is
* replaced with the default from the view, if it has one. Otherwise it is
* left untouched so that the underlying base relation's default can be
* applied instead (when we later recurse to here after rewriting the query
* to refer to the base relation instead of the view).
*
* For other types of relation, including rule- and trigger-updatable views,
* all DEFAULT items are replaced, and if the target relation doesn't have a
* default, the value is explicitly set to NULL.
*
* Additionally, if force_nulls is true, the target relation's defaults are
* ignored and all DEFAULT items in the VALUES list are explicitly set to
* NULL, regardless of the target relation's type. This is used for the
* product queries generated by DO ALSO rules attached to an auto-updatable
* view, for which we will have already called this function with force_nulls
* false. For these product queries, we must then force any remaining DEFAULT
* items to NULL to provide concrete values for the rule actions.
* Essentially, this is a mix of the 2 cases above --- the original query is
* an insert into an auto-updatable view, and the product queries are inserts
* into a rule-updatable view.
*
* Note that we may have subscripted or field assignment targetlist entries,
* as well as more complex expressions from already-replaced DEFAULT items if
* we have recursed to here for an auto-updatable view. However, it ought to
* be impossible for such entries to have DEFAULTs assigned to them --- we
* should only have to replace DEFAULT items for targetlist entries that
* contain simple Vars referencing the VALUES RTE.
*
* Returns true if all DEFAULT items were replaced, and false if some were
* left untouched.
*/
static bool rewriteValuesRTE(Query* parsetree, RangeTblEntry* rte, Relation target_relation, List* attrnos,
bool force_nulls)
{
List* newValues = NIL;
ListCell* lc = NULL;
bool isAutoUpdatableView;
bool allReplaced;
Assert(parsetree->commandType == CMD_INSERT);
Assert(rte->rtekind == RTE_VALUES);
* Rebuilding all the lists is a pretty expensive proposition in a big
* VALUES list, and it's a waste of time if there aren't any DEFAULT
* placeholders. So first scan to see if there are any.
* We skip this check if force_nulls is true, because we know that there
* are DEFAULT items present in that case.
*/
if (!force_nulls && !searchForDefault(rte))
return true;
* Check if the target relation is an auto-updatable view, in which case
* unresolved defaults will be left untouched rather than being set to
* NULL. If force_nulls is true, we always set DEFAULT items to NULL, so
* skip this check in that case --- it isn't an auto-updatable view.
*/
isAutoUpdatableView = false;
if (!force_nulls && target_relation->rd_rel->relkind == RELKIND_VIEW &&
!view_has_instead_trigger(target_relation, CMD_INSERT)) {
List* locks = NIL;
bool found;
ListCell* l = NULL;
locks = matchLocks(CMD_INSERT, target_relation->rd_rules, linitial_int(parsetree->resultRelations), parsetree);
found = false;
foreach (l, locks) {
RewriteRule* rule_lock = (RewriteRule*)lfirst(l);
if (rule_lock->isInstead && rule_lock->qual == NULL) {
found = true;
break;
}
}
* If we didn't find an unconditional DO INSTEAD rule, assume that the
* view is auto-updatable. If it isn't, rewriteTargetView() will
* throw an error.
*/
if (!found)
isAutoUpdatableView = true;
}
newValues = NIL;
allReplaced = true;
foreach (lc, rte->values_lists) {
List* sublist = (List*)lfirst(lc);
List* newList = NIL;
ListCell* lc2 = NULL;
ListCell* lc3 = NULL;
int i = 0;
forboth(lc2, sublist, lc3, attrnos)
{
Node *col = (Node *)lfirst(lc2);
int attrno = lfirst_int(lc3);
Form_pg_attribute att_tup = &target_relation->rd_att->attrs[attrno - 1];
bool generatedCol = ISGENERATEDCOL(target_relation->rd_att, attrno - 1);
bool applyDefault = IsA(col, SetToDefault);
if (applyDefault) {
Node *new_expr = NULL;
if (attrno == 0) {
ereport(ERROR, (errmsg("cannot set value in column %d to DEFAULT", ++i)));
}
if (force_nulls || att_tup->attisdropped || generatedCol)
new_expr = NULL;
else
new_expr = build_column_default(target_relation, attrno, true);
* If there is no default (ie, default is effectively NULL),
* we've got to explicitly set the column to NULL, unless the
* target relation is an auto-updatable view.
*/
if (new_expr == NULL) {
if (isAutoUpdatableView) {
newList = lappend(newList, col);
allReplaced = false;
continue;
}
new_expr = (Node*)makeConst(att_tup->atttypid,
-1,
att_tup->attcollation,
att_tup->attlen,
(Datum)0,
true,
att_tup->attbyval);
new_expr = coerce_to_domain(
new_expr, InvalidOid, -1, att_tup->atttypid, COERCE_IMPLICIT_CAST,
NULL, NULL, -1, false, false);
}
newList = lappend(newList, new_expr);
} else {
newList = lappend(newList, col);
}
}
newValues = lappend(newValues, newList);
}
rte->values_lists = newValues;
return allReplaced;
}
#ifdef PGXC
* pull_qual_vars(Node *node, int varno)
* Extract vars from quals belonging to resultRelation. This function is mainly
* taken from pull_qual_vars_clause(), but since the later does not peek into
* subquery, we need to write this walker.
*
* @param (in) varno:
* the varno of result relation
* pull_qual_vars will returen all vars in current level if do NOT set 'varno' param
*
* @return:
* (1) vars from quals belonging to resultRelation
* (2) all vars from quals if 'varno' is not set
*/
List* pull_qual_vars(Node* node, int varno, int flags, bool nonRepeat)
{
pull_qual_vars_context context;
context.varlist = NIL;
context.sublevels_up = 0;
context.resultRelation = varno;
context.noRepeat = nonRepeat;
(void)query_or_expression_tree_walker(node, (bool (*)())pull_qual_vars_walker, (void*)&context, flags);
return context.varlist;
}
static bool pull_qual_vars_walker(Node* node, pull_qual_vars_context* context)
{
if (node == NULL)
return false;
if (IsA(node, Var)) {
Var* var = (Var*)node;
* Add only if this var belongs to the resultRelation and refers to the table
* from the same query.
* BUT==> if context->resultRelation is not set,
* all var(s) refers to the table from the same query will be included
*/
if ((context->resultRelation == 0 || var->varno == (Index)context->resultRelation) &&
var->varlevelsup == (Index)context->sublevels_up) {
if (context->noRepeat && list_member(context->varlist, var))
return false;
Var* newvar = (Var*)copyObject(var);
newvar->varlevelsup = 0;
context->varlist = lappend(context->varlist, newvar);
}
return false;
}
if (IsA(node, Query)) {
bool result = false;
context->sublevels_up++;
result = query_tree_walker((Query*)node, (bool (*)())pull_qual_vars_walker, (void*)context, 0);
context->sublevels_up--;
return result;
}
return expression_tree_walker(node, (bool (*)())pull_qual_vars_walker, (void*)context);
}
#endif
* rewriteTargetListUD - rewrite UPDATE/DELETE targetlist as needed
*
* This function adds a "junk" TLE that is needed to allow the executor to
* find the original row for the update or delete. When the target relation
* is a regular table, the junk TLE emits the ctid attribute of the original
* row. When the target relation is a view, there is no ctid, so we instead
* emit a whole-row Var that will contain the "old" values of the view row.
* If it's a foreign table, we let the FDW decide what to add.
*
* For UPDATE queries, this is applied after rewriteTargetListIU. The
* ordering isn't actually critical at the moment.
*/
static void rewriteTargetListUD(Query* parsetree, RangeTblEntry* target_rte, Relation target_relation, int rtindex)
{
Var* var = NULL;
const char* attrname = NULL;
TargetEntry* tle = NULL;
#ifdef PGXC
List* var_list = NIL;
ListCell* elt = NULL;
* In openGauss, we need to evaluate quals of the parse tree and determine
* if they are Coordinator quals. If they are, their attribute need to be
* added to target list for evaluation. In case some are found, add them as
* junks in the target list. The junk status will be used by remote UPDATE
* planning to associate correct element to a clause.
* For DELETE, having such columns in target list helps to evaluate Quals
* correctly on Coordinator.
* This list could be reduced to keep only in target list the
* vars using Coordinator Quals.
*/
if (IS_PGXC_COORDINATOR && parsetree->jointree)
var_list = pull_qual_vars((Node*)parsetree->jointree, rtindex);
foreach (elt, var_list) {
Form_pg_attribute att_tup;
int numattrs = RelationGetNumberOfAttributes(target_relation);
var = (Var*)lfirst(elt);
if (var->varattno < 1 || var->varattno > numattrs) {
if (var->varattno < 1) {
RangeTblEntry* rte = rt_fetch(var->varno, parsetree->rtable);
if (LOCATOR_TYPE_REPLICATED == GetLocatorType(rte->relid)) {
t_thrd.postmaster_cxt.forceNoSeparate = true;
}
parsetree->equalVars = lappend(parsetree->equalVars, copyObject(var));
}
continue;
}
att_tup = &target_relation->rd_att->attrs[var->varattno - 1];
tle = makeTargetEntry(
(Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(NameStr(att_tup->attname)), true);
tle->rtindex = rtindex;
parsetree->targetList = lappend(parsetree->targetList, tle);
}
parsetree->equalVars = list_concat(
parsetree->equalVars, pull_qual_vars((Node*)parsetree->targetList, rtindex, 0, true));
if (IS_PGXC_COORDINATOR && RelationGetLocInfo(target_relation) &&
IsRelationReplicated(RelationGetLocInfo(target_relation)) && RelationIsRelation(target_relation)) {
int16* indexed_col = NULL;
int index_col_count = 0;
int counter = 0;
index_col_count = pgxc_find_primarykey(target_relation->rd_id, &indexed_col);
AssertEreport(index_col_count >= 0, MOD_OPT, "");
for (counter = 0; counter < index_col_count; counter++) {
AttrNumber att_no = indexed_col[counter];
HeapTuple heaptuple = NULL;
Form_pg_attribute att_tup = NULL;
Node* new_expr = NULL;
TargetEntry* new_tle = NULL;
if (att_no > 0) {
att_tup = &target_relation->rd_att->attrs[att_no - 1];
} else {
heaptuple =
SearchSysCache2(ATTNUM, ObjectIdGetDatum(RelationGetRelid(target_relation)), Int16GetDatum(att_no));
if (!HeapTupleIsValid(heaptuple))
ereport(ERROR, (errcode(ERRCODE_CACHE_LOOKUP_FAILED),
errmsg("cache lookup failed for attribute %d of relation %u", att_no,
RelationGetRelid(target_relation))));
att_tup = (Form_pg_attribute)GETSTRUCT(heaptuple);
}
new_expr = (Node*)makeVar(
rtindex, att_no, att_tup->atttypid, att_tup->atttypmod, att_tup->attcollation, 0);
new_tle = makeTargetEntry((Expr*)new_expr, list_length(parsetree->targetList) + 1, "xc_primary_key", true);
new_tle->rtindex = rtindex;
parsetree->targetList = lappend(parsetree->targetList, new_tle);
if (att_no <= 0) {
ReleaseSysCache(heaptuple);
}
}
}
#endif
if (target_relation->rd_rel->relkind == RELKIND_RELATION || target_relation->rd_rel->relkind == RELKIND_MATVIEW) {
* Emit CTID so that executor can find the row to update or delete.
*/
var = makeVar(rtindex, SelfItemPointerAttributeNumber, TIDOID, -1, InvalidOid, 0);
attrname = "ctid";
} else if (target_relation->rd_rel->relkind == RELKIND_FOREIGN_TABLE
|| target_relation->rd_rel->relkind == RELKIND_STREAM) {
* Let the foreign table's FDW add whatever junk TLEs it wants.
*/
FdwRoutine* fdwroutine = NULL;
fdwroutine = GetFdwRoutineForRelation(target_relation, false);
if (fdwroutine->AddForeignUpdateTargets != NULL)
fdwroutine->AddForeignUpdateTargets(parsetree, target_rte, target_relation);
return;
} else {
* Emit whole-row Var so that executor will have the "old" view row to
* pass to the INSTEAD OF trigger.
*/
var = makeWholeRowVar(target_rte, rtindex, 0, false);
if (var == NULL) {
ereport(ERROR,(errcode(ERRCODE_UNDEFINED_FILE),
errmsg("Fail to get the previous view row.")));
return;
}
attrname = "wholerow";
}
tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(attrname), true);
tle->rtindex = rtindex;
parsetree->targetList = lappend(parsetree->targetList, tle);
if (target_relation->rd_rel->relkind == RELKIND_RELATION &&
(RELATION_IS_PARTITIONED(target_relation) || RelationIsCUFormat(target_relation))) {
var = makeVar(rtindex, TableOidAttributeNumber, OIDOID, -1, InvalidOid, 0);
attrname = "tableoid";
tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(attrname), true);
tle->rtindex = rtindex;
parsetree->targetList = lappend(parsetree->targetList, tle);
}
if (target_relation->rd_rel->relkind == RELKIND_RELATION && RELATION_HAS_BUCKET(target_relation)) {
var = makeVar(rtindex, BucketIdAttributeNumber, INT2OID, -1, InvalidBktId, 0);
attrname = "tablebucketid";
tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(attrname), true);
tle->rtindex = rtindex;
parsetree->targetList = lappend(parsetree->targetList, tle);
}
#ifdef PGXC
if (IS_PGXC_COORDINATOR && RelationGetLocInfo(target_relation) != NULL &&
target_relation->rd_rel->relkind == RELKIND_RELATION) {
* If relation is non-replicated, we need also to identify the Datanode
* from where tuple is fetched.
*/
if (!IsRelationReplicated(RelationGetLocInfo(target_relation))) {
var = makeVar(rtindex, XC_NodeIdAttributeNumber, INT4OID, -1, InvalidOid, 0);
tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup("xc_node_id"), true);
tle->rtindex = rtindex;
parsetree->targetList = lappend(parsetree->targetList, tle);
}
if (pgxc_trig_oldrow_reqd(target_relation, parsetree->commandType)) {
var = makeWholeRowVar(target_rte, rtindex, 0, false);
tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup("wholerow"), true);
tle->rtindex = rtindex;
parsetree->targetList = lappend(parsetree->targetList, tle);
}
}
#endif
}
static void rewriteTargetListMutilUD(Query* parsetree, List* rtable, List* resultRelations)
{
ListCell* lc;
int result_relation;
RangeTblEntry* rt_entry = NULL;
Relation rt_entry_relation;
foreach (lc, resultRelations) {
result_relation = lfirst_int(lc);
rt_entry = rt_fetch(result_relation, rtable);
AssertEreport(rt_entry->rtekind == RTE_RELATION, MOD_OPT, "");
rt_entry_relation = heap_open(rt_entry->relid, NoLock);
rewriteTargetListUD(parsetree, rt_entry, rt_entry_relation, result_relation);
heap_close(rt_entry_relation, NoLock);
}
}
void rewriteTargetListMerge(Query* parsetree, Index result_relation, List* range_table)
{
Var* var = NULL;
const char* attrname = NULL;
TargetEntry* tle = NULL;
Relation rel;
* The rewriter should have already ensured that the TLEs are in correct
* order; but we have to insert TLEs for any missing attributes.
*
* Scan the tuple description in the relation's relcache entry to make
* sure we have all the user attributes in the right order. We assume
* that the rewriter already acquired at least AccessShareLock on the
* relation, so we need no lock here.
*/
rel = heap_open(getrelid(result_relation, range_table), NoLock);
Assert(rel->rd_rel->relkind == RELKIND_RELATION);
parsetree->targetList = expandTargetTL(parsetree->targetList, parsetree);
* Emit CTID so that executor can find the row to update or delete.
*/
var = makeVar(parsetree->mergeTarget_relation, SelfItemPointerAttributeNumber, TIDOID, -1, InvalidOid, 0);
attrname = "ctid";
tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(attrname), true);
parsetree->targetList = lappend(parsetree->targetList, tle);
if (IS_PGXC_COORDINATOR) {
* Emit xc_node_id so that executor can find the row to update or delete.
*/
var = makeVar(parsetree->mergeTarget_relation, XC_NodeIdAttributeNumber, INT4OID, -1, InvalidOid, 0);
attrname = "xc_node_id";
tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(attrname), true);
parsetree->targetList = lappend(parsetree->targetList, tle);
}
* If we are dealing with partitioned table, then emit TABLEOID so that
* executor can find the partition the row belongs to.
*/
if (RELATION_IS_PARTITIONED(rel) || RelationIsCUFormat(rel)) {
var = makeVar(parsetree->mergeTarget_relation, TableOidAttributeNumber, OIDOID, -1, InvalidOid, 0);
attrname = "tableoid";
tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(attrname), true);
parsetree->targetList = lappend(parsetree->targetList, tle);
}
if (RELATION_HAS_BUCKET(rel)) {
var = makeVar(parsetree->mergeTarget_relation, BucketIdAttributeNumber, INT2OID, -1, InvalidBktId, 0);
attrname = "tablebucketid";
tle = makeTargetEntry((Expr*)var, list_length(parsetree->targetList) + 1, pstrdup(attrname), true);
parsetree->targetList = lappend(parsetree->targetList, tle);
}
heap_close(rel, NoLock);
}
* matchLocks -
* match the list of locks and returns the matching rules
*/
static List* matchLocks(CmdType event, RuleLock* rulelocks, int varno, Query* parsetree)
{
List* matching_locks = NIL;
int nlocks;
int i;
if (rulelocks == NULL)
return NIL;
if (parsetree->commandType != CMD_SELECT) {
if (linitial2_int(parsetree->resultRelations) != varno)
return NIL;
}
nlocks = rulelocks->numLocks;
for (i = 0; i < nlocks; i++) {
RewriteRule* oneLock = rulelocks->rules[i];
* Suppress ON INSERT/UPDATE/DELETE rules that are disabled or
* configured to not fire during the current sessions replication
* role. ON SELECT rules will always be applied in order to keep views
* working even in LOCAL or REPLICA role.
