*
* rewriteDefine.cpp
* routines for defining a rewrite rule
*
* 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/rewriteDefine.cpp
*
* -------------------------------------------------------------------------
*/
#include "postgres.h"
#include "knl/knl_variable.h"
#include "access/heapam.h"
#include "access/multixact.h"
#include "access/tableam.h"
#include "access/transam.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/dependency.h"
#include "catalog/heap.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "catalog/objectaccess.h"
#include "catalog/pg_class.h"
#include "catalog/pg_rewrite.h"
#include "catalog/pg_namespace.h"
#include "catalog/pgxc_class.h"
#include "catalog/pgxc_slice.h"
#include "catalog/storage.h"
#include "commands/sec_rls_cmds.h"
#include "commands/vacuum.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
#include "nodes/plannodes.h"
#include "parser/parse_utilcmd.h"
#include "pgxc/pgxc.h"
#include "rewrite/rewriteDefine.h"
#include "rewrite/rewriteManip.h"
#include "rewrite/rewriteSupport.h"
#include "tcop/utility.h"
#ifdef ENABLE_MULTIPLE_NODES
#include "tsdb/utils/ts_redis.h"
#endif
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/rel.h"
#include "utils/rel_gs.h"
#include "utils/sec_rls_utils.h"
#include "utils/syscache.h"
#include "utils/snapmgr.h"
#include "catalog/pg_object.h"
static void checkRuleResultList(List* targetList, TupleDesc resultDesc, bool isSelect);
static bool checkWhetherForbiddenRule(Oid relId);
static bool setRuleCheckAsUser_walker(Node* node, Oid* context);
static void setRuleCheckAsUser_Query(Query* qry, Oid userid);
* InsertRule -
* takes the arguments and inserts them as a row into the system
* relation "pg_rewrite"
*/
static Oid InsertRule(char* rulname, int evtype, Oid eventrel_oid, AttrNumber evslot_index, bool evinstead,
Node* event_qual, List* action, bool replace)
{
char* evqual = nodeToString(event_qual);
char* actiontree = nodeToString((Node*)action);
Datum values[Natts_pg_rewrite];
bool nulls[Natts_pg_rewrite];
bool replaces[Natts_pg_rewrite];
NameData rname;
Relation pg_rewrite_desc;
HeapTuple tup, oldtup;
Oid rewriteObjectId;
ObjectAddress myself, referenced;
bool is_update = false;
errno_t rc;
* Set up *nulls and *values arrays
*/
rc = memset_s(nulls, sizeof(nulls), false, sizeof(nulls));
securec_check(rc, "", "");
(void)namestrcpy(&rname, rulname);
values[Anum_pg_rewrite_rulename - 1] = NameGetDatum(&rname);
values[Anum_pg_rewrite_ev_class - 1] = ObjectIdGetDatum(eventrel_oid);
values[Anum_pg_rewrite_ev_attr - 1] = Int16GetDatum(evslot_index);
values[Anum_pg_rewrite_ev_type - 1] = CharGetDatum(evtype + '0');
values[Anum_pg_rewrite_ev_enabled - 1] = CharGetDatum(RULE_FIRES_ON_ORIGIN);
values[Anum_pg_rewrite_is_instead - 1] = BoolGetDatum(evinstead);
values[Anum_pg_rewrite_ev_qual - 1] = CStringGetTextDatum(evqual);
values[Anum_pg_rewrite_ev_action - 1] = CStringGetTextDatum(actiontree);
* Ready to store new pg_rewrite tuple
*/
pg_rewrite_desc = heap_open(RewriteRelationId, RowExclusiveLock);
* Check to see if we are replacing an existing tuple
*/
oldtup = SearchSysCache2(RULERELNAME, ObjectIdGetDatum(eventrel_oid), PointerGetDatum(rulname));
if (HeapTupleIsValid(oldtup)) {
if (!replace)
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
errmsg("rule \"%s\" for relation \"%s\" already exists", rulname, get_rel_name(eventrel_oid))));
* When replacing, we don't need to replace every attribute
*/
rc = memset_s(replaces, sizeof(replaces), false, sizeof(replaces));
securec_check(rc, "", "");