*/
if (oneLock->event != CMD_SELECT) {
if (u_sess->attr.attr_common.SessionReplicationRole == SESSION_REPLICATION_ROLE_REPLICA) {
if (oneLock->enabled == RULE_FIRES_ON_ORIGIN || oneLock->enabled == RULE_DISABLED)
continue;
} else {
if (oneLock->enabled == RULE_FIRES_ON_REPLICA || oneLock->enabled == RULE_DISABLED)
continue;
}
}
if (oneLock->event == event) {
if (parsetree->commandType != CMD_SELECT ||
(oneLock->attrno == -1 ? rangeTableEntry_used((Node*)parsetree, varno, 0)
: attribute_used((Node*)parsetree, varno, oneLock->attrno, 0)))
matching_locks = lappend(matching_locks, oneLock);
}
}
return matching_locks;
}
* ApplyRetrieveRule - expand an ON SELECT rule
*/
static Query* ApplyRetrieveRule(Query* parsetree, RewriteRule* rule, int rt_index, bool relation_level,
Relation relation, List* activeRIRs, bool forUpdatePushedDown)
{
Query* rule_action = NULL;
RangeTblEntry* rte = NULL;
RangeTblEntry* subrte = NULL;
RowMarkClause* rc = NULL;
bool is_flt_frame = parsetree->is_flt_frame;
Oid checkAsUser = InvalidOid;
if (list_length(rule->actions) != 1) {
ereport(ERROR, (errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("expected just one rule action")));
}
if (rule->qual != NULL) {
ereport(
ERROR, (errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("cannot handle qualified ON SELECT rule")));
}
if (!relation_level) {
ereport(ERROR,
(errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE), errmsg("cannot handle per-attribute ON SELECT rule")));
}
if (unlikely(RESTRICT_NONSYSTEM_RELATION_KIND_VIEW && RelationGetRelid(relation) >= FirstNormalObjectId)) {
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("Access to non-system view \"%s\" is restricted.", RelationGetRelationName(relation)),
errcause("Access to non-system view \"%s\" is restricted.", RelationGetRelationName(relation)),
erraction("Check the value of restrict_nonsystem_relation_kind.")));
}
if (rt_index == linitial2_int(parsetree->resultRelations)) {
* We have a view as the result relation of the query, and it wasn't
* rewritten by any rule. This case is supported if there is an
* INSTEAD OF trigger that will trap attempts to insert/update/delete
* view rows. The executor will check that; for the moment just plow
* ahead. We have two cases:
*
* For INSERT, we needn't do anything. The unmodified RTE will serve
* fine as the result relation.
*
* For UPDATE/DELETE, we need to expand the view so as to have source
* data for the operation. But we also need an unmodified RTE to
* serve as the target. So, copy the RTE and add the copy to the
* rangetable. Note that the copy does not get added to the jointree.
* Also note that there's a hack in fireRIRrules to avoid calling this
* function again when it arrives at the copied RTE.
*/
if (parsetree->commandType == CMD_INSERT)
return parsetree;
else if (parsetree->commandType == CMD_UPDATE || parsetree->commandType == CMD_DELETE) {
RangeTblEntry* newrte = NULL;
rte = rt_fetch(rt_index, parsetree->rtable);
newrte = (RangeTblEntry*)copyObject(rte);
parsetree->rtable = (List*)lappend(parsetree->rtable, newrte);
linitial_int(parsetree->resultRelations) = list_length(parsetree->rtable);
parsetree->resultRelation = linitial_int(parsetree->resultRelations);
* There's no need to do permissions checks twice, so wipe out the
* permissions info for the original RTE (we prefer to keep the
* bits set on the result RTE).
*/
rte->requiredPerms = 0;
rte->checkAsUser = InvalidOid;
rte->selectedCols = NULL;
rte->insertedCols = NULL;
rte->updatedCols = NULL;
rte->extraUpdatedCols = NULL;
* For the most part, Vars referencing the view should remain as
* they are, meaning that they implicitly represent OLD values.
* But in the RETURNING list if any, we want such Vars to
* represent NEW values, so change them to reference the new RTE.
*
* Since ChangeVarNodes scribbles on the tree in-place, copy the
* RETURNING list first for safety.
*/
parsetree->returningList = (List*)copyObject(parsetree->returningList);
ChangeVarNodes((Node*)parsetree->returningList, rt_index, linitial2_int(parsetree->resultRelations), 0);
parsetree->withCheckOptions = (List*)copyObject(parsetree->withCheckOptions);
ChangeVarNodes((Node*)parsetree->withCheckOptions, rt_index, linitial2_int(parsetree->resultRelations), 0);
} else {
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("unrecognized commandType: %d", (int)parsetree->commandType)));
}
}
* If FOR [KEY] UPDATE/SHARE of view, be sure we get right initial lock on the
* relations it references.
*/
rc = get_parse_rowmark(parsetree, rt_index);
forUpdatePushedDown = forUpdatePushedDown || (rc != NULL);
* Make a modifiable copy of the view query, and acquire needed locks on
* the relations it mentions.
*/
rule_action = (Query*)copyObject(linitial(rule->actions));
AcquireRewriteLocks(rule_action, forUpdatePushedDown);
* If FOR [KEY] UPDATE/SHARE of view, mark all the contained tables as implicit
* FOR [KEY] UPDATE/SHARE, the same as the parser would have done if the view's
* subquery had been written out explicitly.
*
* Note: we don't consider forUpdatePushedDown here; such marks will be
* made by recursing from the upper level in markQueryForLocking.
*/
if (rc != NULL)
markQueryForLocking(rule_action, (Node*)rule_action->jointree, rc->strength, rc->waitPolicy, true,
rc->waitSec);
rule_action->is_flt_frame = is_flt_frame;
* in B format database ,deal with security options
* cause checkAsUser shoule be seted as definers' oid
* we should do some check here ,after expand views' query definition
*/
rte = rt_fetch(rt_index, parsetree->rtable);
if (DB_IS_CMPT(B_FORMAT) && rte->relkind == RELKIND_VIEW) {
if (RelationHasViewSecurityDefinerOption(relation)) {
checkAsUser = RelationGetOwner(relation);
} else if (RelationHasViewSecurityInvokerOption(relation)) {
checkAsUser = rte->checkAsUser == InvalidOid ? GetUserId() : rte->checkAsUser;
} else {
checkAsUser = RelationGetOwner(relation);
}
query_tree_walker((Query *)rule_action, (bool (*)())viewSecurityPassDown, (void *)&checkAsUser, QTW_EXAMINE_RTES);
} else if (RelationHasViewSecurityOption(relation)) {
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("SQL Security option should only used in view and B format database")));
}
* Recursively expand any view references inside the view.
*
* Note: this must happen after markQueryForLocking. That way, any UPDATE
* permission bits needed for sub-views are initially applied to their
* RTE_RELATION RTEs by markQueryForLocking, and then transferred to their
* OLD rangetable entries by the action below (in a recursive call of this
* routine).
*/
rule_action = fireRIRrules(rule_action, activeRIRs, forUpdatePushedDown);
* Refresh view SRFs
*
* If we create a view when enable_expr_fusion is off, SRFs will not be identified, everything will be okay.
* If user set the guc on later, we get an old rule_action, but actually we have the ability to identify
* SRFs and resolve them. We travel the tule_action to fix hasTargetSRFs in Query.
*
* More detail:
* rule_action
* hasTargetSRFs true
* parsetree->is_flt_frame true, it's ok
* parsetree->is_flt_frame false, modify hasTargetSRFs to false
* hasTargetSRFs false
* parsetree->is_flt_frame, walk and check if it has SRFs
* parsetree->is_flt_frame, it's ok
*/
if (u_sess->attr.attr_common.enable_expr_fusion && u_sess->attr.attr_sql.query_dop_tmp == 1) {
query_check_srf(rule_action);
}
* Now, plug the view query in as a subselect, replacing the relation's
* original RTE.
*/
rte = rt_fetch(rt_index, parsetree->rtable);
rte->rtekind = RTE_SUBQUERY;
rte->relid = InvalidOid;
rte->security_barrier = RelationIsSecurityView(relation);
rte->subquery = rule_action;
rte->inh = false;
* We move the view's permission check data down to its rangetable. The
* checks will actually be done against the OLD entry therein.
*/
subrte = rt_fetch(PRS2_OLD_VARNO, rule_action->rtable);
AssertEreport(subrte->relid == relation->rd_id, MOD_OPT, "");
subrte->requiredPerms = rte->requiredPerms;
subrte->checkAsUser = rte->checkAsUser;
subrte->selectedCols = rte->selectedCols;
subrte->insertedCols = rte->insertedCols;
subrte->updatedCols = rte->updatedCols;
subrte->extraUpdatedCols = rte->extraUpdatedCols;
rte->requiredPerms = 0;
rte->checkAsUser = InvalidOid;
rte->selectedCols = NULL;
rte->insertedCols = NULL;
rte->updatedCols = NULL;
rte->extraUpdatedCols = NULL;
* If FOR [KEY] UPDATE/SHARE of view, mark all the contained tables as implicit
* FOR [KEY] UPDATE/SHARE, the same as the parser would have done if the view's
* subquery had been written out explicitly.
*
* Note: we don't consider forUpdatePushedDown here; such marks will be
* made by recursing from the upper level in markQueryForLocking.
*/
if (rc != NULL)
markQueryForLocking(rule_action, (Node*)rule_action->jointree, rc->strength, rc->waitPolicy, true,
rc->waitSec);
return parsetree;
}
* Recursively mark all relations used by a view as FOR [KEY] UPDATE/SHARE.
*
* This may generate an invalid query, eg if some sub-query uses an
* aggregate. We leave it to the planner to detect that.
*
* NB: this must agree with the parser's transformLockingClause() routine.
* However, unlike the parser we have to be careful not to mark a view's
* OLD and NEW rels for updating. The best way to handle that seems to be
* to scan the jointree to determine which rels are used.
*/
static void markQueryForLocking(Query* qry, Node* jtnode, LockClauseStrength strength, LockWaitPolicy waitPolicy, bool pushedDown,
int waitSec)
{
if (jtnode == NULL)
return;
if (IsA(jtnode, RangeTblRef)) {
int rti = ((RangeTblRef*)jtnode)->rtindex;
RangeTblEntry* rte = rt_fetch(rti, qry->rtable);
if (rte->rtekind == RTE_RELATION) {
applyLockingClause(qry, rti, strength, waitPolicy, pushedDown, waitSec);
rte->requiredPerms |= ACL_SELECT_FOR_UPDATE;
} else if (rte->rtekind == RTE_SUBQUERY) {
applyLockingClause(qry, rti, strength, waitPolicy, pushedDown, waitSec);
markQueryForLocking(rte->subquery, (Node*)rte->subquery->jointree, strength, waitPolicy, true,
waitSec);
}
} else if (IsA(jtnode, FromExpr)) {
FromExpr* f = (FromExpr*)jtnode;
ListCell* l = NULL;
foreach (l, f->fromlist)
markQueryForLocking(qry, (Node*)lfirst(l), strength, waitPolicy, pushedDown, waitSec);
} else if (IsA(jtnode, JoinExpr)) {
JoinExpr* j = (JoinExpr*)jtnode;
markQueryForLocking(qry, j->larg, strength, waitPolicy, pushedDown, waitSec);
markQueryForLocking(qry, j->rarg, strength, waitPolicy, pushedDown, waitSec);
} else
ereport(ERROR,
(errmodule(MOD_OPT_REWRITE),
errcode(ERRCODE_DATA_CORRUPTED),
errmsg("unrecognized node type: %d", (int)nodeTag(jtnode))));
}
* fireRIRonSubLink -
* Apply fireRIRrules() to each SubLink (subselect in expression) found
* in the given tree.
*
* NOTE: although this has the form of a walker, we cheat and modify the
* SubLink nodes in-place. It is caller's responsibility to ensure that
* no unwanted side-effects occur!
*
* This is unlike most of the other routines that recurse into subselects,
* because we must take control at the SubLink node in order to replace
* the SubLink's subselect link with the possibly-rewritten subquery.
*/
static bool fireRIRonSubLink(Node* node, List* activeRIRs)
{
if (node == NULL)
return false;
if (IsA(node, SubLink)) {
SubLink* sub = (SubLink*)node;
sub->subselect = (Node*)fireRIRrules((Query*)sub->subselect, activeRIRs, false);
}
* Do NOT recurse into Query nodes, because fireRIRrules already processed
* subselects of subselects for us.
*/
return expression_tree_walker(node, (bool (*)())fireRIRonSubLink, (void*)activeRIRs);
}
* fireRIRrules -
* Apply all RIR rules on each rangetable entry in a query
*/
static Query* fireRIRrules(Query* parsetree, List* activeRIRs, bool forUpdatePushedDown)
{
int origResultRelation = linitial2_int(parsetree->resultRelations);
int rt_index;
ListCell* lc = NULL;
* don't try to convert this into a foreach loop, because rtable list can
* get changed each time through...
*/
rt_index = 0;
while (rt_index < list_length(parsetree->rtable)) {
RangeTblEntry* rte = NULL;
Relation rel;
List* locks = NIL;
RuleLock* rules = NULL;
RewriteRule* rule = NULL;
int i;
++rt_index;
rte = rt_fetch(rt_index, parsetree->rtable);
* A subquery RTE can't have associated rules, so there's nothing to
* do to this level of the query, but we must recurse into the
* subquery to expand any rule references in it.
*/
if (rte->rtekind == RTE_SUBQUERY) {
rte->subquery = fireRIRrules(
rte->subquery, activeRIRs, (forUpdatePushedDown || get_parse_rowmark(parsetree, rt_index) != NULL));
continue;
}
* Joins and other non-relation RTEs can be ignored completely.
*/
if (rte->rtekind != RTE_RELATION) {
continue;
}
* Always ignore RIR rules for materialized views referenced in
* queries. (This does not prevent refreshing MVs, since they aren't
* referenced in their own query definitions.)
*
* Note: in the future we might want to allow MVs to be conditionally
* expanded as if they were regular views, if they are not scannable.
* In that case this test would need to be postponed till after we've
* opened the rel, so that we could check its state.
*/
if (rte->relkind == RELKIND_MATVIEW) {
continue;
}
* If the table is not referenced in the query, then we ignore it.
* This prevents infinite expansion loop due to new rtable entries
* inserted by expansion of a rule. A table is referenced if it is
* part of the join set (a source table), or is referenced by any Var
* nodes, or is the result table.
*/
if (rt_index != linitial2_int(parsetree->resultRelations) &&
!rangeTableEntry_used((Node*)parsetree, rt_index, 0)) {
continue;
}
* Also, if this is a new result relation introduced by
* ApplyRetrieveRule, we don't want to do anything more with it.
*/
if (rt_index == linitial2_int(parsetree->resultRelations) && rt_index != origResultRelation) {
continue;
}
* We can use NoLock here since either the parser or
* AcquireRewriteLocks should have locked the rel already.
*/
rel = heap_open(rte->relid, NoLock);
* Collect the RIR rules that we must apply
*/
rules = rel->rd_rules;
if (rules == NULL) {
heap_close(rel, NoLock);
continue;
}
for (i = 0; i < rules->numLocks; i++) {
rule = rules->rules[i];
if (rule->event != CMD_SELECT) {
continue;
}
if (rule->attrno > 0) {
if (!attribute_used((Node*)parsetree, rt_index, rule->attrno, 0))
continue;
}
locks = lappend(locks, rule);
}
* If we found any, apply them --- but first check for recursion!
*/
if (locks != NIL) {
ListCell* l = NULL;
if (list_member_oid(activeRIRs, RelationGetRelid(rel))) {
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg(
"infinite recursion detected in rules for relation \"%s\"", RelationGetRelationName(rel))));
}
activeRIRs = lcons_oid(RelationGetRelid(rel), activeRIRs);
foreach (l, locks) {
rule = (RewriteRule*)lfirst(l);
parsetree = ApplyRetrieveRule(
parsetree, rule, rt_index, rule->attrno == -1, rel, activeRIRs, forUpdatePushedDown);
}
activeRIRs = list_delete_first(activeRIRs);
}
heap_close(rel, NoLock);
}
foreach (lc, parsetree->cteList) {
CommonTableExpr* cte = (CommonTableExpr*)lfirst(lc);
cte->ctequery = (Node*)fireRIRrules((Query*)cte->ctequery, activeRIRs, false);
}
* Recurse into sublink subqueries, too. But we already did the ones in
* the rtable and cteList.
*/
if (parsetree->hasSubLinks) {
(void)query_tree_walker(parsetree, (bool (*)())fireRIRonSubLink, (void*)activeRIRs, QTW_IGNORE_RC_SUBQUERIES);
}
* Apply row level security policies. Do this work here because it
* requires special recursion detection if the new quals have sublink
* subqueries, and if we did it in the loop above query_tree_walker would
* then recurse into those quals a second time.
* Only bind R.L.S policies to plan on coordinator node like view. Currently
* R.L.S only suport SELECT, UPDATE, DELETE.
*/
bool SupportRlsOnNode = true;
#ifdef ENABLE_MULTIPLE_NODES
SupportRlsOnNode = IS_PGXC_COORDINATOR;
#endif
if (SupportRlsOnNode &&
((parsetree->commandType == CMD_SELECT) || (parsetree->commandType == CMD_UPDATE) ||
(parsetree->commandType == CMD_DELETE) || (parsetree->commandType == CMD_MERGE))) {
rt_index = 0;
foreach (lc, parsetree->rtable) {
RangeTblEntry* rte = (RangeTblEntry*)lfirst(lc);
List* securityQuals = NIL;
bool hasRowSecurity = false;
bool hasSubLink = false;
rt_index++;
* relation(include partitioned relation)
*/
if ((rte->rtekind != RTE_RELATION) || (rte->relkind != RELKIND_RELATION)) {
continue;
}
Relation targetTable = relation_open(rte->relid, NoLock);
if (!targetTable->rd_optionsValid) {
RelationReloadRdOption(targetTable);
}
GetRlsPolicies(parsetree, rte, targetTable, &securityQuals, rt_index, hasRowSecurity, hasSubLink);
if (securityQuals != NIL) {
* Add the new security barrier quals to the start of the RTE's
* list so that they get applied before any existing barrier quals
* (which would have come from a security-barrier view, and should
* get lower priority than RLS conditions on the table itself).
*/
if (hasSubLink) {
if (list_member_oid(activeRIRs, rte->relid)) {
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("infinite recursion detected, please check the row level security "
"policies for relation \"%s\"",
RelationGetRelationName(targetTable))));
}
activeRIRs = lcons_oid(rte->relid, activeRIRs);
* Get row level security policies just passed back securityQuals and
* there were SubLink, make sure we lock any relations which are referenced.
* These locks would normally be acquired by the parser, but securityQuals
* are added post-parsing.
*/
(void)acquireLocksOnSubLinks((Node*)securityQuals, NULL);
expression_tree_walker((Node*)securityQuals, (bool (*)())fireRIRonSubLink, (void*)activeRIRs);
activeRIRs = list_delete_first(activeRIRs);
parsetree->hasSubLinks = true;
}
rte->securityQuals = list_concat(securityQuals, rte->securityQuals);
}
if (rt_index == linitial2_int(parsetree->resultRelations) && parsetree->commandType == CMD_MERGE &&
rte->securityQuals != NIL) {
ListCell *lc = NULL;
ListCell *next = NULL;
Expr *security_quals_expr = (Expr *)lfirst(list_head(rte->securityQuals));
for (lc = lnext(list_head(rte->securityQuals)); lc != NULL; lc = next) {
next = lnext(lc);
List *lst = list_make2(security_quals_expr, lfirst(lc));
security_quals_expr = makeBoolExpr(AND_EXPR, lst, -1);
}
foreach (lc, parsetree->mergeActionList) {
MergeAction *action = (MergeAction *)lfirst(lc);
if (action->commandType == CMD_UPDATE) {
if (action->qual == NULL) {
action->qual = (Node *)security_quals_expr;
} else {
List *qual_list = list_make2(security_quals_expr, action->qual);
action->qual = (Node *)makeBoolExpr(AND_EXPR, qual_list, -1);
}
rte->securityQuals = NIL;
break;
}
}
}
parsetree->hasRowSecurity = (hasRowSecurity || parsetree->hasRowSecurity);
relation_close(targetTable, NoLock);
}
}
return parsetree;
}
* Modify the given query by adding 'AND rule_qual IS NOT TRUE' to its
* qualification. This is used to generate suitable "else clauses" for
* conditional INSTEAD rules. (Unfortunately we must use "x IS NOT TRUE",
* not just "NOT x" which the planner is much smarter about, else we will
* do the wrong thing when the qual evaluates to NULL.)
*
* The rule_qual may contain references to OLD or NEW. OLD references are
* replaced by references to the specified rt_index (the relation that the
* rule applies to). NEW references are only possible for INSERT and UPDATE
* queries on the relation itself, and so they should be replaced by copies
* of the related entries in the query's own targetlist.
*/
static Query* CopyAndAddInvertedQual(Query* parsetree, Node* rule_qual, int rt_index, CmdType event)
{
Node* new_qual = (Node*)copyObject(rule_qual);
* In case there are subqueries in the qual, acquire necessary locks and
* fix any deleted JOIN RTE entries. (This is somewhat redundant with
* rewriteRuleAction, but not entirely ... consider restructuring so that
* we only need to process the qual this way once.)
*/
(void)acquireLocksOnSubLinks(new_qual, NULL);
ChangeVarNodes(new_qual, PRS2_OLD_VARNO, rt_index, 0);
if (event == CMD_INSERT || event == CMD_UPDATE)
new_qual = ReplaceVarsFromTargetList(new_qual,
PRS2_NEW_VARNO,
0,
rt_fetch(rt_index, parsetree->rtable),
parsetree->targetList,
(event == CMD_UPDATE) ?
REPLACEVARS_CHANGE_VARNO :
REPLACEVARS_SUBSTITUTE_NULL,
rt_index,
&parsetree->hasSubLinks);
AddInvertedQual(parsetree, new_qual);
return parsetree;
}
* Generated column can not be manually insert or updated.
*/
static void CheckGeneratedColConstraint(CmdType commandType, Form_pg_attribute attTup, const TargetEntry *newTle)
{
if (commandType == CMD_INSERT) {
ereport(ERROR, (errmodule(MOD_GEN_COL), errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot insert into column \"%s\"", NameStr(attTup->attname)),
errdetail("Column \"%s\" is a generated column.", NameStr(attTup->attname))));
} else if (commandType == CMD_UPDATE && newTle) {
ereport(ERROR, (errmodule(MOD_GEN_COL), errcode(ERRCODE_SYNTAX_ERROR),
errmsg("column \"%s\" can only be updated to DEFAULT", NameStr(attTup->attname)),
errdetail("Column \"%s\" is a generated column.", NameStr(attTup->attname))));
}
}
* very same to pg's rewriteTargetListIU. we adapt it to use for MergeInto
*/
static List* rewriteTargetListMergeInto(
List* targetList, CmdType commandType, Relation target_relation, int result_rti, List** attrno_list)
{
TargetEntry** new_tles;
List* new_tlist = NIL;
List* junk_tlist = NIL;
Form_pg_attribute att_tup;
int attrno, next_junk_attrno, numattrs;
ListCell* temp = NULL;
if (attrno_list != NULL)
*attrno_list = NIL;
* We process the normal (non-junk) attributes by scanning the input tlist
* once and transferring TLEs into an array, then scanning the array to
* build an output tlist. This avoids O(N^2) behavior for large numbers
* of attributes.
*
* Junk attributes are tossed into a separate list during the same tlist
* scan, then appended to the reconstructed tlist.
*/
numattrs = RelationGetNumberOfAttributes(target_relation);
new_tles = (TargetEntry**)palloc0(numattrs * sizeof(TargetEntry*));
next_junk_attrno = numattrs + 1;
foreach (temp, targetList) {
TargetEntry* old_tle = (TargetEntry*)lfirst(temp);
if (!old_tle->resjunk) {
attrno = old_tle->resno;
if (attrno < 1 || attrno > numattrs) {
ereport(ERROR, (errcode(ERRCODE_AMBIGUOUS_COLUMN), errmsg("bogus resno %d in targetlist", attrno)));
}
att_tup = &target_relation->rd_att->attrs[attrno - 1];
if (attrno_list != NULL)
*attrno_list = lappend_int(*attrno_list, attrno);
if (att_tup->attisdropped)
continue;
new_tles[attrno - 1] = process_matched_tle(old_tle, new_tles[attrno - 1], NameStr(att_tup->attname));
} else {
* Copy all resjunk tlist entries to junk_tlist, and assign them
* resnos above the last real resno.
*
* Typical junk entries include ORDER BY or GROUP BY expressions
* (are these actually possible in an INSERT or UPDATE?), system
* attribute references, etc.
*/
if (old_tle->resno != next_junk_attrno) {
old_tle = flatCopyTargetEntry(old_tle);
old_tle->resno = next_junk_attrno;
}
junk_tlist = lappend(junk_tlist, old_tle);
next_junk_attrno++;
}
}
for (attrno = 1; attrno <= numattrs; attrno++) {
TargetEntry* new_tle = new_tles[attrno - 1];
bool apply_default = false;
att_tup = &target_relation->rd_att->attrs[attrno - 1];
if (att_tup->attisdropped)
continue;
* Handle the two cases where we need to insert a default expression:
* it's an INSERT and there's no tlist entry for the column, or the
* tlist entry is a DEFAULT placeholder node.
*/
apply_default = ((new_tle == NULL && commandType == CMD_INSERT) ||
(new_tle && new_tle->expr && IsA(new_tle->expr, SetToDefault)));
bool isGeneratedCol = ISGENERATEDCOL(target_relation->rd_att, attrno - 1);
if (isGeneratedCol) {
if (!apply_default) {
CheckGeneratedColConstraint(commandType, att_tup, new_tle);
}
* stored generated column will be fixed in executor
*/
new_tle = NULL;
} else if (apply_default) {
Node* new_expr = NULL;
new_expr = build_column_default(target_relation, attrno, (commandType == CMD_INSERT));
* If there is no default (ie, default is effectively NULL), we
* can omit the tlist entry in the INSERT case, since the planner
* can insert a NULL for itself, and there's no point in spending
* any more rewriter cycles on the entry. But in the UPDATE case
* we've got to explicitly set the column to NULL.
*/
if (new_expr == NULL) {
if (commandType == CMD_INSERT)
new_tle = NULL;
else {
new_expr = (Node*)makeConst(att_tup->atttypid,
-1,
att_tup->attcollation,
att_tup->attlen,
(Datum)0,
true,
att_tup->attbyval);
new_expr = coerce_to_domain(
new_expr, InvalidOid, -1, att_tup->atttypid, COERCE_IMPLICIT_CAST,
NULL, NULL, -1, false, false);
}
}
if (new_expr != NULL)
new_tle = makeTargetEntry((Expr*)new_expr, attrno, pstrdup(NameStr(att_tup->attname)), false);
}
if (new_tle != NULL)
new_tlist = lappend(new_tlist, new_tle);
}
pfree_ext(new_tles);
return list_concat(new_tlist, junk_tlist);
}
* fireRules -
* Iterate through rule locks applying rules.
*
* Input arguments:
* parsetree - original query
* rt_index - RT index of result relation in original query
* event - type of rule event
* locks - list of rules to fire
* Output arguments:
* *instead_flag - set TRUE if any unqualified INSTEAD rule is found
* (must be initialized to FALSE)
* *returning_flag - set TRUE if we rewrite RETURNING clause in any rule
* (must be initialized to FALSE)
* *qual_product - filled with modified original query if any qualified
* INSTEAD rule is found (must be initialized to NULL)
* Return value:
* list of rule actions adjusted for use with this query
*
* Qualified INSTEAD rules generate their action with the qualification
* condition added. They also generate a modified version of the original
* query with the negated qualification added, so that it will run only for
* rows that the qualified action doesn't act on. (If there are multiple
* qualified INSTEAD rules, we AND all the negated quals onto a single
* modified original query.) We won't execute the original, unmodified
* query if we find either qualified or unqualified INSTEAD rules. If
* we find both, the modified original query is discarded too.
*/
static List* fireRules(Query* parsetree, int rt_index, CmdType event, List* locks, bool* instead_flag,
bool* returning_flag, Query** qual_product)
{
List* results = NIL;
ListCell* l = NULL;
foreach (l, locks) {
RewriteRule* rule_lock = (RewriteRule*)lfirst(l);
Node* event_qual = rule_lock->qual;
List* actions = rule_lock->actions;
QuerySource qsrc;
ListCell* r = NULL;
if (rule_lock->isInstead) {
if (event_qual != NULL)
qsrc = QSRC_QUAL_INSTEAD_RULE;
else {
qsrc = QSRC_INSTEAD_RULE;
*instead_flag = true;
}
} else
qsrc = QSRC_NON_INSTEAD_RULE;
if (qsrc == QSRC_QUAL_INSTEAD_RULE) {
* If there are INSTEAD rules with qualifications, the original
* query is still performed. But all the negated rule
* qualifications of the INSTEAD rules are added so it does its
* actions only in cases where the rule quals of all INSTEAD rules
* are false. Think of it as the default action in a case. We save
* this in *qual_product so RewriteQuery() can add it to the query
* list after we mangled it up enough.
*
* If we have already found an unqualified INSTEAD rule, then
* *qual_product won't be used, so don't bother building it.
*/
if (!*instead_flag) {
if (*qual_product == NULL)
*qual_product = (Query*)copyObject(parsetree);
*qual_product = CopyAndAddInvertedQual(*qual_product, event_qual, rt_index, event);
}
}
foreach (r, actions) {
Query* rule_action = (Query*)lfirst(r);
if (rule_action->commandType == CMD_NOTHING)
continue;
rule_action = rewriteRuleAction(parsetree, rule_action, event_qual, rt_index, event, returning_flag);
rule_action->querySource = qsrc;
rule_action->canSetTag = false;
results = lappend(results, rule_action);
}
}
return results;
}
* get_view_query - get the Query from a view's _RETURN rule.
*
* Caller should have verified that the relation is a view, and therefore
* we should find an ON SELECT action.
*
* Note that the pointer returned is into the relcache and therefore must
* be treated as read-only to the caller and not modified or scribbled on.
*/
Query* get_view_query(Relation view)
{
int i;
Assert(view->rd_rel->relkind == RELKIND_VIEW);
for (i = 0; i < view->rd_rules->numLocks; i++) {
RewriteRule *rule = view->rd_rules->rules[i];
if (rule->event == CMD_SELECT) {
if (list_length(rule->actions) != 1)
ereport(ERROR, (errmsg("invalid _RETURN rule action specification")));
return (Query*)linitial(rule->actions);
}
}
ereport(ERROR, (errmsg("failed to find _RETURN rule for view")));
return NULL;
}
* view_has_instead_trigger - does view have an INSTEAD OF trigger for event?
*
* If it does, we don't want to treat it as auto-updatable. This test can't
* be folded into view_query_is_auto_updatable because it's not an error
* condition.
*/
bool view_has_instead_trigger(Relation view, CmdType event)
{
TriggerDesc *trigDesc = view->trigdesc;
switch (event) {
case CMD_INSERT:
if (trigDesc && trigDesc->trig_insert_instead_row)
return true;
break;
case CMD_UPDATE:
if (trigDesc && trigDesc->trig_update_instead_row)
return true;
break;
case CMD_DELETE:
if (trigDesc && trigDesc->trig_delete_instead_row)
return true;
break;
default:
ereport(ERROR, (errmsg("unrecognized CmdType: %d", (int)event)));
break;
}
return false;
}
* view_col_is_auto_updatable - test whether the specified column of a view
* is auto-updatable. Returns NULL (if the column can be updated) or a message
* string giving the reason that it cannot be.
*
* Note that the checks performed here are local to this view. We do not check
* whether the referenced column of the underlying base relation is updatable.
*/
static const char* view_col_is_auto_updatable(RangeTblRef* rtr, TargetEntry* tle)
{
Var* var = (Var*)tle->expr;
* For now, the only updatable columns we support are those that are Vars
* referring to user columns of the underlying base relation.
*
* The view targetlist may contain resjunk columns (e.g., a view defined
* like "SELECT * FROM t ORDER BY a+b" is auto-updatable) but such columns
* are not auto-updatable, and in fact should never appear in the outer
* query's targetlist.
*/
if (tle->resjunk)
return gettext_noop("Junk view columns are not updatable.");
if (!IsA(var, Var) || var->varno != (unsigned int)rtr->rtindex || var->varlevelsup != 0)
return gettext_noop("View columns that are not columns of their base relation are not updatable.");
if (var->varattno < 0)
return gettext_noop("View columns that refer to system columns are not updatable.");
if (var->varattno == 0)
return gettext_noop("View columns that return whole-row references are not updatable.");
return NULL;
}
* view_query_is_auto_updatable - test whether the specified view definition
* represents an auto-updatable view. Returns NULL (if the view can be updated)
* or a message string giving the reason that it cannot be.
*
* If checkCols is true, the view is required to have at least one updatable
* column (necessary for INSERT/UPDATE). Otherwise the view's columns are not
* checked for updatability. See also view_cols_are_auto_updatable.
*
* Note that the checks performed here are only based on the view definition.
* We do not check whether any base relations referred to by the view are
* updatable.
*/
struct CheckQueryAutoUpdatableContext {
TargetEntry* tle;
List* rtable;
bool checkCols;
bool found;
};
static bool check_view_query_auto_updatable_walker(Node* node, CheckQueryAutoUpdatableContext* context)
{
TargetEntry* tle = context->tle;
List* rtable = context->rtable;
bool checkCols = context->checkCols;
if (node == NULL || context->found) {
return false;
}
if (IsA(node, RangeTblRef)) {
RangeTblRef* rtr = (RangeTblRef*)node;
RangeTblEntry* base_rte = rt_fetch(rtr->rtindex, rtable);
if (base_rte->rtekind != RTE_SUBQUERY &&
(base_rte->rtekind != RTE_RELATION || (base_rte->relkind != RELKIND_RELATION &&
base_rte->relkind != RELKIND_FOREIGN_TABLE && base_rte->relkind != RELKIND_VIEW))) {
return true;
}
if (checkCols) {
if (view_col_is_auto_updatable(rtr, tle) == NULL) {
context->found = true;
return false;
}
context->found = false;
}
return false;
}
return expression_tree_walker(node, (bool (*)())check_view_query_auto_updatable_walker, (void*)context);
}
struct CheckColsAutoUpdatableContext {
Bitmapset* required_cols;
Bitmapset** updatable_cols;
char** nonUpdatableCol;
List* targetList;
const char* colUpdateDetail;
};
static bool check_view_cols_auto_updatable_walker(Node* node, CheckColsAutoUpdatableContext* context)
{
Bitmapset* required_cols = context->required_cols;
Bitmapset** updatable_cols = context->updatable_cols;
char** nonUpdatableCol = context->nonUpdatableCol;
if (node == NULL) {
return false;
}
if (!IsA(node, RangeTblRef)) {
return expression_tree_walker(node, (bool (*)())check_view_cols_auto_updatable_walker,
(void*)context);
}
RangeTblRef* rtr = (RangeTblRef*)node;
AttrNumber col;
ListCell* cell = NULL;
if (updatable_cols != NULL)
*updatable_cols = NULL;
if (nonUpdatableCol != NULL)
*nonUpdatableCol = NULL;
col = -FirstLowInvalidHeapAttributeNumber;
foreach (cell, context->targetList) {
TargetEntry* tle = (TargetEntry*)lfirst(cell);
const char* colUpdateDetail;
col++;
colUpdateDetail = view_col_is_auto_updatable(rtr, tle);
if (colUpdateDetail == NULL) {
if (updatable_cols != NULL)
*updatable_cols = bms_add_member(*updatable_cols, col);
} else if (bms_is_member(col, required_cols)) {
if ((!IsA(tle->expr, Var)) || rtr->rtindex == ((Var*)(tle->expr))->varno) {
if (nonUpdatableCol != NULL)
*nonUpdatableCol = tle->resname;
context->colUpdateDetail = colUpdateDetail;
return true;
}
}
}
return false;
}
static const char* CommonUpdateCheck(Query* viewquery)
{
* Check if the view is simply updatable. According to SQL-92 this means:
* - No DISTINCT clause.
* - Each TLE is a column reference, and each column appears at most once.
* - FROM contains exactly one base relation.
* - No GROUP BY or HAVING clauses.
* - No set operations (UNION, INTERSECT or EXCEPT).
* - No sub-queries in the WHERE clause that reference the target table.
*
* We ignore that last restriction since it would be complex to enforce
* and there isn't any actual benefit to disallowing sub-queries. (The
* semantic issues that the standard is presumably concerned about don't
* arise in Postgres, since any such sub-query will not see any updates
* executed by the outer query anyway, thanks to MVCC snapshotting.)
*
* We also relax the second restriction by supporting part of SQL:1999
* feature T111, which allows for a mix of updatable and non-updatable
* columns, provided that an INSERT or UPDATE doesn't attempt to assign to
* a non-updatable column.
*
* In addition we impose these constraints, involving features that are
* not part of SQL-92:
* - No CTEs (WITH clauses).
* - No OFFSET or LIMIT clauses (this matches a SQL:2008 restriction).
* - No system columns (including whole-row references) in the tlist.
* - No window functions in the tlist.
* - No set-returning functions in the tlist.
*
* Note that we do these checks without recursively expanding the view.
* If the base relation is a view, we'll recursively deal with it later.
*----------
*/
if (viewquery->distinctClause != NIL) {
return gettext_noop("Views containing DISTINCT are not automatically updatable.");
}
if (viewquery->groupClause != NIL) {
return gettext_noop("Views containing GROUP BY are not automatically updatable.");
}
if (viewquery->havingQual != NULL) {
return gettext_noop("Views containing HAVING are not automatically updatable.");
}
if (viewquery->setOperations != NULL) {
return gettext_noop("Views containing UNION, INTERSECT or EXCEPT are not automatically updatable.");
}
if (viewquery->cteList != NIL) {
return gettext_noop("Views containing WITH are not automatically updatable.");
}
if (viewquery->limitOffset != NULL || viewquery->limitCount != NULL) {
return gettext_noop("Views containing LIMIT or OFFSET are not automatically updatable.");
}
* We must not allow window functions or set returning functions in the
* targetlist. Otherwise we might end up inserting them into the quals of
* the main query. We must also check for aggregates in the targetlist in
* case they appear without a GROUP BY.
*
* These restrictions ensure that each row of the view corresponds to a
* unique row in the underlying base relation.
*/
if (viewquery->hasAggs) {
return gettext_noop("Views that return aggregate functions are not automatically updatable.");
}
if (viewquery->hasWindowFuncs) {
return gettext_noop("Views that return window functions are not automatically updatable.");
}
if (expression_returns_set((Node *) viewquery->targetList)) {
return gettext_noop("Views that return set-returning functions are not automatically updatable.");
}
return NULL;
}
const char* view_query_is_auto_updatable(Query *viewquery, bool checkCols, bool isCreate)
{
const char* autoUpdateDetail = CommonUpdateCheck(viewquery);
if (autoUpdateDetail) {
return autoUpdateDetail;
}
* Check that the view has at least one updatable column. This is required
* for INSERT/UPDATE but not for DELETE.
*/
if (isCreate) {
* The view query should select from a single base relation, which must be
* a table or another view.