replaces[Anum_pg_rewrite_ev_attr - 1] = true;
replaces[Anum_pg_rewrite_ev_type - 1] = true;
replaces[Anum_pg_rewrite_is_instead - 1] = true;
replaces[Anum_pg_rewrite_ev_qual - 1] = true;
replaces[Anum_pg_rewrite_ev_action - 1] = true;
tup = (HeapTuple) tableam_tops_modify_tuple(oldtup, RelationGetDescr(pg_rewrite_desc), values, nulls, replaces);
simple_heap_update(pg_rewrite_desc, &tup->t_self, tup);
ReleaseSysCache(oldtup);
rewriteObjectId = HeapTupleGetOid(tup);
is_update = true;
} else {
tup = heap_form_tuple(pg_rewrite_desc->rd_att, values, nulls);
rewriteObjectId = simple_heap_insert(pg_rewrite_desc, tup);
}
CatalogUpdateIndexes(pg_rewrite_desc, tup);
tableam_tops_free_tuple(tup);
if (is_update)
(void)deleteDependencyRecordsFor(RewriteRelationId, rewriteObjectId, false);
* Install dependency on rule's relation to ensure it will go away on
* relation deletion. If the rule is ON SELECT, make the dependency
* implicit --- this prevents deleting a view's SELECT rule. Other kinds
* of rules can be AUTO.
*/
myself.classId = RewriteRelationId;
myself.objectId = rewriteObjectId;
myself.objectSubId = 0;
referenced.classId = RelationRelationId;
referenced.objectId = eventrel_oid;
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, (evtype == CMD_SELECT) ? DEPENDENCY_INTERNAL : DEPENDENCY_AUTO);
* Also install dependencies on objects referenced in action and qual.
*/
recordDependencyOnExpr(&myself, (Node*)action, NIL, DEPENDENCY_NORMAL);
if (event_qual != NULL) {
Query* qry = (Query*)linitial(action);
qry = getInsertSelectQuery(qry, NULL);
recordDependencyOnExpr(&myself, event_qual, qry->rtable, DEPENDENCY_NORMAL);
}
InvokeObjectAccessHook(OAT_POST_CREATE, RewriteRelationId, rewriteObjectId, 0, NULL);
heap_close(pg_rewrite_desc, RowExclusiveLock);
return rewriteObjectId;
}
* DefineRule
* Execute a CREATE RULE command.
*/
ObjectAddress DefineRule(RuleStmt* stmt, const char* queryString)
{
List* actions = NIL;
Node* whereClause = NULL;
Oid relId;
transformRuleStmt(stmt, queryString, &actions, &whereClause);
* Find and lock the relation. Lock level should match
* DefineQueryRewrite.
*/
relId = RangeVarGetRelid(stmt->relation, AccessExclusiveLock, false);
if (checkWhetherForbiddenRule(relId)) {
ereport(ERROR,
(errmodule(MOD_EXECUTOR),
errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("not supported to create a rule on this table.")));
}
return DefineQueryRewrite(stmt->rulename, relId, whereClause, stmt->event, stmt->instead, stmt->replace, actions);
}
* DefineQueryRewrite
* Create a rule
*
* This is essentially the same as DefineRule() except that the rule's
* action and qual have already been passed through parse analysis.
*/
ObjectAddress DefineQueryRewrite(
char* rulename, Oid event_relid, Node* event_qual, CmdType event_type, bool is_instead, bool replace, List* action)
{
Relation event_relation;
int event_attno;
ListCell* l = NULL;
Query* query = NULL;
bool RelisBecomingView = false;
Datum values[Natts_pg_class];
bool nulls[Natts_pg_class];
bool replaces[Natts_pg_class];
errno_t rc;
Oid ruleId = InvalidOid;
ObjectAddress address;
* If we are installing an ON SELECT rule, we had better grab
* AccessExclusiveLock to ensure no SELECTs are currently running on the
* event relation. For other types of rules, it would be sufficient to
* grab ShareRowExclusiveLock to lock out insert/update/delete actions and
* to ensure that we lock out current CREATE RULE statements; but because
* of race conditions in access to catalog entries, we can't do that yet.