*/
if (list_length(viewquery->jointree->fromlist) != 1)
return gettext_noop(
"Views that do not select from a single table or view are not automatically updatable.");
RangeTblRef* rtr = NULL;
RangeTblEntry* base_rte = NULL;
rtr = (RangeTblRef*)linitial(viewquery->jointree->fromlist);
if (!IsA(rtr, RangeTblRef))
return gettext_noop(
"Views that do not select from a single table or view are not automatically updatable.");
base_rte = rt_fetch(rtr->rtindex, viewquery->rtable);
if (base_rte->rtekind != RTE_RELATION || (base_rte->relkind != RELKIND_RELATION &&
base_rte->relkind != RELKIND_FOREIGN_TABLE && base_rte->relkind != RELKIND_VIEW))
return gettext_noop(
"Views that do not select from a single table or view are not automatically updatable.");
* Check that the view has at least one updatable column. This is required
* for INSERT/UPDATE but not for DELETE.
*/
if (checkCols) {
ListCell* cell= NULL;
bool found = false;
foreach (cell, viewquery->targetList) {
TargetEntry* tle = (TargetEntry*)lfirst(cell);
if (view_col_is_auto_updatable(rtr, tle) == NULL) {
found = true;
break;
}
}
if (!found)
return gettext_noop("Views that have no updatable columns are not automatically updatable.");
}
} else {
CheckQueryAutoUpdatableContext context;
context.rtable = viewquery->rtable;
context.checkCols = checkCols;
context.found = false;
ListCell* cell = NULL;
foreach (cell, viewquery->targetList) {
TargetEntry* tle = (TargetEntry*)lfirst(cell);
context.tle = tle;
expression_tree_walker((Node*)(viewquery->jointree->fromlist),
(bool(*)())check_view_query_auto_updatable_walker,
(void*)(&context));
if (context.found) break;
}
if (checkCols && !(context.found))
return gettext_noop("Views that have no updatable columns are not automatically updatable.");
}
return NULL;
}
* view_cols_are_auto_updatable - test whether all of the required columns of
* an auto-updatable view are actually updatable. Returns NULL (if all the
* required columns can be updated) or a message string giving the reason that
* they cannot be.
*
* This should be used for INSERT/UPDATE to ensure that we don't attempt to
* assign to any non-updatable columns.
*
* Additionally it may be used to retrieve the set of updatable columns in the
* view, or if one or more of the required columns is not updatable, the name
* of the first offending non-updatable column.
*
* The caller must have already verified that this is an auto-updatable view
* using view_query_is_auto_updatable.
*
* Note that the checks performed here are only based on the view definition.
* We do not check whether the referenced columns of the base relation are
* updatable.
*/
static const char* view_cols_are_auto_updatable(Query *viewquery, Bitmapset *required_cols,
Bitmapset **updatable_cols, char **nonUpdatableCol)
{
* The caller should have verified that this view is auto-updatable and
* so there should be a single base relation.
*/
CheckColsAutoUpdatableContext context;
context.required_cols = required_cols;
context.updatable_cols = updatable_cols;
context.nonUpdatableCol = nonUpdatableCol;
context.targetList = viewquery->targetList;
context.colUpdateDetail = NULL;
if (expression_tree_walker((Node*)viewquery->jointree->fromlist,
(bool(*)())check_view_cols_auto_updatable_walker,
(void*)(&context))) {
return context.colUpdateDetail;
}
return NULL;
}
* relation_is_updatable - determine which update events the specified
* relation supports.
*
* Note that views may contain a mix of updatable and non-updatable columns.
* For a view to support INSERT/UPDATE it must have at least one updatable
* column, but there is no such restriction for DELETE. If include_cols is
* non-NULL, then only the specified columns are considered when testing for
* updatability.
*
* This is used for the information_schema views, which have separate concepts
* of "updatable" and "trigger updatable". A relation is "updatable" if it
* can be updated without the need for triggers (either because it has a
* suitable RULE, or because it is simple enough to be automatically updated).
* A relation is "trigger updatable" if it has a suitable INSTEAD OF trigger.
* The SQL standard regards this as not necessarily updatable, presumably
* because there is no way of knowing what the trigger will actually do.
* The information_schema views therefore call this function with
* include_triggers = false. However, other callers might only care whether
* data-modifying SQL will work, so they can pass include_triggers = true
* to have trigger updatability included in the result.
*
* The return value is a bitmask of rule event numbers indicating which of
* the INSERT, UPDATE and DELETE operations are supported. (We do it this way
* so that we can test for UPDATE plus DELETE support in a single call.)
*/
int relation_is_updatable(Oid reloid, bool include_triggers, Bitmapset* include_cols)
{
int events = 0;
Relation rel;
RuleLock* rulelocks = NULL;
#define ALL_EVENTS ((1 << CMD_INSERT) | (1 << CMD_UPDATE) | (1 << CMD_DELETE))
rel = try_relation_open(reloid, AccessShareLock);
* If the relation doesn't exist, return zero rather than throwing an
* error. This is helpful since scanning an information_schema view
* under MVCC rules can result in referencing rels that were just
* deleted according to a SnapshotNow probe.
*/
if (rel == NULL)
return 0;
if (rel->rd_rel->relkind == RELKIND_RELATION) {
relation_close(rel, AccessShareLock);
return ALL_EVENTS;
}
rulelocks = rel->rd_rules;
if (rulelocks != NULL) {
int i;
for (i = 0; i < rulelocks->numLocks; i++) {
if (rulelocks->rules[i]->isInstead && rulelocks->rules[i]->qual == NULL) {
events |= ((1 << rulelocks->rules[i]->event) & ALL_EVENTS);
}
}
if (events == ALL_EVENTS) {
relation_close(rel, AccessShareLock);
return events;
}
}
if (include_triggers) {
TriggerDesc *trigDesc = rel->trigdesc;
if (trigDesc) {
if (trigDesc->trig_insert_instead_row)
events |= (1 << CMD_INSERT);
if (trigDesc->trig_update_instead_row)
events |= (1 << CMD_UPDATE);
if (trigDesc->trig_delete_instead_row)
events |= (1 << CMD_DELETE);
if (events == ALL_EVENTS) {
relation_close(rel, AccessShareLock);
return events;
}
}
}
if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE) {
FdwRoutine *fdwroutine = GetFdwRoutineForRelation(rel, false);
if (fdwroutine->IsForeignRelUpdatable != NULL)
events |= fdwroutine->IsForeignRelUpdatable(rel);
else {
if (fdwroutine->ExecForeignInsert != NULL)
events |= (1 << CMD_INSERT);
if (fdwroutine->ExecForeignUpdate != NULL)
events |= (1 << CMD_UPDATE);
if (fdwroutine->ExecForeignDelete != NULL)
events |= (1 << CMD_DELETE);
}
relation_close(rel, AccessShareLock);
return events;
}
if (rel->rd_rel->relkind == RELKIND_VIEW) {
Query* viewquery = get_view_query(rel);
if (view_query_is_auto_updatable(viewquery, false) == NULL) {
Bitmapset* updatable_cols;
int auto_events;
RangeTblRef* rtr;
RangeTblEntry* base_rte;
Oid baseoid;
* Determine which of the view's columns are updatable. If there
* are none within the set of of columns we are looking at, then
* the view doesn't support INSERT/UPDATE, but it may still
* support DELETE.
*/
view_cols_are_auto_updatable(viewquery, NULL, &updatable_cols, NULL);
if (include_cols != NULL)
updatable_cols = bms_int_members(updatable_cols, include_cols);
if (bms_is_empty(updatable_cols))
auto_events = (1 << CMD_DELETE);
else
auto_events = ALL_EVENTS;
* The base relation must also support these update commands.
* Tables are always updatable, but for any other kind of base
* relation we must do a recursive check limited to the columns
* referenced by the locally updatable columns in this view.
*/
rtr = (RangeTblRef*)linitial(viewquery->jointree->fromlist);
base_rte = rt_fetch(rtr->rtindex, viewquery->rtable);
Assert(base_rte->rtekind == RTE_RELATION);
if (base_rte->relkind != RELKIND_RELATION) {
baseoid = base_rte->relid;
include_cols = adjust_view_column_set(updatable_cols, viewquery->targetList);
auto_events &= relation_is_updatable(baseoid,
include_triggers,
include_cols);
}
events |= auto_events;
}
}
relation_close(rel, AccessShareLock);
return events;
}
* adjust_view_column_set - map a set of column numbers according to targetlist
*
* This is used with simply-updatable views to map column-permissions sets for
* the view columns onto the matching columns in the underlying base relation.
* The targetlist is expected to be a list of plain Vars of the underlying
* relation (as per the checks above in view_query_is_auto_updatable).
*/
static Bitmapset* adjust_view_column_set(Bitmapset* cols, List* targetlist)
{
Bitmapset* result = NULL;
Bitmapset* tmpcols = NULL;
AttrNumber col;
tmpcols = bms_copy(cols);
while ((col = bms_first_member(tmpcols)) >= 0) {
AttrNumber attno = col + FirstLowInvalidHeapAttributeNumber;
if (attno == InvalidAttrNumber) {
* There's a whole-row reference to the view. For permissions
* purposes, treat it as a reference to each column available from
* the view. (We should *not* convert this to a whole-row
* reference to the base relation, since the view may not touch
* all columns of the base relation.)
*/
ListCell* lc = NULL;
foreach(lc, targetlist) {
TargetEntry* tle = (TargetEntry *) lfirst(lc);
Var* var = NULL;
if (tle->resjunk)
continue;
var = (Var*)tle->expr;
Assert(IsA(var, Var));
result = bms_add_member(result, var->varattno - FirstLowInvalidHeapAttributeNumber);
}
} else {
* Views do not have system columns, so we do not expect to see
* any other system attnos here. If we do find one, the error
* case will apply.
*/
TargetEntry* tle = get_tle_by_resno(targetlist, attno);
if (tle != NULL && !tle->resjunk && IsA(tle->expr, Var)) {
Var* var = (Var*)tle->expr;
result = bms_add_member(result, var->varattno - FirstLowInvalidHeapAttributeNumber);
} else
ereport(ERROR, (errmsg("attribute number %d not found in view targetlist", attno)));
}
}
bms_free(tmpcols);
return result;
}
* If target relation is already exist in parsetree, make new_rte
* and newRtIndex point to it, and return true.
*/
static bool SetNewRteIfExist(SetNewRteIfExistContext* context, bool deleteExistingTarget = true)
{
Query* parsetree = context->parsetree;
Oid baseRelid = context->baseRelid;
int resultRelation = context->resultRelation;
RangeTblEntry** newRte = context->newRte;
int* newRtIndex = context->newRtIndex;
int rtindex = 1;
bool targetIsExist = false;
ListCell* lc = NULL;
foreach (lc, parsetree->rtable) {
RangeTblEntry* rte = (RangeTblEntry*)lfirst(lc);
if (baseRelid == rte->relid && rtindex != resultRelation) {
if (deleteExistingTarget && list_member_int(parsetree->resultRelations, rtindex))
parsetree->resultRelations = list_delete_int(parsetree->resultRelations, resultRelation);
*newRtIndex = rtindex;
*newRte = rte;
targetIsExist = true;
break;
}
rtindex++;
}
if (targetIsExist) {
ListCell* l = NULL;
foreach (l, parsetree->jointree->fromlist) {
RangeTblRef* rtf = (RangeTblRef*)lfirst(l);
if (rtf->rtindex == resultRelation && deleteExistingTarget) {
parsetree->jointree->fromlist = list_delete_ptr(parsetree->jointree->fromlist, rtf);
break;
}
}
}
return targetIsExist;
}
struct NewRteForRewriteTargetViewContext {
Query* parsetree;
Query* viewquery;
int resultRelation;
Relation view;
RangeTblEntry* view_rte;
FromExpr* view_jointree;
int* newIndexes;
Bitmapset* base_indexes;
Bitmapset* visited_rtes;
};
static void GetNewRte(NewRteForRewriteTargetViewContext* context, RangeTblRef* rtr,
RangeTblEntry** out_base_rte, RangeTblEntry** new_rte, int* newRtIndex)
{
Query* parsetree = context->parsetree;
Query* viewquery = context->viewquery;
int resultRelation = context->resultRelation;
int baseRtIndex = rtr->rtindex;
RangeTblEntry* base_rte = rt_fetch(baseRtIndex, viewquery->rtable);
Relation base_rel;
if (base_rte->rtekind == RTE_RELATION) {
* Up to now, the base relation hasn't been touched at all in our query.
* We need to acquire lock on it before we try to do anything with it.
* (The subsequent recursive call of RewriteQuery will suppose that we
* already have the right lock!) Since it will become the query target
* relation, RowExclusiveLock is always the right thing.
*/
base_rel = heap_open(base_rte->relid, RowExclusiveLock);
* While we have the relation open, update the RTE's relkind, just in case
* it changed since this view was made (cf. AcquireRewriteLocks).
*/
base_rte->relkind = base_rel->rd_rel->relkind;
heap_close(base_rel, NoLock);
* If the view query contains any sublink subqueries then we need to also
* acquire locks on any relations they refer to. We know that there won't
* be any subqueries in the range table or CTEs, so we can skip those, as
* in AcquireRewriteLocks.
*/
if (viewquery->hasSubLinks) {
(void)query_tree_walker(viewquery, (bool (*)())acquireLocksOnSubLinks, NULL, QTW_IGNORE_RC_SUBQUERIES);
}
* Create a new target RTE describing the base relation, and add it to the
* outer query's rangetable. (What's happening in the next few steps is
* very much like what the planner would do to "pull up" the view into the
* outer query. Perhaps someday we should refactor things enough so that
* we can share code with the planner.)
*
* We will not do so if basic relation of view is already exist in rtables,
* cause multiple-relation modifying include views is allowed.
*/
SetNewRteIfExistContext setContext;
setContext.parsetree = parsetree;
setContext.baseRelid = base_rte->relid;
setContext.resultRelation = resultRelation;
setContext.newRte = new_rte;
setContext.newRtIndex = newRtIndex;
if (!SetNewRteIfExist(&setContext)) {
*new_rte = base_rte;
parsetree->rtable = lappend(parsetree->rtable, *new_rte);
*newRtIndex = list_length(parsetree->rtable);
}
} else if (base_rte->rtekind == RTE_SUBQUERY) {
*new_rte = base_rte;
parsetree->rtable = lappend(parsetree->rtable, *new_rte);
*newRtIndex = list_length(parsetree->rtable);
}
*out_base_rte = base_rte;
}
static bool NewRteForRewriteTargetView_walker(Node* node, NewRteForRewriteTargetViewContext* context)
{
if (node == NULL) {
return false;
}
Query* viewquery = context->viewquery;
int newRtIndex = 0;
int baseRtIndex = 0;
Relation view = context->view;
RangeTblEntry* view_rte = context->view_rte;
if (IsA(node, RangeTblRef)) {
RangeTblRef* rtr = (RangeTblRef*)node;
RangeTblEntry* base_rte = NULL;
RangeTblEntry* new_rte = NULL;
List* view_targetlist = viewquery->targetList;
baseRtIndex = rtr->rtindex;
if (bms_is_member(baseRtIndex, context->visited_rtes)) {
return false;
}
context->visited_rtes = bms_add_member(context->visited_rtes, rtr->rtindex);
GetNewRte(context, rtr, &base_rte, &new_rte, &newRtIndex);
* Adjust the view's targetlist Vars to reference the new target RTE, ie
* make their varnos be newRtIndex instead of baseRtIndex. There can
* be no Vars for other rels in the tlist, so this is sufficient to pull
* up the tlist expressions for use in the outer query. The tlist will
* provide the replacement expressions used by ReplaceVarsFromTargetList
* below.
*/
context->newIndexes[baseRtIndex] = newRtIndex;
if (!bms_is_member(baseRtIndex, context->base_indexes)) {
context->base_indexes = bms_add_member(context->base_indexes, baseRtIndex);
}
if (base_rte->rtekind == RTE_RELATION) {
* Mark the new target RTE for the permissions checks that we want to
* enforce against the view owner, as distinct from the query caller. At
* the relation level, require the same INSERT/UPDATE/DELETE permissions
* that the query caller needs against the view. We drop the ACL_SELECT
* bit that is presumably in new_rte->requiredPerms initially.
*
* Note: the original view RTE remains in the query's rangetable list.
* Although it will be unused in the query plan, we need it there so that
* the executor still performs appropriate permissions checks for the
* query caller's use of the view.
*/
new_rte->checkAsUser = view->rd_rel->relowner;
new_rte->requiredPerms = view_rte->requiredPerms;
* Now for the per-column permissions bits.
*
* Initially, new_rte contains selectedCols permission check bits for all
* base-rel columns referenced by the view, but since the view is a SELECT
* query its modifiedCols is empty. We set modifiedCols to include all
* the columns the outer query is trying to modify, adjusting the column
* numbers as needed. But we leave selectedCols as-is, so the view owner
* must have read permission for all columns used in the view definition,
* even if some of them are not read by the outer query. We could try to
* limit selectedCols to only columns used in the transformed query, but
* that does not correspond to what happens in ordinary SELECT usage of a
* view: all referenced columns must have read permission, even if
* optimization finds that some of them can be discarded during query
* transformation. The flattening we're doing here is an optional
* optimization, too. (If you are unpersuaded and want to change this,
* note that applying adjust_view_column_set to view_rte->selectedCols is
* clearly *not* the right answer, since that neglects base-rel columns
* used in the view's WHERE quals.)
*
* This step needs the modified view targetlist, so we have to do things
* in this order.
*/
new_rte->insertedCols = bms_add_members(new_rte->insertedCols,
adjust_view_column_set(view_rte->insertedCols, view_targetlist));
new_rte->updatedCols = bms_add_members(new_rte->updatedCols,
adjust_view_column_set(view_rte->updatedCols, view_targetlist));
new_rte->modifiedCols = bms_union(new_rte->insertedCols, new_rte->updatedCols);
* Move any security barrier quals from the view RTE onto the new target
* RTE. Any such quals should now apply to the new target RTE and will not
* reference the original view RTE in the rewritten query.
*/
new_rte->securityQuals = list_concat(new_rte->securityQuals, view_rte->securityQuals);
}
return false;
}
return expression_tree_walker(node, (bool (*)())NewRteForRewriteTargetView_walker, (void*)context);
}
static bool IsEqualsOperator(int operid)
{
bool result = false;
CatCList* catlist = NULL;
int i;
* Search pg_amop to see if the operid is registered as the "="
*/
catlist = SearchSysCacheList1(AMOPOPID, ObjectIdGetDatum(operid));
for (i = 0; i < catlist->n_members; i++) {
HeapTuple tuple = t_thrd.lsc_cxt.FetchTupleFromCatCList(catlist, i);
Form_pg_amop aform = (Form_pg_amop)GETSTRUCT(tuple);
if (aform->amopstrategy == BTEqualStrategyNumber) {
result = true;
break;
}
}
ReleaseSysCacheList(catlist);
return result;
}
* FindTargetTable
* Find the possible key preserved table for a view, compare two tables at a time.
* The way of determining the key preserved table is basically the same as the way
* that function find_non_keypreservered_rels does, except that here we need to consider the
* possibility that one of the candidate rte is a subquery. A subquery cannnot be a key
* preserved table. If one of the two candidate table is a subquery and the other is not
* and the other has one or more unique/primary keys, the other is also a possible key preserved
* key. If neither of them is a subquery, the determine the key preserved table the same way
* as find_non_kaypreserved_rels does.