*
* Note that this lock level should match the one used in DefineRule.
*/
event_relation = heap_open(event_relid, AccessExclusiveLock);
* Verify relation is of a type that rules can sensibly be applied to.
*/
if (event_relation->rd_rel->relkind != RELKIND_RELATION &&
event_relation->rd_rel->relkind != RELKIND_VIEW &&
event_relation->rd_rel->relkind != RELKIND_MATVIEW &&
event_relation->rd_rel->relkind != RELKIND_CONTQUERY)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table or view", RelationGetRelationName(event_relation))));
if (!g_instance.attr.attr_common.allowSystemTableMods && !u_sess->attr.attr_common.IsInplaceUpgrade &&
IsSystemRelation(event_relation))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system catalog", RelationGetRelationName(event_relation))));
* Check user has permission to apply rules to this relation.
*/
if (!pg_class_ownercheck(event_relid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, RelationGetRelationName(event_relation));
* No rule actions that modify OLD or NEW
*/
foreach (l, action) {
query = (Query*)lfirst(l);
if (linitial2_int(query->resultRelations) == 0)
continue;
if (query != getInsertSelectQuery(query, NULL))
continue;
if (linitial2_int(query->resultRelations) == PRS2_OLD_VARNO)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("rule actions on OLD are not implemented"),
errhint("Use views or triggers instead.")));
if (linitial2_int(query->resultRelations) == PRS2_NEW_VARNO)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("rule actions on NEW are not implemented"),
errhint("Use triggers instead.")));
}
if (event_type == CMD_UTILITY) {
bool is_copy = false;
if (list_length(action) == 1) {
query = (Query*)linitial(action);
#ifdef ENABLE_MULTIPLE_NODES
is_copy = is_copy_rule(query);
#endif
if (is_copy && !is_instead) {
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("Copy rule only support CREATE RULE rulename COPY to relname DO INSTEAD...")));
}
}
}
if (event_type == CMD_SELECT) {
* Rules ON SELECT are restricted to view definitions
*
* So there cannot be INSTEAD NOTHING, ...
*/
if (list_length(action) == 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("INSTEAD NOTHING rules on SELECT are not implemented"),
errhint("Use views instead.")));
* ... there cannot be multiple actions, ...
*/
if (list_length(action) > 1)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("multiple actions for rules on SELECT are not implemented")));
* ... the one action must be a SELECT, ...
*/
query = (Query*)linitial(action);
if (!is_instead || query->commandType != CMD_SELECT || query->utilityStmt != NULL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("rules on SELECT must have action INSTEAD SELECT")));
* ... it cannot contain data-modifying WITH ...
*/
if (query->hasModifyingCTE)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("rules on SELECT must not contain data-modifying statements in WITH")));
* ... there can be no rule qual, ...
*/
if (event_qual != NULL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("event qualifications are not implemented for rules on SELECT")));
* ... the targetlist of the SELECT action must exactly match the
* event relation, ...
*/
checkRuleResultList(query->targetList,
RelationGetDescr(event_relation),
event_relation->rd_rel->relkind != RELKIND_MATVIEW);
* ... there must not be another ON SELECT rule already ...
*/
if (!replace && event_relation->rd_rules != NULL) {
int i;
for (i = 0; i < event_relation->rd_rules->numLocks; i++) {
RewriteRule* rule = NULL;
rule = event_relation->rd_rules->rules[i];
if (rule->event == CMD_SELECT)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("\"%s\" is already a view", RelationGetRelationName(event_relation))));
}
}
* ... and finally the rule must be named _RETURN.
*/
if (strcmp(rulename, ViewSelectRuleName) != 0) {
* In versions before 7.3, the expected name was _RETviewname. For
* backwards compatibility with old pg_dump output, accept that
* and silently change it to _RETURN. Since this is just a quick
* backwards-compatibility hack, limit the number of characters
* checked to a few less than NAMEDATALEN; this saves having to
* worry about where a multibyte character might have gotten
* truncated.