*/
struct FindTargetTableContext {
int rRtIndex;
int lRtIndex;
List* rtable;
bool rIsKey;
bool lIsKey;
};
static void FindKeyInRel(Relation rel, Var* var, FindTargetTableContext* context);
static bool FindKeyInView(Relation rel, Var* var, FindTargetTableContext* context);
static bool FindTargetTableWalker(Node* node, FindTargetTableContext* context)
{
if (node == NULL) {
return false;
}
if (context == NULL) {
return true;
}
int rRtIndex = context->rRtIndex;
int lRtIndex = context->lRtIndex;
List* rtable = context->rtable;
if (IsA(node, Var)) {
Var* var = (Var*)node;
RangeTblEntry* rte = NULL;
rte = var->varno == rRtIndex? rt_fetch(rRtIndex, rtable) :
var->varno == lRtIndex? rt_fetch(lRtIndex, rtable) : NULL;
if (rte != NULL) {
if (rte->rtekind == RTE_SUBQUERY) {
return false;
}
Relation rel = relation_open(rte->relid, AccessShareLock);
if (rel->rd_rel->relkind == RELKIND_VIEW) {
bool res = FindKeyInView(rel, var, context);
relation_close(rel, AccessShareLock);
return res;
}
if (!RelationGetForm(rel)->relhasindex) {
relation_close(rel, AccessShareLock);
return false;
}
FindKeyInRel(rel, var, context);
relation_close(rel, AccessShareLock);
return false;
}
} else if (IsA(node, OpExpr)) {
OpExpr* op = (OpExpr*)node;
Oid opno = op->opno;
const int opArgNum = 2;
if (list_length(op->args) != opArgNum || !IsEqualsOperator(opno)) {
return true;
}
}
return expression_tree_walker(node, (bool (*)())FindTargetTableWalker, (void*)context);
}
static void FindKeyInRel(Relation rel, Var* var, FindTargetTableContext* context)
{
int rRtIndex = context->rRtIndex;
List* indexoidlist = RelationGetIndexList(rel);
Oid relpkindex = rel->rd_pkindex;
ListCell* indexoidscan = NULL;
if (indexoidlist == NIL) {
relation_close(rel, AccessShareLock);
return;
}
foreach (indexoidscan, indexoidlist) {
Oid indexoid = lfirst_oid(indexoidscan);
Relation indexDesc = index_open(indexoid, AccessShareLock);
IndexInfo* indexInfo = BuildIndexInfo(indexDesc);
bool isPk = (indexoid == relpkindex);
bool isKey = indexInfo->ii_Unique && indexInfo->ii_Expressions == NIL && indexInfo->ii_Predicate == NIL;
int i = 0;
if (!isPk && !isKey) {
index_close(indexDesc, AccessShareLock);
continue;
}
for (i = 0; i < indexInfo->ii_NumIndexAttrs; i++) {
int attnum = indexInfo->ii_KeyAttrNumbers[i];
if (attnum == var->varattno) {
if (var->varno == rRtIndex)
context->rIsKey = (isPk || (isKey && i < indexInfo->ii_NumIndexKeyAttrs));
else
context->lIsKey = (isPk || (isKey && i < indexInfo->ii_NumIndexKeyAttrs));
}
break;
}
if (i < indexInfo->ii_NumIndexAttrs) {
index_close(indexDesc, AccessShareLock);
break;
}
}
}
static bool FindKeyInView(Relation rel, Var* var, FindTargetTableContext* context)
{
Query* subviewqry = (Query*)copyObject(get_view_query(rel));
ListCell* fcell = NULL;
FromExpr* f = subviewqry->jointree;
List* rtable = subviewqry->rtable;
int newRtIndex = 0;
bool allHaveKey = true;
if (list_length(f->fromlist) == 1) {
newRtIndex = GetNewResultRelation((Node*)linitial(f->fromlist), rtable);
FindTargetTableContext subcontext = {newRtIndex, newRtIndex, rtable, false, false};
if (!expression_tree_walker((Node*)(subviewqry->targetList),
(bool (*)())FindTargetTableWalker,
(void*)(&subcontext))) {
if (!subcontext.rIsKey) {
pfree(subviewqry);
return false;
}
}
}
foreach (fcell, f->fromlist) {
int tmp_rt_index = GetNewResultRelation((Node*)lfirst(fcell), rtable);
if (newRtIndex == 0) {
newRtIndex = tmp_rt_index;
continue;
} else if (newRtIndex == -1) {
break;
} else if (newRtIndex != tmp_rt_index) {
FindTargetTableContext subcontext = {tmp_rt_index, newRtIndex, rtable, false, false};
if (!expression_tree_walker((Node*)(f->quals),
(bool (*)())FindTargetTableWalker,
(void*)(&subcontext))) {
newRtIndex = subcontext.rIsKey ? newRtIndex :
subcontext.lIsKey ? tmp_rt_index : -1;
allHaveKey = subcontext.rIsKey && subcontext.lIsKey && allHaveKey;
} else {
newRtIndex = -1;
}
}
}
if (newRtIndex == -1) {
return true;
} else if (allHaveKey) {
context->rIsKey = var->varno == context->rRtIndex ? true : context->rIsKey;
context->lIsKey = var->varno == context->lRtIndex ? true : context->lIsKey;
}
pfree(subviewqry);
return false;
}
* GetNewResultRelation
* Find the result relation for deletes on a view from the view's jointree,
* rtable is the list that the rtr(s) on the jointree reference.
* The rte for delete should be the view's key preserved rel, whose unique key or primary key is
* also a unique key or a primary key for the view.
*/
static int ProcessFromExprForNewRel(FromExpr* f, List* rtable)
{
int newRtIndex = 0;
ListCell* cell = NULL;
foreach (cell, f->fromlist) {
int tmp_rt_index = GetNewResultRelation((Node*)lfirst(cell), rtable);
if (newRtIndex == 0) {
newRtIndex = tmp_rt_index;
continue;
} else if (newRtIndex == -1) {
break;
} else if (newRtIndex != tmp_rt_index) {
FindTargetTableContext context;
context.rRtIndex = tmp_rt_index;
context.lRtIndex = newRtIndex;
context.rtable = rtable;
context.rIsKey = false;
context.lIsKey = false;
if (!expression_tree_walker((Node*)(f->quals),
(bool (*)())FindTargetTableWalker,
(void*)(&context))) {
newRtIndex = context.rIsKey ? newRtIndex :
context.lIsKey ? tmp_rt_index : -1;
} else {
newRtIndex = -1;
}
}
}
return newRtIndex;
}
static int ProcessJoinExprForNewRel(JoinExpr* j, List* rtable)
{
int newRtIndex = 0;
switch (j->jointype) {
case JOIN_LEFT:
newRtIndex = GetNewResultRelation(j->larg, rtable);
break;
case JOIN_RIGHT:
newRtIndex = GetNewResultRelation(j->rarg, rtable);
break;
case JOIN_INNER: {
if (j->quals == NULL) {
newRtIndex = -1;
}
int rRtIndex = GetNewResultRelation(j->rarg, rtable);
int lRtIndex = GetNewResultRelation(j->larg, rtable);
if (rRtIndex < 0 || lRtIndex < 0) {
newRtIndex = -1;
break;
}
FindTargetTableContext context;
context.rRtIndex = rRtIndex;
context.lRtIndex = lRtIndex;
context.rtable = rtable;
context.rIsKey = false;
context.lIsKey = false;
if (!expression_tree_walker((Node*)(j->quals),
(bool (*)())FindTargetTableWalker,
(void*)(&context))) {
newRtIndex = context.rIsKey ? lRtIndex :
context.lIsKey ? rRtIndex : -1;
} else {
newRtIndex = -1;
}
break;
}
case JOIN_FULL :
return -1;
default: break;
}
return newRtIndex;
}
static int GetNewResultRelation(Node* node, List* rtable)
{
if (node==NULL) {
return -1;
}
int newRtIndex = 0;
switch (nodeTag(node)) {
case T_FromExpr: {
FromExpr* f = (FromExpr*)node;
newRtIndex = ProcessFromExprForNewRel(f, rtable);
break;
}
case T_JoinExpr: {
JoinExpr* j = (JoinExpr*)node;
newRtIndex = ProcessJoinExprForNewRel(j, rtable);
break;
}
case T_RangeTblRef: {
RangeTblRef* rtr = (RangeTblRef*)node;
newRtIndex = rtr->rtindex;
break;
}
default:
ereport(ERROR,
(errcode(ERRCODE_UNRECOGNIZED_NODE_TYPE),
errmsg("unrecognized node type: %d", (int) nodeTag(node))));
break;
}
return newRtIndex;
}
static int FindBaseRteForInsertOrUpdate(List* parse_targetlist, List* view_targetlist, int resultRelation)
{
ListCell* targetCell = NULL;
int baseRtIndex = 0;
foreach (targetCell, parse_targetlist) {
TargetEntry* tle = (TargetEntry*)lfirst(targetCell);
if (tle->resjunk || (tle->rtindex != resultRelation && tle->rtindex != 0 &&
u_sess->attr.attr_sql.sql_compatibility == B_FORMAT))
continue;
TargetEntry* view_tle = get_tle_by_resno(view_targetlist, tle->resno);
Var* var = NULL;
var = (Var*)(view_tle->expr);
if (!IsA(var, Var))
ereport(ERROR,
(errmsg("cannot update or delete on generated columns")));
if (baseRtIndex == 0) {
baseRtIndex = var->varno;
} else if (baseRtIndex != var->varno && strcmp(tle->resname, "wholerow") != 0 &&
!(u_sess->attr.attr_sql.sql_compatibility == B_FORMAT)) {
ereport(ERROR,
(errmsg("cannot update or delete columns from different base tables at the same time")));
}
* For INSERT/UPDATE we must also update resnos in the targetlist to refer
* to columns of the base relation, since those indicate the target
* columns to be affected.
*
* Note that this destroys the resno ordering of the targetlist, but that
* will be fixed when we recurse through rewriteQuery, which will invoke
* rewriteTargetListIU again on the updated targetlist.
*/
if (view_tle != NULL && !view_tle->resjunk && IsA(view_tle->expr, Var))
tle->resno = ((Var*)view_tle->expr)->varattno;
else
ereport(ERROR, (errmsg("attribute number %d not found in view targetlist", tle->resno)));
}
return baseRtIndex;
}
int ReplaceResultTargetEntry(Query* parsetree, Query* viewquery, List* rtables, int resultRelation)
{
int baseRtIndex = 0;
int newRtIndex = 0;
Oid base_relid;
RangeTblEntry* base_rte = NULL;
List* parse_targetlist = parsetree->targetList;
List* view_targetlist = viewquery->targetList;
if (parsetree->commandType == CMD_DELETE) {
baseRtIndex = GetNewResultRelation((Node*)(viewquery->jointree), rtables);
if (baseRtIndex < 1) {
ereport(ERROR,
(errmsg("cannot determine an exact row for the view to update or delete")));
}
} else if (parsetree->commandType == CMD_UPDATE || parsetree->commandType == CMD_INSERT) {
baseRtIndex = FindBaseRteForInsertOrUpdate(parse_targetlist, view_targetlist, resultRelation);
}
base_rte = rt_fetch(baseRtIndex, rtables);
if (base_rte->rtekind == RTE_SUBQUERY && u_sess->attr.attr_sql.sql_compatibility == B_FORMAT) {
ereport(ERROR,
(errmsg("update/delete on a table in a view's subquery is not supported in B-format database")));
}
base_relid = base_rte->relid;
ListCell* rtcell = list_head(parsetree->rtable);
int rtindex = 1;
while (rtcell) {
RangeTblEntry* rte = (RangeTblEntry*)lfirst(rtcell);
if (base_relid == rte->relid && rtindex != resultRelation) {
newRtIndex = rtindex;
break;
}
rtcell = lnext(rtcell);
rtindex++;
}
if (newRtIndex == 0) {
ereport(ERROR,
(errmsg("cannot determine an exact row for the view to update or delete")));
}
return newRtIndex;
}
static void RecurseChangeVarNodes(Query* parsetree, Query* viewquery,
Bitmapset** base_indexes, int* newIndexes, int baseIndex)
{
if (!bms_is_member(baseIndex, *base_indexes)) {
return;
}
int newIndex = newIndexes[baseIndex];
if (newIndex == baseIndex) {
*base_indexes = bms_del_member(*base_indexes, baseIndex);
return;
}
* corresponding to new_rt_index is processed */
RecurseChangeVarNodes(parsetree, viewquery, base_indexes, newIndexes, newIndex);
ChangeVarNodes((Node*)viewquery->targetList, baseIndex, newIndex, 0);
ChangeVarNodes((Node*)viewquery->jointree, baseIndex, newIndex, 0);
*base_indexes = bms_del_member(*base_indexes, baseIndex);
}
* rewriteTargetView -
* Attempt to rewrite a query where the target relation is a view, so that
* the view's base relation becomes the target relation.
*
* Note that the base relation here may itself be a view, which may or may not
* have INSTEAD OF triggers or rules to handle the update. That is handled by
* the recursion in RewriteQuery.
*
* For multiple modifying, result_relation is needed to indicate which modified
* view to rewrite.
*/
static Query* rewriteTargetView(Query *parsetree, Relation view, int result_relation)
{
Query* viewquery = NULL;
const char* auto_update_detail = NULL;
int base_rt_index;
int new_rt_index;
RangeTblEntry* view_rte = NULL;
List* view_targetlist = NIL;
ListCell* lc = NULL;
ListCell* rtcell = NULL;
* Get the Query from the view's ON SELECT rule. We're going to munge the
* Query to change the view's base relation into the target relation,
* along with various other changes along the way, so we need to make a
* copy of it (get_view_query() returns a pointer into the relcache, so we
* have to treat it as read-only).
*/
viewquery = (Query*)copyObject(get_view_query(view));
PlannerInfo* root = makeNode(PlannerInfo);
root->parse = viewquery;
foreach (rtcell, viewquery->rtable) {
RangeTblEntry* rte = (RangeTblEntry*)lfirst(rtcell);
if (rte->rtekind == RTE_JOIN && IS_OUTER_JOIN(rte->jointype)) {
reduce_outer_joins(root);
break;
}
}
List* base_targetList = list_copy(viewquery->targetList);
ListCell* base_cell;
ListCell* new_cell;
viewquery->targetList = (List*)flatten_join_alias_vars(root, (Node*)(viewquery->targetList));
viewquery->jointree = (FromExpr*)flatten_join_alias_vars(root, (Node*)(viewquery->jointree));
forboth(base_cell, base_targetList, new_cell, viewquery->targetList) {
TargetEntry* base_tle = (TargetEntry*)lfirst(base_cell);
TargetEntry* new_tle = (TargetEntry*)lfirst(new_cell);
Index base_index = ((Var*)(base_tle->expr))->varno;
Index new_index = ((Var*)(new_tle->expr))->varno;
if (base_index != new_index)
ChangeVarNodes((Node*)viewquery, base_index, new_index, 0);
}
list_free(base_targetList);
auto_update_detail = view_query_is_auto_updatable(viewquery, parsetree->commandType != CMD_DELETE, false);
do {
if (parsetree->commandType == CMD_INSERT) {
if (list_length(viewquery->jointree->fromlist) != 1) {
auto_update_detail = gettext_noop(
"Views that do not select from a single table or view are not automatically updatable.");
break;
}
RangeTblRef* rtr = (RangeTblRef*)linitial(viewquery->jointree->fromlist);
if (!IsA(rtr, RangeTblRef)) {
auto_update_detail = gettext_noop(
"Views that do not select from a single table or view are not automatically updatable.");
break;
}
RangeTblEntry* rte = rt_fetch(rtr->rtindex, viewquery->rtable);
if (rte->rtekind != RTE_RELATION || (rte->relkind != RELKIND_RELATION &&
rte->relkind != RELKIND_FOREIGN_TABLE && rte->relkind != RELKIND_VIEW)) {
auto_update_detail = gettext_noop(
"Views that do not select from a single table or view are not automatically updatable.");
break;
}
}
} while (0);
if (auto_update_detail) {
switch (parsetree->commandType) {
case CMD_INSERT:
ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot insert into view \"%s\"", RelationGetRelationName(view)),
errdetail_internal("%s", _(auto_update_detail)),
errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger or "
"an unconditional ON INSERT DO INSTEAD rule.")));
break;
case CMD_UPDATE:
ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot update view \"%s\"", RelationGetRelationName(view)),
errdetail_internal("%s", _(auto_update_detail)),
errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger or "
"an unconditional ON UPDATE DO INSTEAD rule.")));
break;
case CMD_DELETE:
ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot delete from view \"%s\"", RelationGetRelationName(view)),
errdetail_internal("%s", _(auto_update_detail)),
errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger or "
"an unconditional ON DELETE DO INSTEAD rule.")));
break;
default:
ereport(ERROR, (errmsg("unrecognized CmdType: %d", (int)parsetree->commandType)));
break;
}
}
if (unlikely(RESTRICT_NONSYSTEM_RELATION_KIND_VIEW && RelationGetRelid(view) >= FirstNormalObjectId)) {
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("Access to non-system view \"%s\" is restricted.", RelationGetRelationName(view)),
errcause("Access to non-system view \"%s\" is restricted.", RelationGetRelationName(view)),
erraction("Check the value of restrict_nonsystem_relation_kind.")));
}
* For INSERT/UPDATE the modified columns must all be updatable. Note that
* we get the modified columns from the query's targetlist, not from the
* result RTE's modifiedCols set, since rewriteTargetListIU may have added
* additional targetlist entries for view defaults, and these must also be
* updatable.
*/
if (parsetree->commandType != CMD_DELETE) {
Bitmapset *modified_cols = NULL;
char* nonUpdatableCol = NULL;
foreach (lc, parsetree->targetList) {
TargetEntry* tle = (TargetEntry*)lfirst(lc);
if ((tle->rtindex == 0 || tle->rtindex == (Index)result_relation) && !tle->resjunk)
modified_cols = bms_add_member(modified_cols, tle->resno - FirstLowInvalidHeapAttributeNumber);
}
auto_update_detail = view_cols_are_auto_updatable(viewquery, modified_cols, NULL, &nonUpdatableCol);
if (auto_update_detail) {
* This is a different error, caused by an attempt to update a
* non-updatable column in an otherwise updatable view.