*/
if (strncmp(rulename, "_RET", 4) != 0 ||
strncmp(rulename + 4, RelationGetRelationName(event_relation), NAMEDATALEN - 4 - 4) != 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("view rule for \"%s\" must be named \"%s\"",
RelationGetRelationName(event_relation),
ViewSelectRuleName)));
rulename = pstrdup(ViewSelectRuleName);
}
* Are we converting a relation to a view?
*
* If so, check that the relation is empty because the storage for the
* relation is going to be deleted. Also insist that the rel not have
* any triggers, indexes, or child tables. (Note: these tests are too
* strict, because they will reject relations that once had such but
* don't anymore. But we don't really care, because this whole
* business of converting relations to views is just a kluge to allow
* loading ancient pg_dump files.)
*/
if (event_relation->rd_rel->relkind != RELKIND_VIEW && event_relation->rd_rel->relkind != RELKIND_MATVIEW
&& event_relation->rd_rel->relkind != RELKIND_CONTQUERY) {
TableScanDesc scanDesc;
if (RELATION_IS_PARTITIONED(event_relation)) {
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("could not convert table \"%s\" to a view because it is a partitioned table",
RelationGetRelationName(event_relation)),
errdetail("can not convert partitioned table to view")));
}
scanDesc = tableam_scan_begin(event_relation, SnapshotNow, 0, NULL);
if (tableam_scan_getnexttuple(scanDesc, ForwardScanDirection) != NULL)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("could not convert table \"%s\" to a view because it is not empty",
RelationGetRelationName(event_relation))));
tableam_scan_end(scanDesc);
if (event_relation->rd_rel->relhastriggers)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("could not convert table \"%s\" to a view because it has triggers",
RelationGetRelationName(event_relation)),
errhint("In particular, the table cannot be involved in any foreign key relationships.")));
if (event_relation->rd_rel->relhasindex)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("could not convert table \"%s\" to a view because it has indexes",
RelationGetRelationName(event_relation))));
if (event_relation->rd_rel->relhassubclass)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("could not convert table \"%s\" to a view because it has child tables",
RelationGetRelationName(event_relation))));
if (RelationEnableRowSecurity(event_relation))
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("could not convert table \"%s\" to a view because it has row level security enabled",
RelationGetRelationName(event_relation))));
if (RelationHasRlspolicy(RelationGetRelid(event_relation)))
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("could not convert table \"%s\" to a view because it has row level security policies",
RelationGetRelationName(event_relation))));
RelisBecomingView = true;
}
} else {
* For non-SELECT rules, a RETURNING list can appear in at most one of
* the actions ... and there can't be any RETURNING list at all in a
* conditional or non-INSTEAD rule. (Actually, there can be at most
* one RETURNING list across all rules on the same event, but it seems
* best to enforce that at rule expansion time.) If there is a
* RETURNING list, it must match the event relation.
*/
bool haveReturning = false;
foreach (l, action) {
query = (Query*)lfirst(l);
if (!query->returningList)
continue;
if (haveReturning)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot have multiple RETURNING lists in a rule")));
haveReturning = true;
if (event_qual != NULL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("RETURNING lists are not supported in conditional rules")));
if (!is_instead)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("RETURNING lists are not supported in non-INSTEAD rules")));
checkRuleResultList(query->returningList, RelationGetDescr(event_relation), false);
}
}
* This rule is allowed - prepare to install it.
*/
event_attno = -1;
char originRelKind = event_relation->rd_rel->relkind;
if (action != NIL || is_instead) {
ruleId = InsertRule(rulename, event_type, event_relid, event_attno, is_instead, event_qual, action, replace);
* Set pg_class 'relhasrules' field TRUE for event relation. If
* appropriate, also modify the 'relkind' field to show that the
* relation is now a view.
*
* Important side effect: an SI notice is broadcast to force all
* backends (including me!) to update relcache entries with the new
* rule.
*/
SetRelationRuleStatus(event_relid, true, RelisBecomingView);
}
* If the relation is becoming a view:
* - delete the associated storage files
* - get rid of any system attributes in pg_attribute; a view shouldn't
* have any of those
* - remove the toast table; there is no need for it anymore, and its
* presence would make vacuum slightly more complicated
* - set relkind to RELKIND_VIEW, and adjust other pg_class fields
* to be appropriate for a view
*
* NB: we had better have AccessExclusiveLock to do this ...
* ---------------------------------------------------------------------
*/
if (RelisBecomingView) {
Relation relationRelation;
Oid toastrelid;
HeapTuple classTup;
HeapTuple nctup;
Form_pg_class classForm;
Oid nspid;
relationRelation = heap_open(RelationRelationId, RowExclusiveLock);
toastrelid = event_relation->rd_rel->reltoastrelid;
RelationDropStorage(event_relation);
DeleteSystemAttributeTuples(event_relid);
* Drop the toast table if any. (This won't take care of updating the
* toast fields in the relation's own pg_class entry; we handle that
* below.)
*/
if (OidIsValid(toastrelid)) {
ObjectAddress toastobject;
* Delete the dependency of the toast relation on the main
* relation so we can drop the former without dropping the latter.
*/
(void)deleteDependencyRecordsFor(RelationRelationId, toastrelid, false);
CommandCounterIncrement();
toastobject.classId = RelationRelationId;
toastobject.objectId = toastrelid;
toastobject.objectSubId = 0;
performDeletion(&toastobject, DROP_RESTRICT, PERFORM_DELETION_INTERNAL);
}
* SetRelationRuleStatus may have updated the pg_class row, so we must
* advance the command counter before trying to update it again.
*/
CommandCounterIncrement();
* Fix pg_class entry to look like a normal view's, including setting
* the correct relkind and removal of reltoastrelid/reltoastidxid of
* the toast table we potentially removed above.
*/
classTup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(event_relid));
if (!HeapTupleIsValid(classTup))
ereport(ERROR,
(errmodule(MOD_OPT_REWRITE),
errcode(ERRCODE_CACHE_LOOKUP_FAILED),
errmsg("cache lookup failed for relation %u", event_relid)));
classForm = (Form_pg_class)GETSTRUCT(classTup);
char newObjectType = RELKIND_VIEW;
nspid = classForm->relnamespace;
classForm->reltablespace = InvalidOid;
classForm->relpages = 0;
classForm->reltuples = 0;
classForm->relallvisible = 0;
classForm->reltoastrelid = InvalidOid;
classForm->reltoastidxid = InvalidOid;
classForm->relhasindex = false;
classForm->relkind = newObjectType;
classForm->relhasoids = false;
classForm->relhaspkey = false;
classForm->relfrozenxid = (ShortTransactionId)InvalidTransactionId;
rc = memset_s(values, sizeof(values), 0, sizeof(values));
securec_check(rc, "\0", "\0");
rc = memset_s(nulls, sizeof(nulls), false, sizeof(nulls));
securec_check(rc, "\0", "\0");
rc = memset_s(replaces, sizeof(replaces), false, sizeof(replaces));
securec_check(rc, "\0", "\0");
replaces[Anum_pg_class_relfrozenxid64 - 1] = true;
values[Anum_pg_class_relfrozenxid64 - 1] = TransactionIdGetDatum(InvalidTransactionId);
replaces[Anum_pg_class_reloptions - 1] = true;
nulls[Anum_pg_class_reloptions - 1] = true;
nctup = (HeapTuple) tableam_tops_modify_tuple(classTup, RelationGetDescr(relationRelation), values, nulls, replaces);
simple_heap_update(relationRelation, &nctup->t_self, nctup);
CatalogUpdateIndexes(relationRelation, nctup);
tableam_tops_free_tuple(nctup);
tableam_tops_free_tuple(classTup);
updatePgObjectType(event_relid, originRelKind, newObjectType);
heap_close(relationRelation, RowExclusiveLock);
#ifdef ENABLE_MULTIPLE_NODES
RemovePgxcClass(event_relid);
RemovePgxcSlice(event_relid);
deleteDependencyRecordsFor(PgxcClassRelationId, event_relid, false);
if (IS_PGXC_COORDINATOR && !IsConnFromCoord()) {
StringInfoData dropbuf;
char* nspname = get_namespace_name(nspid);
char* relname = get_rel_name(event_relid);
const char* quoteNsp = quote_identifier(nspname);
const char* quoteRel = quote_identifier(relname);
initStringInfo(&dropbuf);
appendStringInfo(&dropbuf, "DROP TABLE %s.%s;", quoteNsp, quoteRel);
ExecUtilityStmtOnNodes(dropbuf.data, NULL, false, false, EXEC_ON_DATANODES, false);
}
#endif
}
ObjectAddressSet(address, RewriteRelationId, ruleId);
heap_close(event_relation, NoLock);
return address;
}
static bool checkWhetherForbiddenRule(Oid relId)
{
Relation rel = heap_open(relId, NoLock);
Oid namespaceId = RelationGetNamespace(rel);
bool forbidden = false;
if (namespaceId == PG_DB4AI_NAMESPACE && !strcmp(RelationGetRelationName(rel), "snapshot")) {
forbidden = true;
}
heap_close(rel, NoLock);
return forbidden;
}
* checkRuleResultList
* Verify that targetList produces output compatible with a tupledesc
*
* The targetList might be either a SELECT targetlist, or a RETURNING list;
* isSelect tells which. (This is mostly used for choosing error messages,
* but also we don't enforce column name matching for RETURNING.)