*/
switch (parsetree->commandType) {
case CMD_INSERT:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot insert into column \"%s\" of view \"%s\"", nonUpdatableCol,
RelationGetRelationName(view)),
errdetail_internal("%s", _(auto_update_detail))));
break;
case CMD_UPDATE:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot update column \"%s\" of view \"%s\"", nonUpdatableCol,
RelationGetRelationName(view)),
errdetail_internal("%s", _(auto_update_detail))));
break;
default:
elog(ERROR, "unrecognized CmdType: %d", (int)parsetree->commandType);
break;
}
}
}
rtcell = list_head(parsetree->rtable);
ListCell* prev_cell = NULL;
while (rtcell) {
RangeTblEntry* rte = (RangeTblEntry*)lfirst(rtcell);
if (rte->rtekind == RTE_JOIN) {
parsetree->rtable = list_delete_ptr(parsetree->rtable, rte);
rtcell = prev_cell == NULL? list_head(parsetree->rtable) : lnext(prev_cell);
continue;
}
prev_cell = rtcell;
rtcell = lnext(rtcell);
}
view_rte = rt_fetch(result_relation, parsetree->rtable);
NewRteForRewriteTargetViewContext rteContext;
rteContext.viewquery = viewquery;
rteContext.parsetree = parsetree;
rteContext.resultRelation = result_relation;
rteContext.view = view;
rteContext.view_rte = view_rte;
int size = (list_length(viewquery->rtable) + 1) * sizeof(int);
rteContext.newIndexes = static_cast<int*>(palloc(size));
errno_t rc = memset_s(rteContext.newIndexes, size, 0, size);
securec_check(rc, "\0", "\0");
rteContext.visited_rtes = NULL;
rteContext.base_indexes = NULL;
expression_tree_walker((Node*)viewquery->jointree->fromlist,
(bool (*)())NewRteForRewriteTargetView_walker,
(void*)(&rteContext));
int i = 3;
while (!bms_is_empty(rteContext.base_indexes)) {
RecurseChangeVarNodes(parsetree, viewquery, &(rteContext.base_indexes), rteContext.newIndexes, i);
i++;
}
if (parsetree->commandType != CMD_INSERT)
parsetree->jointree->fromlist = list_concat(parsetree->jointree->fromlist, viewquery->jointree->fromlist);
view_targetlist = viewquery->targetList;
view_rte->securityQuals = NIL;
bms_free(rteContext.visited_rtes);
pfree(rteContext.newIndexes);
* For UPDATE/DELETE, rewriteTargetListUD will have added a wholerow junk
* TLE for the view to the end of the targetlist, which we no longer need.
* Remove it to avoid unnecessary work when we process the targetlist.
* Note that when we recurse through rewriteQuery a new junk TLE will be
* added to allow the executor to find the proper row in the new target
* relation. (So, if we failed to do this, we might have multiple junk
* TLEs with the same name, which would be disastrous.)
*/
if (parsetree->commandType != CMD_INSERT) {
ListCell* res = NULL;
TargetEntry* tle = NULL;
foreach (res, parsetree->targetList) {
tle = (TargetEntry*)lfirst(res);
if (tle->rtindex == (Index)result_relation && strcmp(tle->resname, "wholerow") == 0) {
parsetree->targetList = list_delete_ptr(parsetree->targetList, tle);
break;
}
}
}
* Now update all Vars in the outer query that reference the view to
* reference the appropriate column of the base relation instead.
*/
parsetree = (Query*)ReplaceVarsFromTargetList((Node*)parsetree,
result_relation,
0,
view_rte,
view_targetlist,
REPLACEVARS_REPORT_ERROR,
0,
&parsetree->hasSubLinks);
* Update all other RTI references in the query that point to the view
* (for example, parsetree->resultRelation itself) to point to the new
* base relation instead. Vars will not be affected since none of them
* reference parsetree->resultRelation any longer.
*/
if (parsetree->commandType != CMD_INSERT) {
ListCell* fc = NULL;
List* temp = parsetree->jointree->fromlist;
parsetree->jointree->fromlist = NIL;
foreach (fc, temp) {
Node* node = (Node*)lfirst(fc);
if (!IsA(node, RangeTblRef) || ((RangeTblRef*)node)->rtindex != result_relation) {
parsetree->jointree->fromlist = lappend(parsetree->jointree->fromlist, node);
}
}
list_free(temp);
}
base_rt_index = result_relation;
new_rt_index = ReplaceResultTargetEntry(parsetree, viewquery, parsetree->rtable, result_relation);
ChangeVarNodes((Node*)(parsetree), result_relation, new_rt_index, 0);
* For UPDATE/DELETE, pull up any WHERE quals from the view. We know that
* any Vars in the quals must reference the one base relation, so we need
* only adjust their varnos to reference the new target (just the same as
* we did with the view targetlist).
*
* Note that there is special-case handling for the quals of a security
* barrier view, since they need to be kept separate from any user-supplied
* quals, so these quals are kept on the new target RTE.
* For INSERT, the view's quals can be ignored in the main query.
*/
if (parsetree->commandType != CMD_INSERT) {
Node* viewqual = (Node*)viewquery->jointree->quals;
if (RelationIsSecurityView(view) && viewqual != NULL) {
* Note: the parsetree has been mutated, so the new_rte pointer is
* stale and needs to be re-computed.
*/
RangeTblEntry* new_rte = rt_fetch(new_rt_index, parsetree->rtable);
new_rte->securityQuals = lcons(viewqual, new_rte->securityQuals);
* Make sure that the query is marked correctly if the added qual
* has sublinks.
*/
if (!parsetree->hasSubLinks)
parsetree->hasSubLinks = checkExprHasSubLink(viewqual);
} else
AddQual(parsetree, (Node*)viewqual);
}
* For INSERT/UPDATE, if the view has the WITH CHECK OPTION, or any parent
* view specified WITH CASCADED CHECK OPTION, add the quals from the view
* to the query's withCheckOptions list.
*/
if (parsetree->commandType != CMD_DELETE) {
bool has_wco = RelationHasCheckOption(view);
bool cascaded = RelationHasCascadedCheckOption(view);
* If the parent view has a cascaded check option, treat this view as
* if it also had a cascaded check option.
*
* New WithCheckOptions are added to the start of the list, so if there
* is a cascaded check option, it will be the first item in the list.
*/
if (parsetree->withCheckOptions != NIL) {
WithCheckOption* parent_wco = (WithCheckOption*)linitial(parsetree->withCheckOptions);
if (parent_wco->cascaded) {
has_wco = true;
cascaded = true;
}
}
* Add the new WithCheckOption to the start of the list, so that
* checks on inner views are run before checks on outer views, as
* required by the SQL standard.
*
* If the new check is CASCADED, we need to add it even if this view
* has no quals, since there may be quals on child views. A LOCAL
* check can be omitted if this view has no quals.
*/
if (has_wco && (cascaded || viewquery->jointree->quals != NULL)) {
WithCheckOption* wco = makeNode(WithCheckOption);
wco->viewname = pstrdup(RelationGetRelationName(view));
wco->qual = NULL;
wco->cascaded = cascaded;
wco->rtindex = new_rt_index;
parsetree->withCheckOptions = lcons(wco, parsetree->withCheckOptions);
if (viewquery->jointree->quals != NULL) {
wco->qual = (Node*)viewquery->jointree->quals;
ChangeVarNodes(wco->qual, base_rt_index, new_rt_index, 0);
* Make sure that the query is marked correctly if the added
* qual has sublinks. We can skip this check if the query is
* already marked, or if the command is an UPDATE, in which
* case the same qual will have already been added, and this
* check will already have been done.
*/
if (!parsetree->hasSubLinks &&
parsetree->commandType != CMD_UPDATE)
parsetree->hasSubLinks = checkExprHasSubLink(wco->qual);
}
}
}
return parsetree;
}
void ereport_for_each_cmdtype(CmdType event, Relation rt_entry_relation)
{
switch (event) {
case CMD_INSERT:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot perform INSERT RETURNING on relation \"%s\"",
RelationGetRelationName(rt_entry_relation)),
errhint("You need an unconditional ON INSERT DO INSTEAD rule with a RETURNING clause.")));
break;
case CMD_UPDATE:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot perform UPDATE RETURNING on relation \"%s\"",
RelationGetRelationName(rt_entry_relation)),
errhint("You need an unconditional ON UPDATE DO INSTEAD rule with a RETURNING clause.")));
break;
case CMD_DELETE:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot perform DELETE RETURNING on relation \"%s\"",
RelationGetRelationName(rt_entry_relation)),
errhint("You need an unconditional ON DELETE DO INSTEAD rule with a RETURNING clause.")));
break;
default: {
ereport(
ERROR, (errcode(ERRCODE_UNEXPECTED_NODE_STATE), errmsg("unrecognized commandType: %d", (int)event)));
} break;
}
}
* RewriteQuery -
* rewrites the query and apply the rules again on the queries rewritten
*
* rewrite_events is a list of open query-rewrite actions, so we can detect
* infinite recursion.
*/
List* RewriteQuery(Query* parsetree, List* rewrite_events)
{
CmdType event = parsetree->commandType;
bool instead = false;
bool returning = false;
Query* qual_product = NULL;
List* rewritten = NIL;
ListCell* lc1 = NULL;
#ifdef PGXC
List* parsetree_list = NIL;
List* qual_product_list = NIL;
ListCell* pt_cell = NULL;
#endif
* First, recursively process any insert/update/delete statements in WITH
* clauses. (We have to do this first because the WITH clauses may get
* copied into rule actions below.)
*/
foreach (lc1, parsetree->cteList) {
CommonTableExpr* cte = (CommonTableExpr*)lfirst(lc1);
Query* ctequery = (Query*)cte->ctequery;
List* newstuff = NIL;
AssertEreport(IsA(ctequery, Query), MOD_OPT, "");
if (ctequery->commandType == CMD_SELECT)
continue;
newstuff = RewriteQuery(ctequery, rewrite_events);
* Currently we can only handle unconditional, single-statement DO
* INSTEAD rules correctly; we have to get exactly one Query out of
* the rewrite operation to stuff back into the CTE node.
*/
if (list_length(newstuff) == 1) {
ctequery = (Query*)linitial(newstuff);
AssertEreport(IsA(ctequery, Query), MOD_OPT, "");
AssertEreport(!ctequery->canSetTag, MOD_OPT, "");
cte->ctequery = (Node*)ctequery;
} else if (newstuff == NIL) {
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("DO INSTEAD NOTHING rules are not supported for data-modifying statements in WITH")));
} else {
ListCell* lc2 = NULL;
foreach (lc2, newstuff) {
Query* q = (Query*)lfirst(lc2);
if (q->querySource == QSRC_QUAL_INSTEAD_RULE)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("conditional DO INSTEAD rules are not supported for data-modifying statements in "
"WITH")));
if (q->querySource == QSRC_NON_INSTEAD_RULE)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("DO ALSO rules are not supported for data-modifying statements in WITH")));
}
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg(
"multi-statement DO INSTEAD rules are not supported for data-modifying statements in WITH")));
}
}
* If the statement is an insert, update, or delete, adjust its targetlist
* as needed, and then fire INSERT/UPDATE/DELETE rules on it.
*
* SELECT rules are handled later when we have all the queries that should
* get executed. Also, utilities aren't rewritten at all (do we still
* need that check?)
*/
if (event != CMD_SELECT && event != CMD_UTILITY) {
int result_relation;
RangeTblEntry* rt_entry = NULL;
Relation rt_entry_relation;
List* locks = NIL;
bool hasGenCol = false;
List* product_queries = NIL;
List* attrnos = NIL;
int values_rte_index = 0;
bool defaults_remaining = false;
ListCell* resultRel = NULL;
bool rewriteView = false;
List* rewriteRelations = NIL;
result_relation = linitial2_int(parsetree->resultRelations);
if (result_relation == 0)
return rewritten;
rt_entry = rt_fetch(result_relation, parsetree->rtable);
if (rt_entry->rtekind == RTE_SUBQUERY) {
rewritten = lappend(rewritten, parsetree);
return rewritten;
}
AssertEreport(rt_entry->rtekind == RTE_RELATION, MOD_OPT, "");
* We can use NoLock here since either the parser or
* AcquireRewriteLocks should have locked the rel already.
*/
rt_entry_relation = heap_open(rt_entry->relid, NoLock);
* Rewrite the targetlist as needed for the command type.
*/
if (event == CMD_INSERT) {
RangeTblEntry* values_rte = NULL;
* If it's an INSERT ... VALUES (...), (...), ... there will be a
* single RTE for the VALUES targetlists.
*/
if (list_length(parsetree->jointree->fromlist) == 1) {
RangeTblRef* rtr = (RangeTblRef*)linitial(parsetree->jointree->fromlist);
if (IsA(rtr, RangeTblRef)) {
RangeTblEntry* rte = rt_fetch(rtr->rtindex, parsetree->rtable);
if (rte->rtekind == RTE_VALUES) {
values_rte = rte;
values_rte_index = rtr->rtindex;
}
}
}
if (values_rte != NULL) {
parsetree->targetList =
rewriteTargetListIU(parsetree->targetList, parsetree->commandType,
rt_entry_relation, result_relation, &attrnos,
&hasGenCol);
checkGenDefault(values_rte, rt_entry_relation, attrnos, hasGenCol);
if (!rewriteValuesRTE(parsetree, values_rte, rt_entry_relation, attrnos, false)) {
defaults_remaining = true;
}
} else {
parsetree->targetList =
rewriteTargetListIU(parsetree->targetList, parsetree->commandType,
rt_entry_relation, result_relation, NULL,
&hasGenCol);
}
if (parsetree->upsertClause != NULL &&
parsetree->upsertClause->upsertAction == UPSERT_UPDATE) {
parsetree->upsertClause->updateTlist =
rewriteTargetListIU(parsetree->upsertClause->updateTlist, CMD_UPDATE,
rt_entry_relation, result_relation, NULL,
&hasGenCol);
}
} else if (event == CMD_UPDATE) {
if (list_length(parsetree->resultRelations) > 1) {
rewriteTargetListMutilUpdate(parsetree, parsetree->rtable, parsetree->resultRelations);
multiUpdateSetExtraUpdatedCols(parsetree);
} else {
parsetree->targetList =
rewriteTargetListIU(parsetree->targetList, parsetree->commandType,
rt_entry_relation, result_relation, NULL,
&hasGenCol);
setExtraUpdatedCols(rt_entry, rt_entry_relation->rd_att);
rewriteTargetListUD(parsetree, rt_entry, rt_entry_relation, result_relation);
}
} else if (event == CMD_DELETE) {
if (list_length(parsetree->resultRelations) > 1) {
rewriteTargetListMutilUD(parsetree, parsetree->rtable, parsetree->resultRelations);
} else {
rewriteTargetListUD(parsetree, rt_entry, rt_entry_relation, result_relation);
}
} else if (event == CMD_MERGE) {
* Rewrite each action targetlist separately
*/
foreach (lc1, parsetree->mergeActionList) {
MergeAction* action = (MergeAction*)lfirst(lc1);
switch (action->commandType) {
case CMD_DELETE:
break;
case CMD_UPDATE:
action->targetList = rewriteTargetListMergeInto(action->targetList,
action->commandType,
rt_entry_relation,
result_relation,
NULL);
break;
case CMD_INSERT: {
action->targetList = rewriteTargetListMergeInto(action->targetList,
action->commandType,
rt_entry_relation,
result_relation,
NULL);
} break;
default: {
ereport(ERROR,
(errcode(ERRCODE_UNEXPECTED_NODE_STATE),
errmsg("unrecognized commandType: %d", action->commandType)));
} break;
}
}
if (parsetree->upsertQuery != NULL) {
List* querytree_list = QueryRewrite(parsetree->upsertQuery);
if (list_length(querytree_list) != 1) {
ereport(ERROR, (errcode(ERRCODE_INVALID_STATUS ), errmsg("Unexpected status in upsert to merge.")));
}
parsetree->upsertQuery = (Query*)linitial(querytree_list);
}
setExtraUpdatedCols(rt_entry, rt_entry_relation->rd_att);
} else {
ereport(ERROR, (errcode(ERRCODE_INVALID_OPERATION), errmsg("unrecognized commandType: %d", (int)event)));
}
#ifdef PGXC
if (parsetree_list == NIL) {
#endif
* Collect and apply the appropriate rules.
*/
locks = matchLocks(event, rt_entry_relation->rd_rules, result_relation, parsetree);
#ifdef ENABLE_MULTIPLE_NODES
if (IS_PGXC_COORDINATOR) {
product_queries =
fireRules(parsetree, result_relation, event, locks, &instead, &returning, &qual_product);
}
#else
product_queries =
fireRules(parsetree, result_relation, event, locks, &instead, &returning, &qual_product);
#endif
* Relation has rules in multiple-relations modifying doesn't support,
* which is checked in CheckUDRelations.
*/
Assert(list_length(parsetree->resultRelations) <= 1 || product_queries == NULL);
* If we have a VALUES RTE with any remaining untouched DEFAULT items,
* and we got any product queries, finalize the VALUES RTE for each
* product query (replacing the remaining DEFAULT items with NULLs).
* We don't do this for the original query, because we know that it
* must be an auto-insert on a view, and so should use the base
* relation's defaults for any remaining DEFAULT items.
*/
if (defaults_remaining && product_queries != NIL) {
ListCell* n = NULL;
* Each product query has its own copy of the VALUES RTE at the
* same index in the rangetable, so we must finalize each one.
*/
foreach(n, product_queries) {
Query* pt = (Query*)lfirst(n);
RangeTblEntry* values_rte = rt_fetch(values_rte_index, pt->rtable);
rewriteValuesRTE(pt, values_rte, rt_entry_relation, attrnos, true);
}
}
if (product_queries != NIL) {
rewriteRelations = lappend_oid(rewriteRelations, RelationGetRelid(rt_entry_relation));
}
List* tempResultRelations = (List*)copyObject(parsetree->resultRelations);
foreach (resultRel, tempResultRelations) {
result_relation = lfirst_int(resultRel);
heap_close(rt_entry_relation, NoLock);
rt_entry = rt_fetch(result_relation, parsetree->rtable);
rt_entry_relation = heap_open(rt_entry->relid, NoLock);
* If there was no unqualified INSTEAD rule, and the target relation
* is a view without any INSTEAD OF triggers, see if the view can be
* automatically updated. If so, we perform the necessary query
* transformation here and add the resulting query to the
* product_queries list, so that it gets recursively rewritten if
* necessary.
*
* If the view cannot be automatically updated, we throw an error here
* which is OK since the query would fail at runtime anyway. Throwing
* the error here is preferable to the executor check since we have
* more detailed information available about why the view isn't
* updatable.
*/
if (!instead && rt_entry_relation->rd_rel->relkind == RELKIND_VIEW &&
!view_has_instead_trigger(rt_entry_relation, event)) {
* If there were any qualified INSTEAD rules, don't allow the view
* to be automatically updated (an unqualified INSTEAD rule or
* INSTEAD OF trigger is required).
*
* The messages here should match execMain.c's CheckValidResultRel
* and in principle make those checks in executor unnecessary, but
* we keep them just in case.
*/
if (qual_product != NULL) {
switch (parsetree->commandType) {
case CMD_INSERT:
ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot insert into view \"%s\"",
RelationGetRelationName(rt_entry_relation)),
errdetail("Views with conditional DO INSTEAD rules are not "
"automatically updatable."),
errhint("To enable inserting into the view, provide an INSTEAD OF INSERT trigger "
"or an unconditional ON INSERT DO INSTEAD rule.")));
break;
case CMD_UPDATE:
ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot update view \"%s\"",
RelationGetRelationName(rt_entry_relation)),
errdetail("Views with conditional DO INSTEAD rules are not "
"automatically updatable."),
errhint("To enable updating the view, provide an INSTEAD OF UPDATE trigger "
"or an unconditional ON UPDATE DO INSTEAD rule.")));
break;
case CMD_DELETE:
ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot delete from view \"%s\"",
RelationGetRelationName(rt_entry_relation)),
errdetail("Views with conditional DO INSTEAD rules are not "
"automatically updatable."),
errhint("To enable deleting from the view, provide an INSTEAD OF DELETE trigger "
"or an unconditional ON DELETE DO INSTEAD rule.")));
break;
default:
ereport(ERROR, (errmsg("unrecognized CmdType: %d", (int)parsetree->commandType)));
break;
}
}
* Attempt to rewrite the query to automatically update the view.