*/
static void checkRuleResultList(List* targetList, TupleDesc resultDesc, bool isSelect)
{
ListCell* tllist = NULL;
int i;
i = 0;
foreach (tllist, targetList) {
TargetEntry* tle = (TargetEntry*)lfirst(tllist);
int32 tletypmod;
Form_pg_attribute attr;
char* attname = NULL;
if (tle->resjunk)
continue;
i++;
if (i > resultDesc->natts)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
isSelect ? errmsg("SELECT rule's target list has too many entries")
: errmsg("RETURNING list has too many entries")));
attr = &resultDesc->attrs[i - 1];
attname = NameStr(attr->attname);
* Disallow dropped columns in the relation. This won't happen in the
* cases we actually care about (namely creating a view via CREATE
* TABLE then CREATE RULE, or adding a RETURNING rule to a view).
* Trying to cope with it is much more trouble than it's worth,
* because we'd have to modify the rule to insert dummy NULLs at the
* right positions.
*/
if (attr->attisdropped)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot convert relation containing dropped columns to view")));
if (isSelect && strcmp(tle->resname, attname) != 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("SELECT rule's target entry %d has different column name from \"%s\"", i, attname)));
if (attr->atttypid != exprType((Node*)tle->expr) && !(attr->attcollation || exprCollation((Node*)tle->expr)))
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
isSelect ? errmsg("SELECT rule's target entry %d has different type from column \"%s\"", i, attname)
: errmsg("RETURNING list's entry %d has different type from column \"%s\"", i, attname)));
* Allow typmods to be different only if one of them is -1, ie,
* "unspecified". This is necessary for cases like "numeric", where
* the table will have a filled-in default length but the select
* rule's expression will probably have typmod = -1.
*/
tletypmod = exprTypmod((Node*)tle->expr);
if (attr->atttypmod != tletypmod && attr->atttypmod != -1 && tletypmod != -1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
isSelect ? errmsg("SELECT rule's target entry %d has different size from column \"%s\"", i, attname)
: errmsg("RETURNING list's entry %d has different size from column \"%s\"", i, attname)));
}
if (i != resultDesc->natts)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
isSelect ? errmsg("SELECT rule's target list has too few entries")
: errmsg("RETURNING list has too few entries")));
}
* setRuleCheckAsUser
* Recursively scan a query or expression tree and set the checkAsUser
* field to the given userid in all rtable entries.
*
* Note: for a view (ON SELECT rule), the checkAsUser field of the OLD
* RTE entry will be overridden when the view rule is expanded, and the
* checkAsUser field of the NEW entry is irrelevant because that entry's
* requiredPerms bits will always be zero. However, for other types of rules
* it's important to set these fields to match the rule owner. So we just set
* them always.