* This throws an error if the view can't be automatically
* updated.
*/
parsetree = rewriteTargetView(parsetree, rt_entry_relation, result_relation);
* Set the "instead" flag, as if there had been an unqualified
* INSTEAD, to prevent the original query from being included a
* second time below. The transformation will have rewritten any
* RETURNING list, so we can also set "returning" to forestall
* throwing an error below.
*/
instead = true;
returning = true;
rewriteView = true;
* If there were any unqualified INSTEAD rules, rewriteRelations
* may contain duplicated oid. But it is ok cause we just use the
* list to check if recursive.
*/
rewriteRelations = lappend_oid(rewriteRelations, RelationGetRelid(rt_entry_relation));
}
}
pfree(tempResultRelations);
* At this point product_queries contains any DO ALSO rule actions.
* Add the rewritten query before or after those. This must match
* the handling the original query would have gotten below, if
* we allowed it to be included again.
*/
if (rewriteView) {
if (parsetree->commandType == CMD_INSERT)
product_queries = lcons(parsetree, product_queries);
else
product_queries = lappend(product_queries, parsetree);
}
* If we got any product queries, recursively rewrite them --- but
* first check for recursion!
*/
if (product_queries != NIL) {
ListCell* n = NULL;
rewrite_event* rev = NULL;
int i;
foreach (n, rewrite_events) {
rev = (rewrite_event*)lfirst(n);
if (list_member_oid(rewriteRelations, rev->relation) && rev->event == event)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("infinite recursion detected in rules for relation \"%s\"",
RelationGetRelationName(RelationIdGetRelation(rev->relation)))));
}
foreach (n, rewriteRelations) {
rev = (rewrite_event*)palloc(sizeof(rewrite_event));
rev->relation = lfirst_oid(n);
rev->event = event;
rewrite_events = lcons(rev, rewrite_events);
}
foreach (n, product_queries) {
Query* pt = (Query*)lfirst(n);
List* newstuff = NULL;
newstuff = RewriteQuery(pt, rewrite_events);
rewritten = list_concat(rewritten, newstuff);
}
for (i = 0; i < list_length(rewriteRelations); i++) {
rewrite_events = list_delete_first(rewrite_events);
}
}
* If there is an INSTEAD, and the original query has a RETURNING, we
* have to have found a RETURNING in the rule(s), else fail. (Because
* DefineQueryRewrite only allows RETURNING in unconditional INSTEAD
* rules, there's no need to worry whether the substituted RETURNING
* will actually be executed --- it must be.)
*
* Ignore for multiple modifying cause returning clause is not supported.
*/
if ((instead || qual_product != NULL) && parsetree->returningList && !returning) {
ereport_for_each_cmdtype(event, rt_entry_relation);
}
heap_close(rt_entry_relation, NoLock);
#ifdef PGXC
} else {
foreach (pt_cell, parsetree_list) {
Query* query = NULL;
query = (Query*)lfirst(pt_cell);
* Collect and apply the appropriate rules.
*/
locks = matchLocks(event, rt_entry_relation->rd_rules, result_relation, query);
if (locks != NIL) {
List* product_queries = NIL;
if (IS_PGXC_COORDINATOR)
product_queries =
fireRules(query, result_relation, event, locks, &instead, &returning, &qual_product);
qual_product_list = lappend(qual_product_list, qual_product);
* If we got any product queries, recursively rewrite them --- but
* first check for recursion!
*/
if (product_queries != NIL) {
ListCell* n = NULL;
rewrite_event* rev = NULL;
foreach (n, rewrite_events) {
rev = (rewrite_event*)lfirst(n);
if (rev->relation == RelationGetRelid(rt_entry_relation) && rev->event == event)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("infinite recursion detected in rules for relation \"%s\"",
RelationGetRelationName(rt_entry_relation))));
}
rev = (rewrite_event*)palloc(sizeof(rewrite_event));
rev->relation = RelationGetRelid(rt_entry_relation);
rev->event = event;
rewrite_events = lcons(rev, rewrite_events);
foreach (n, product_queries) {
Query* pt = (Query*)lfirst(n);
List* newstuff = NIL;
newstuff = RewriteQuery(pt, rewrite_events);
rewritten = list_concat(rewritten, newstuff);
}
rewrite_events = list_delete_first(rewrite_events);
}
}
* If there is an INSTEAD, and the original query has a RETURNING, we
* have to have found a RETURNING in the rule(s), else fail. (Because
* DefineQueryRewrite only allows RETURNING in unconditional INSTEAD
* rules, there's no need to worry whether the substituted RETURNING
* will actually be executed --- it must be.)
*/
if ((instead || qual_product != NULL) && query->returningList && !returning) {
ereport_for_each_cmdtype(event, rt_entry_relation);
}
}
heap_close(rt_entry_relation, NoLock);
}
}
if (parsetree_list == NIL) {
#endif
* For INSERTs, the original query is done first; for UPDATE/DELETE, it is
* done last. This is needed because update and delete rule actions might
* not do anything if they are invoked after the update or delete is
* performed. The command counter increment between the query executions
* makes the deleted (and maybe the updated) tuples disappear so the scans
* for them in the rule actions cannot find them.
*
* If we found any unqualified INSTEAD, the original query is not done at
* all, in any form. Otherwise, we add the modified form if qualified
* INSTEADs were found, else the unmodified form.
*/
if (!instead) {
if (parsetree->commandType == CMD_INSERT) {
if (qual_product != NULL)
rewritten = lcons(qual_product, rewritten);
else
rewritten = lcons(parsetree, rewritten);
} else {
if (qual_product != NULL)
rewritten = lappend(rewritten, qual_product);
else
rewritten = lappend(rewritten, parsetree);
}
}
#ifdef PGXC
} else {
int query_no = 0;
foreach (pt_cell, parsetree_list) {
Query* query = NULL;
Query* qual = NULL;
query = (Query*)lfirst(pt_cell);
if (instead == false) {
if (qual_product_list != NIL)
qual = (Query*)list_nth(qual_product_list, query_no);
if (query->commandType == CMD_INSERT) {
if (qual != NULL)
rewritten = lcons(qual, rewritten);
else
rewritten = lcons(query, rewritten);
} else {
if (qual != NULL)
rewritten = lappend(rewritten, qual);
else
rewritten = lappend(rewritten, query);
}
}
query_no++;
}
}
#endif
* If the original query has a CTE list, and we generated more than one
* non-utility result query, we have to fail because we'll have copied the
* CTE list into each result query. That would break the expectation of
* single evaluation of CTEs. This could possibly be fixed by
* restructuring so that a CTE list can be shared across multiple Query
* and PlannableStatement nodes.
*/
if (parsetree->cteList != NIL) {
int qcount = 0;
foreach (lc1, rewritten) {
Query* q = (Query*)lfirst(lc1);
if (q->commandType != CMD_UTILITY)
qcount++;
}
if (qcount > 1)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("WITH cannot be used in a query that is rewritten by rules into multiple queries")));
}
if (parsetree->isReplace) {
foreach (lc1, rewritten) {
Query* q = (Query*)lfirst(lc1);
q->isReplace = parsetree->isReplace;
}
}
return rewritten;
}
* QueryRewrite -
* Primary entry point to the query rewriter.
* Rewrite one query via query rewrite system, possibly returning 0
* or many queries.
*
* NOTE: the parsetree must either have come straight from the parser,
* or have been scanned by AcquireRewriteLocks to acquire suitable locks.
*/
List* QueryRewrite(Query* parsetree)
{
uint64 input_query_id = parsetree->queryId;
List* querylist = NIL;
List* results = NIL;
ListCell* l = NULL;
CmdType origCmdType;
bool foundOriginalQuery = false;
Query* lastInstead = NULL;
* This function is only applied to top-level original queries
*/
AssertEreport(parsetree->querySource == QSRC_ORIGINAL, MOD_OPT, "");
AssertEreport(parsetree->canSetTag, MOD_OPT, "");
* Step 1
*
* Apply all non-SELECT rules possibly getting 0 or many queries
*/
querylist = RewriteQuery(parsetree, NIL);
* Step 2
*
* Apply all the RIR rules on each query
*
* This is also a handy place to mark each query with the original queryId
*/
results = NIL;
foreach (l, querylist) {
Query* query = (Query*)lfirst(l);
query = fireRIRrules(query, NIL, false);
query->queryId = input_query_id;
results = lappend(results, query);
}
* Step 3
*
* Determine which, if any, of the resulting queries is supposed to set
* the command-result tag; and update the canSetTag fields accordingly.
*
* If the original query is still in the list, it sets the command tag.
* Otherwise, the last INSTEAD query of the same kind as the original is
* allowed to set the tag. (Note these rules can leave us with no query
* setting the tag. The tcop code has to cope with this by setting up a
* default tag based on the original un-rewritten query.)
*
* The Asserts verify that at most one query in the result list is marked
* canSetTag. If we aren't checking asserts, we can fall out of the loop
* as soon as we find the original query.
*/
origCmdType = parsetree->commandType;
foundOriginalQuery = false;
lastInstead = NULL;
foreach (l, results) {
Query* query = (Query*)lfirst(l);
if (query->querySource == QSRC_ORIGINAL) {
AssertEreport(query->canSetTag, MOD_OPT, "");
#ifndef PGXC
AssertEreport(!foundOriginalQuery, MOD_OPT, "");
#endif
foundOriginalQuery = true;
#ifndef USE_ASSERT_CHECKING
break;
#endif
} else {
AssertEreport(!query->canSetTag, MOD_OPT, "");
if (query->commandType == origCmdType &&
(query->querySource == QSRC_INSTEAD_RULE || query->querySource == QSRC_QUAL_INSTEAD_RULE))
lastInstead = query;
}
}
if (!foundOriginalQuery && lastInstead != NULL)
lastInstead->canSetTag = true;
if (CONVERT_STRING_DIGIT_TO_NUMERIC) {
foreach (l, results) {
(void)PreprocessOperator((Node*)lfirst(l), NULL);
}
}
return results;
}
Const* processResToConst(char* value, Oid atttypid, Oid collid)
{
Const *con = NULL;
uint len = strlen(value);
char *str_value = (char *)palloc(len + 1);
errno_t rc = strncpy_s(str_value, len + 1, value, len + 1);
securec_check(rc, "\0", "\0");
str_value[len] = '\0';
Datum str_datum = CStringGetDatum(str_value);
if (atttypid == BOOLOID) {
if (strcmp(str_value, "t") == 0) {
con = makeConst(BOOLOID, -1, InvalidOid, sizeof(bool), BoolGetDatum(true), false, true);
} else {
con = makeConst(BOOLOID, -1, InvalidOid, sizeof(bool), BoolGetDatum(false), false, true);
}
} else {
con = makeConst(UNKNOWNOID, -1, collid, -2, str_datum, false, false);
}
return con;
}
#ifdef PGXC
char* GetCreateViewStmt(Query* parsetree, CreateTableAsStmt* stmt)
{
AssertEreport(IsA(stmt->query, Query), MOD_OPT, "");
ViewStmt* view_stmt = makeNode(ViewStmt);
view_stmt->view = stmt->into->rel;
view_stmt->query = stmt->query;
view_stmt->view->relpersistence = RELPERSISTENCE_PERMANENT;
view_stmt->aliases = stmt->into->colNames;
view_stmt->options = stmt->into->options;
view_stmt->relkind = OBJECT_MATVIEW;
view_stmt->ivm = stmt->into->ivm;
#ifdef ENABLE_MULTIPLE_NODES
PGXCSubCluster* subcluster = NULL;
if (stmt->into->subcluster == NULL && view_stmt->ivm) {
char *group_name = ng_get_group_group_name(stmt->groupid);
subcluster = makeNode(PGXCSubCluster);
subcluster->clustertype = SUBCLUSTER_GROUP;
subcluster->members = list_make1(makeString(group_name));
view_stmt->subcluster = subcluster;
stmt->into->subcluster = subcluster;
} else {
view_stmt->subcluster = stmt->into->subcluster;
}
#endif
parsetree->commandType = CMD_UTILITY;
parsetree->utilityStmt = (Node*)view_stmt;
StringInfo cquery = makeStringInfo();
deparse_query(parsetree, cquery, NIL, false, false);
return cquery->data;
}
static bool findAttrByName(const char* attributeName, List* tableElts, int maxlen)
{
ListCell* lc = NULL;
int i = 0;
foreach (lc, tableElts) {
if (i >= maxlen) {
return false;
}
Node* node = (Node*)lfirst(lc);
if (IsA(node, ColumnDef)) {
ColumnDef* def = (ColumnDef*)node;
if (pg_strcasecmp(attributeName, def->colname) == 0)
return true;
}
++i;
}
return false;
}
* for create table as in B foramt, add type's oid and typemod in tableElts
*/
static void addInitAttrType(List* tableElts)
{
ListCell* lc = NULL;
foreach (lc, tableElts) {
Node* node = (Node*)lfirst(lc);
if (IsA(node, ColumnDef)) {
ColumnDef* def = (ColumnDef*)node;
typenameTypeIdAndMod(NULL, def->typname, &def->typname->typeOid, &def->typname->typemod);
}
}
}
char* GetCreateTableStmt(Query* parsetree, CreateTableAsStmt* stmt)
{
CreateStmt* create_stmt = makeNode(CreateStmt);
create_stmt->relation = stmt->into->rel;
create_stmt->charset = PG_INVALID_ENCODING;
IntoClause* into = stmt->into;
List* tableElts = NIL;
if (u_sess->attr.attr_sql.sql_compatibility == B_FORMAT) {
tableElts = stmt->into->tableElts;
addInitAttrType(tableElts);
}
int initlen = list_length(tableElts);
AssertEreport(IsA(stmt->query, Query), MOD_OPT, "");
Query* cparsetree = (Query*)stmt->query;
List* tlist = cparsetree->targetList;
* Based on the targetList, populate the column information for the target
* table. If a column name list was specified in CREATE TABLE AS, override
* the column names derived from the query. (Too few column names are OK, too
* many are not.).
*/
ListCell* col = NULL;
ListCell* lc = list_head(into->colNames);
foreach (col, tlist) {
TargetEntry* tle = (TargetEntry*)lfirst(col);
ColumnDef* coldef = NULL;
ClientLogicColumnRef *coldef_enc = NULL;
TypeName* tpname = NULL;
if (IsA(tle->expr, Var)) {
Var* ColTypProperty = (Var*)(tle->expr);
* It's possible that the column is of a collatable type but the
* collation could not be resolved, so double-check. (We must check
* this here because DefineRelation would adopt the type's default
* collation rather than complaining.)
*/
if (!OidIsValid(ColTypProperty->varcollid) && type_is_collatable(ColTypProperty->vartype))
ereport(ERROR,
(errcode(ERRCODE_INDETERMINATE_COLLATION),
errmsg("no collation was derived for column \"%s\" with collatable type %s",
tle->resname,
format_type_be(ColTypProperty->vartype)),
errhint("Use the COLLATE clause to set the collation explicitly.")));
}
if (tle->resjunk)
continue;
if (u_sess->attr.attr_sql.sql_compatibility == B_FORMAT && findAttrByName(tle->resname, tableElts, initlen)) {
continue;
}
coldef = makeNode(ColumnDef);
tpname = makeNode(TypeName);
if (lc != NULL) {
coldef->colname = strVal(lfirst(lc));
lc = lnext(lc);
} else
coldef->colname = pstrdup(tle->resname);
coldef->inhcount = 0;
coldef->is_local = true;
coldef->is_not_null = false;
* but the cost is heavy, so make it the default method without forbiting compressing.
* refer to ExecCreateTableAs() --> CreateIntoRelDestReceiver() --> intorel_startup()
*/
coldef->cmprs_mode = ATT_CMPR_UNDEFINED;
coldef->raw_default = NULL;
coldef->cooked_default = NULL;
coldef->update_default = NULL;
coldef->constraints = NIL;
coldef->collOid = exprCollation((Node*)tle->expr);
* Set typeOid and typemod. The name of the type is derived while
* generating query
*/
tpname->typeOid = exprType((Node*)tle->expr);
tpname->typemod = exprTypmod((Node*)tle->expr);
tpname->charset = exprCharset((Node*)tle->expr);
* If the column of source relation is encrypted
* instead of copying its typeOid directly
* we should get its original defination from the catalog
*/
if (is_enc_type(tpname->typeOid)) {
coldef_enc = get_column_enc_def(tle->resorigtbl, tle->resname);
if (coldef_enc != NULL) {
coldef_enc->dest_typname = makeTypeNameFromOid(tpname->typeOid, -1);
tpname->typeOid = coldef_enc->orig_typname->typeOid;
tpname->typemod = coldef_enc->orig_typname->typemod;
}
coldef->clientLogicColumnRef = coldef_enc;
}
coldef->typname = tpname;
tableElts = lappend(tableElts, coldef);
}
if (lc != NULL)
ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR),
errmsg("%s specifies too many column names",
stmt->relkind == OBJECT_MATVIEW ? "CREATE MATERIALIZED VIEW" : "CREATE TABLE AS")));
* Set column information and the distribution mechanism (which will be
* NULL for SELECT INTO and the default mechanism will be picked)
*/
create_stmt->tableElts = tableElts;
create_stmt->distributeby = stmt->into->distributeby;
create_stmt->subcluster = stmt->into->subcluster;
create_stmt->tablespacename = stmt->into->tableSpaceName;
create_stmt->oncommit = stmt->into->onCommit;
create_stmt->row_compress = stmt->into->row_compress;
create_stmt->options = stmt->into->options;
create_stmt->ivm = stmt->into->ivm;
create_stmt->relkind = stmt->relkind == OBJECT_MATVIEW ? RELKIND_MATVIEW : RELKIND_RELATION;
if (u_sess->attr.attr_sql.sql_compatibility == B_FORMAT) {
create_stmt->autoIncStart = stmt->into->autoIncStart;
}
* Check consistency of arguments
*/
if (create_stmt->oncommit != ONCOMMIT_NOOP &&
create_stmt->relation->relpersistence != RELPERSISTENCE_TEMP &&
create_stmt->relation->relpersistence != RELPERSISTENCE_GLOBAL_TEMP) {
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION), errmsg("ON COMMIT can only be used on temporary tables")));
}
#ifdef ENABLE_MULTIPLE_NODES
if (create_stmt->subcluster == NULL && create_stmt->relkind == RELKIND_MATVIEW && create_stmt->ivm) {
PGXCSubCluster* subcluster = NULL;
char *group_name = ng_get_group_group_name(stmt->groupid);
subcluster = makeNode(PGXCSubCluster);
subcluster->clustertype = SUBCLUSTER_GROUP;
subcluster->members = list_make1(makeString(group_name));
create_stmt->subcluster = subcluster;
stmt->into->subcluster = subcluster;
}
#endif
* Now build a utility statement in order to run the CREATE TABLE DDL on
* the local and remote nodes. We keep others fields as it is since they
* are ignored anyways by deparse_query.
*/
parsetree->commandType = CMD_UTILITY;
parsetree->utilityStmt = (Node*)create_stmt;
StringInfo cquery = makeStringInfo();
deparse_query(parsetree, cquery, NIL, false, false);
return cquery->data;
}
static bool selectNeedRecovery(Query* query)
{
if (!query->hasRecursive || query->sql_statement == NULL) {
return false;
}
return strcasestr(query->sql_statement, "CONNECT") != NULL;
}
* @Description: copy(shallow) hints which needs to be displayed in top.
* (e.g. pull "select HINT..." to "Insert HINT INTO XXX SELECT HINT..." )
* @in src: hint state.
* @out dest: hint state.
*/
static void _copy_top_HintState(HintState *dest, HintState *src)
{
if (dest == NULL || src == NULL) {
return;
}
dest->stream_hint = src->stream_hint;
dest->gather_hint = src->gather_hint;
dest->cache_plan_hint = src->cache_plan_hint;
dest->set_hint = src->set_hint;
dest->no_gpc_hint = src->no_gpc_hint;
dest->multi_node_hint = src->multi_node_hint;
dest->skew_hint = src->skew_hint;
dest->predpush_hint = src->predpush_hint;
dest->predpush_same_level_hint = src->predpush_same_level_hint;
dest->rewrite_hint = src->rewrite_hint;
dest->no_expand_hint = src->no_expand_hint;
}
char* GetInsertIntoStmt(CreateTableAsStmt* stmt, bool hasNewColumn)
{
* If target table name is the same as an existed one and schema name is NULL, INSERT INTO
* statement may not find the right target table. Therefore we should get the schema name
* first so that the INSERT INTO statement can insert into the target table.
*/
RangeVar *relation = stmt->into->rel;
if (relation->schemaname == NULL && relation->relpersistence != RELPERSISTENCE_TEMP) {
Oid namespaceid = RangeVarGetAndCheckCreationNamespace(relation, NoLock, NULL, RELKIND_RELATION);
relation->schemaname = get_namespace_name(namespaceid);
}
StringInfo cquery = makeStringInfo();
deparse_query((Query*)stmt->query, cquery, NIL, false, false, stmt->parserSetupArg);
char* selectstr = pstrdup(cquery->data);
* Check if we should recover from the rewriting performed on the select part,
* e.g. for START WITH cases we need to do this after rewriting
*/
Query* select_query = (Query*)stmt->query;
if (selectNeedRecovery(select_query)) {
selectstr = pstrdup(select_query->sql_statement);
}
initStringInfo(cquery);
appendStringInfo(cquery, "INSERT ");
HintState *top_hintState = HintStateCreate();
_copy_top_HintState(top_hintState, ((Query *)stmt->query)->hintState);
get_hint_string(top_hintState, cquery);
if (top_hintState)
pfree((void *)top_hintState);
if (relation->schemaname)
appendStringInfo(
cquery, " INTO %s.%s", quote_identifier(relation->schemaname), quote_identifier(relation->relname));
else
appendStringInfo(cquery, " INTO %s", quote_identifier(relation->relname));
if (u_sess->attr.attr_sql.sql_compatibility == B_FORMAT && hasNewColumn && !stmt->into->skipData) {
appendStringInfoString(cquery, " (");
ListCell* lc = NULL;
const char* delimiter = "";
foreach (lc, select_query->targetList) {
TargetEntry* tle = (TargetEntry*)lfirst(lc);
if (tle->resjunk)
continue;
appendStringInfoString(cquery, delimiter);
delimiter = ", ";
appendStringInfo(cquery, "%s", quote_identifier(tle->resname));
}
appendStringInfoString(cquery, ")");
}
* If the original sql contains "WITH NO DATA", just create
* the table without inserting any data.
*/
if (stmt->into->skipData)
appendStringInfoString(cquery, " select null where false");
else
appendStringInfo(cquery, " %s", selectstr);
if (u_sess->attr.attr_sql.sql_compatibility == B_FORMAT && hasNewColumn && !stmt->into->skipData) {
switch (stmt->into->onduplicate) {
case DUPLICATE_ERROR:
break;
case DUPLICATE_IGNORE:
appendStringInfoString(cquery, " ON DUPLICATE KEY UPDATE NOTHING");
break;
case DUPLICATE_REPLACE: {
appendStringInfoString(cquery, " ON DUPLICATE KEY UPDATE ");
ListCell* lc = NULL;
const char* delimiter = "";
foreach (lc, select_query->targetList) {
TargetEntry* tle = (TargetEntry*)lfirst(lc);
if (tle->resjunk)
continue;
appendStringInfoString(cquery, delimiter);
delimiter = ", ";
appendStringInfo(cquery, "%s = VALUES(%s)", quote_identifier(tle->resname), quote_identifier(tle->resname));
}
break;
}
default:
break;
}
}
return cquery->data;
}
List *query_rewrite_multiset_stmt(Query *query)
{
List* querytree_list = NIL;
VariableMultiSetStmt* muti_stmt = (VariableMultiSetStmt*)query->utilityStmt;
List* stmts = muti_stmt->args;
ListCell* cell = NULL;
VariableSetStmt *set_stmt;
foreach(cell, stmts) {
Node* stmt = (Node*)lfirst(cell);
if (nodeTag(stmt) == T_AlterSystemStmt) {
AlterSystemStmt* alter_sys_stmt = (AlterSystemStmt *)stmt;
set_stmt = alter_sys_stmt->setstmt;
} else {
set_stmt = (VariableSetStmt*)stmt;
}
if (list_length(set_stmt->args) > 1) {
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("set %s takes only one argument", set_stmt->name)));
}
if(set_stmt->kind == VAR_SET_VALUE) {
List *resultlist = NIL;
ListCell *l = NULL;
foreach(l, set_stmt->args) {
Node* expr = (Node*)lfirst(l);
Node* node = NULL;
if(IsA(expr, A_Const)) {
node = expr;
} else {
node = eval_const_expression_value(NULL, expr, NULL);
if(nodeTag(node) != T_Const) {
node = QueryRewriteNonConstant(expr);
}
node = transferConstToAconst(node);
}
resultlist = lappend(resultlist, (A_Const*)node);
}
list_free(set_stmt->args);
set_stmt->args = resultlist;
}
}
querytree_list = list_make1(query);
return querytree_list;
}
List *query_rewrite_set_stmt(Query *query)
{
List* querytree_list = NIL;
VariableSetStmt *stmt = (VariableSetStmt *)query->utilityStmt;
if(DB_IS_CMPT(B_FORMAT) && stmt->kind == VAR_SET_VALUE &&
(u_sess->attr.attr_common.enable_set_variable_b_format || ENABLE_SET_VARIABLES)) {
List *resultlist = NIL;
ListCell *l = NULL;
foreach(l, stmt->args) {
Node* expr = (Node*)lfirst(l);
Node* node = NULL;
if(nodeTag(expr) == T_A_Const) {
node = expr;
} else {
node = eval_const_expression_value(NULL, expr, NULL);
if(nodeTag(node) != T_Const) {
node = QueryRewriteNonConstant(expr);
}
node = transferConstToAconst(node);
}
resultlist = lappend(resultlist, (A_Const*)node);
}
list_free(stmt->args);
stmt->args = resultlist;
}
querytree_list = list_make1(query);
return querytree_list;
}
List *QueryRewriteRefresh(Query *parse_tree)
{
RefreshMatViewStmt* stmt = NULL;
RewriteRule *rule = NULL;
Oid matviewOid;
Relation matviewRel;
List *actions = NIL;
Query *dataQuery;
List* raw_parsetree_list = NIL;
if (parse_tree->commandType != CMD_UTILITY || !IsA(parse_tree->utilityStmt, RefreshMatViewStmt)) {
ereport(ERROR,
(errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
errmsg("Unexpected commandType or intoClause is not set properly")));
}
stmt = (RefreshMatViewStmt *)parse_tree->utilityStmt;
RangeVar *relation = stmt->relation;
if (relation->schemaname == NULL && relation->relpersistence != RELPERSISTENCE_TEMP) {
Oid namespaceid = RangeVarGetAndCheckCreationNamespace(relation, NoLock, NULL, RELKIND_MATVIEW);
relation->schemaname = get_namespace_name(namespaceid);
}
StringInfo tquery = makeStringInfo();
initStringInfo(tquery);
if (IS_PGXC_COORDINATOR) {
appendStringInfo(tquery, "REFRESH MATERIALIZED VIEW ");
} else {
appendStringInfo(tquery, "TRUNCATE TABLE ");
}
if (relation->schemaname)
appendStringInfo(
tquery, "%s.%s", quote_identifier(relation->schemaname), quote_identifier(relation->relname));
else
appendStringInfo(tquery, "%s", quote_identifier(relation->relname));
char *refresh_sql = tquery->data;
if (IS_PGXC_COORDINATOR) {
ExecUtilityStmtOnNodes(refresh_sql, NULL, false, false, EXEC_ON_DATANODES, false);
} else {
raw_parsetree_list = pg_parse_query(refresh_sql);
return pg_analyze_and_rewrite((Node*)linitial(raw_parsetree_list), refresh_sql, NULL, 0);
}
StringInfo cquery = makeStringInfo();
* Get a lock until end of transaction.
*/
matviewOid = RangeVarGetRelidExtended(stmt->relation,
AccessExclusiveLock, false, false, false, false,
RangeVarCallbackOwnsMatView, NULL);
matviewRel = heap_open(matviewOid, NoLock);
if (matviewRel->rd_rel->relkind != RELKIND_MATVIEW) {
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("\"%s\" is not a materialized view",
RelationGetRelationName(matviewRel))));
}
if (IS_PGXC_COORDINATOR) {
CheckRefreshMatview(matviewRel, false);
}
rule = matviewRel->rd_rules->rules[0];
actions = rule->actions;
if (list_length(actions) != 1) {
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("the rule for materialized view \"%s\" is not a single action",
RelationGetRelationName(matviewRel))));
}
dataQuery = (Query *) linitial(actions);
Query* parsetree = (Query*)copyObject(dataQuery);
deparse_query(parsetree, cquery, NIL, false, false, NULL);
char* selectstr = pstrdup(cquery->data);
pfree_ext(parsetree);
initStringInfo(cquery);
appendStringInfo(cquery, "INSERT ");
HintState *hintState = dataQuery->hintState;
if (hintState != NULL && hintState->multi_node_hint) {
appendStringInfo(cquery, " /*+ multinode */ ");
}
if (hintState != NULL && hintState->sql_ignore_hint) {
appendStringInfo(cquery, " /*+ ignore_error */ ");
}
if (relation->schemaname) {
appendStringInfo(cquery, " INTO %s.%s", quote_identifier(relation->schemaname),
quote_identifier(relation->relname));
} else {
appendStringInfo(cquery, " INTO %s", quote_identifier(relation->relname));
}
appendStringInfo(cquery, " %s", selectstr);
char *insert_select_sql = cquery->data;
raw_parsetree_list = pg_parse_query(insert_select_sql);
heap_close(matviewRel, NoLock);
Assert(IsA(linitial(raw_parsetree_list), InsertStmt));
linitial_node(InsertStmt, raw_parsetree_list)->isRewritten = true;
return pg_analyze_and_rewrite((Node*)linitial(raw_parsetree_list), insert_select_sql, NULL, 0);
}
* Rewrite the CREATE TABLE AS and SELECT INTO queries as a
* INSERT INTO .. SELECT query. The target table must be created first using
* utility command processing. This takes care of creating the target table on
* all the Coordinators and the Datanodes.
*/
List* QueryRewriteCTAS(Query* parsetree)
{
List* raw_parsetree_list = NIL;
CreateTableAsStmt* stmt = NULL;
Query* zparsetree = NULL;
char* view_sql = NULL;
if (parsetree->commandType != CMD_UTILITY || !IsA(parsetree->utilityStmt, CreateTableAsStmt)) {
ereport(ERROR,
(errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
errmsg("Unexpected commandType or intoClause is not set properly")));
}
stmt = (CreateTableAsStmt*)parsetree->utilityStmt;
Query* cparsetree = (Query*)copyObject(parsetree);
bool hasNewColumn = stmt->into->tableElts != NULL;
char* create_sql = GetCreateTableStmt(cparsetree, stmt);
stmt->into->tableElts = NULL;
if (stmt->relkind == OBJECT_MATVIEW) {
zparsetree = (Query*)copyObject(cparsetree);
view_sql = GetCreateViewStmt(zparsetree, stmt);
ViewStmt *mvStmt = (ViewStmt *)zparsetree->utilityStmt;
mvStmt->mv_stmt = cparsetree->utilityStmt;
mvStmt->mv_sql = create_sql;
}
if (stmt->relkind != OBJECT_MATVIEW) {
processutility_context proutility_cxt;
proutility_cxt.parse_tree = cparsetree->utilityStmt;
proutility_cxt.query_string = create_sql;
proutility_cxt.readOnlyTree = false;
proutility_cxt.params = NULL;
proutility_cxt.is_top_level = true;
ProcessUtility(&proutility_cxt, NULL, false, NULL, PROCESS_UTILITY_GENERATED, true);
}
if (stmt->relkind == OBJECT_MATVIEW) {
Query *query = (Query *)stmt->query;
processutility_context proutility_cxt;
proutility_cxt.parse_tree = zparsetree->utilityStmt;
proutility_cxt.query_string = view_sql;
proutility_cxt.readOnlyTree = false;
proutility_cxt.params = NULL;
proutility_cxt.is_top_level = true;
ProcessUtility(&proutility_cxt, NULL, false, NULL, PROCESS_UTILITY_GENERATED, true);
create_matview_meta(query, stmt->into->rel, stmt->into->ivm);
if (stmt->into->ivm) {
return NIL;
}
if (IS_PGXC_COORDINATOR && IsConnFromCoord()) {
return NIL;
}
}
* Now fold the CTAS statement into an INSERT INTO statement. The
* utility is no more required.
*/
parsetree->utilityStmt = NULL;
* Now fold the CTAS statement into an INSERT INTO statement. The
* utility is no more required.
*/
parsetree->utilityStmt = NULL;
char* insert_into_sqlstr = GetInsertIntoStmt(stmt, hasNewColumn);
raw_parsetree_list = pg_parse_query(insert_into_sqlstr);
Assert(IsA(linitial(raw_parsetree_list), InsertStmt));
linitial_node(InsertStmt, raw_parsetree_list)->isRewritten = true;
if (stmt->parserSetup != NULL)
return pg_analyze_and_rewrite_params(
(Node*)linitial(raw_parsetree_list), insert_into_sqlstr, (ParserSetupHook)stmt->parserSetup, stmt->parserSetupArg);
else {
if (strchr(insert_into_sqlstr, '$') == NULL) {
return pg_analyze_and_rewrite((Node*)linitial(raw_parsetree_list), insert_into_sqlstr, NULL, 0);
} else {
return pg_analyze_and_rewrite((Node*)linitial(raw_parsetree_list),
insert_into_sqlstr,
parsetree->fixed_paramTypes,
parsetree->fixed_numParams);
}
}
}
* Get value from a subquery or non-constant expression by constructing SQL.
* input:
node: a subquery expression or non-constant expression.
* return: Const expression.
*/
Node* QueryRewriteNonConstant(Node *node)
{
Query* cparsetree = NULL;
Const* con = NULL;
List *p_target = NIL;
Node *res = NULL;
SelectStmt* select_stmt = makeNode(SelectStmt);
TargetEntry* target = makeTargetEntry((Expr*)node, (AttrNumber)1, NULL, false);
p_target = list_make1(target);
select_stmt->targetList = list_copy(p_target);
cparsetree = (Query *)makeNode(Query);
cparsetree->commandType = CMD_SELECT;
cparsetree->utilityStmt = (Node *)select_stmt;
cparsetree->hasSubLinks = true;
cparsetree->canSetTag = true;
cparsetree->jointree = makeFromExpr(NULL, NULL);
cparsetree->targetList = list_copy(p_target);
StringInfo select_sql = makeStringInfo();
deparse_query(cparsetree, select_sql, NIL, false, false);
StmtResult *result = NULL;
if (u_sess->attr.attr_sql.dolphin) {
int origin = u_sess->attr.attr_common.bytea_output;
u_sess->attr.attr_common.bytea_output = BYTEA_OUTPUT_HEX;
PG_TRY();
{
result = execute_stmt(select_sql->data, true);
}
PG_CATCH();
{
u_sess->attr.attr_common.bytea_output = origin;
PG_RE_THROW();
}
PG_END_TRY();
u_sess->attr.attr_common.bytea_output = origin;
} else {
result = execute_stmt(select_sql->data, true);
}
DestroyStringInfo(select_sql);
bool isnull = result->isnulls[0];
if (isnull) {
Oid collid = exprCollation(node);
con = makeConst(UNKNOWNOID, -1, collid, -2, (Datum)0, true, false);
(*result->pub.rDestroy)((DestReceiver *)result);
return (Node *)con;
}
char* value = (char *)linitial((List *)linitial(result->tuples));
Oid atttypid = result->atttypids[0];
con = processResToConst(value, atttypid, result->collids[0]);
res = atttypid == BOOLOID ? (Node *)con : type_transfer((Node *)con, atttypid, true);
(*result->pub.rDestroy)((DestReceiver *)result);
return res;
}
List* QueryRewriteSelectIntoVarList(Node *node, int res_len)
{
Query *parsetree = (Query *)((SubLink *)node)->subselect;
List *resList = NIL;
StringInfo select_sql = makeStringInfo();
deparse_query(parsetree, select_sql, NIL, false, false);
StmtResult *result = execute_stmt(select_sql->data, true);
DestroyStringInfo(select_sql);
if (result->tuples == NULL) {
ListCell *target_cell = list_head(parsetree->targetList);
for (int i = 0; i < res_len; i++, target_cell = lnext(target_cell)) {
Oid collid = exprCollation((Node*)((TargetEntry*)lfirst(target_cell))->expr);
Const *con = makeConst(UNKNOWNOID, -1, collid, -2, (Datum)0, true, false);
resList = lappend(resList, con);
}
(*result->pub.rDestroy)((DestReceiver *)result);
return resList;
}
if(result->tuples->length > 1) {
ereport(ERROR,
(errcode(ERRCODE_INVALID_OPERATION),
errmsg("select result consisted of more than one row")));
}
ListCell *stmt_res_cur = list_head((List *)linitial(result->tuples));
for (int idx = 0; idx < res_len; idx++) {
Oid collid = result->collids[idx];
if (result->isnulls[idx]) {
Const *con = makeConst(UNKNOWNOID, -1, collid, -2, (Datum)0, true, false);
resList = lappend(resList, con);
} else {
char *value = (char *)lfirst(stmt_res_cur);
Oid atttypid = result->atttypids[idx];
Const *con = processResToConst(value, atttypid, collid);
Node* rnode = atttypid == BOOLOID ? (Node*)con : type_transfer((Node *)con, atttypid, true);
resList = lappend(resList, rnode);
stmt_res_cur = lnext(stmt_res_cur);
}
}
(*result->pub.rDestroy)((DestReceiver *)result);
return resList;
}
#endif