*/
void setRuleCheckAsUser(Node* node, Oid userid)
{
(void)setRuleCheckAsUser_walker(node, &userid);
}
static bool setRuleCheckAsUser_walker(Node* node, Oid* context)
{
if (node == NULL)
return false;
if (IsA(node, Query)) {
setRuleCheckAsUser_Query((Query*)node, *context);
return false;
}
return expression_tree_walker(node, (bool (*)())setRuleCheckAsUser_walker, (void*)context);
}
static void setRuleCheckAsUser_Query(Query* qry, Oid userid)
{
ListCell* l = NULL;
foreach (l, qry->rtable) {
RangeTblEntry* rte = (RangeTblEntry*)lfirst(l);
if (rte->rtekind == RTE_SUBQUERY) {
setRuleCheckAsUser_Query(rte->subquery, userid);
} else
rte->checkAsUser = userid;
}
foreach (l, qry->cteList) {
CommonTableExpr* cte = (CommonTableExpr*)lfirst(l);
setRuleCheckAsUser_Query((Query*)cte->ctequery, userid);
}
if (qry->hasSubLinks)
(void)query_tree_walker(qry, (bool (*)())setRuleCheckAsUser_walker, (void*)&userid, QTW_IGNORE_RC_SUBQUERIES);
}
* Change the firing semantics of an existing rule.
*/
void EnableDisableRule(Relation rel, const char* rulename, char fires_when)
{
Relation pg_rewrite_desc;
Oid owningRel = RelationGetRelid(rel);
Oid eventRelationOid;
HeapTuple ruletup;
bool changed = false;
* Find the rule tuple to change.
*/
pg_rewrite_desc = heap_open(RewriteRelationId, RowExclusiveLock);
ruletup = SearchSysCacheCopy2(RULERELNAME, ObjectIdGetDatum(owningRel), PointerGetDatum(rulename));
if (!HeapTupleIsValid(ruletup))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("rule \"%s\" for relation \"%s\" does not exist", rulename, get_rel_name(owningRel))));
* Verify that the user has appropriate permissions.
*/
eventRelationOid = ((Form_pg_rewrite)GETSTRUCT(ruletup))->ev_class;
AssertEreport(eventRelationOid == owningRel, MOD_OPT, "");
if (!pg_class_ownercheck(eventRelationOid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS, get_rel_name(eventRelationOid));
* Change ev_enabled if it is different from the desired new state.
*/
if (DatumGetChar((int32)(((Form_pg_rewrite)GETSTRUCT(ruletup))->ev_enabled)) != fires_when) {
((Form_pg_rewrite)GETSTRUCT(ruletup))->ev_enabled = CharGetDatum(fires_when);
simple_heap_update(pg_rewrite_desc, &ruletup->t_self, ruletup);
CatalogUpdateIndexes(pg_rewrite_desc, ruletup);
changed = true;
}
tableam_tops_free_tuple(ruletup);
heap_close(pg_rewrite_desc, RowExclusiveLock);
* If we changed anything, broadcast a SI inval message to force each
* backend (including our own!) to rebuild relation's relcache entry.
* Otherwise they will fail to apply the change promptly.
*/
if (changed)
CacheInvalidateRelcache(rel);
}
* Rename an existing rewrite rule.
*
* This is unused code at the moment. Note that it lacks a permissions check.
*/
#ifdef NOT_USED
void RenameRewriteRule(Oid owningRel, const char* oldName, const char* newName)
{
Relation pg_rewrite_desc;
HeapTuple ruletup;
pg_rewrite_desc = heap_open(RewriteRelationId, RowExclusiveLock);
ruletup = SearchSysCacheCopy2(RULERELNAME, ObjectIdGetDatum(owningRel), PointerGetDatum(oldName));
if (!HeapTupleIsValid(ruletup))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("rule \"%s\" for relation \"%s\" does not exist", oldName, get_rel_name(owningRel))));
if (IsDefinedRewriteRule(owningRel, newName))
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
errmsg("rule \"%s\" for relation \"%s\" already exists", newName, get_rel_name(owningRel))));
(void)namestrcpy(&(((Form_pg_rewrite)GETSTRUCT(ruletup))->rulename), newName);
simple_heap_update(pg_rewrite_desc, &ruletup->t_self, ruletup);
CatalogUpdateIndexes(pg_rewrite_desc, ruletup);
tableam_tops_free_tuple(ruletup);
heap_close(pg_rewrite_desc, RowExclusiveLock);
}
#endif