*
* indxpath.cpp
* Routines to determine which indexes are usable for scanning a
* given relation, and create Paths accordingly.
*
* 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/path/indxpath.cpp
*
* -------------------------------------------------------------------------
*/
#include "postgres.h"
#include "knl/knl_variable.h"
#include <math.h>
#include "access/skey.h"
#include "access/sysattr.h"
#include "access/multi_redo_api.h"
#include "catalog/index.h"
#include "catalog/pg_am.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_opfamily.h"
#include "catalog/pg_type.h"
#include "catalog/pg_proc.h"
#include "nodes/makefuncs.h"
#include "optimizer/clauses.h"
#include "optimizer/cost.h"
#include "optimizer/pathnode.h"
#include "optimizer/paths.h"
#include "optimizer/planner.h"
#include "optimizer/predtest.h"
#include "optimizer/restrictinfo.h"
#include "optimizer/var.h"
#include "parser/parse_hint.h"
#include "parser/parsetree.h"
#include "utils/builtins.h"
#include "utils/bytea.h"
#include "utils/lsyscache.h"
#include "utils/pg_locale.h"
#include "utils/selfuncs.h"
#include "optimizer/gplanmgr.h"
#include "instruments/instr_statement.h"
#include "utils/expr_distinct.h"
#include "catalog/gs_collation.h"
#define IsBooleanOpfamily(opfamily) ((opfamily) == BOOL_BTREE_FAM_OID || \
(opfamily) == BOOL_HASH_FAM_OID || (opfamily) == BOOL_UBTREE_FAM_OID)
#define BTREE_AM_OID 403
#define IndexCollMatchesExprColl(idxcollation, exprcollation) \
((idxcollation) == InvalidOid || (idxcollation) == (exprcollation))
#define PrefixKeyColumnMatched(indexkey, operand) \
((indexkey) && IsA((indexkey), PrefixKey) && IsA(((PrefixKey*)(indexkey))->arg, Var) && \
(operand) && IsA((operand), Var) && \
((Var*)((PrefixKey*)(indexkey))->arg)->varno == ((Var*)(operand))->varno && \
((Var*)((PrefixKey*)(indexkey))->arg)->varattno == ((Var*)(operand))->varattno)
typedef enum {
SAOP_PER_AM,
SAOP_ALLOW,
SAOP_REQUIRE
} SaOpControl;
typedef enum {
ST_INDEXSCAN,
ST_BITMAPSCAN,
ST_ANYSCAN
} ScanTypeControl;
typedef struct {
bool nonempty;
List* indexclauses[INDEX_MAX_KEYS];
} IndexClauseSet;
typedef struct {
Path* path;
List* quals;
List* preds;
Bitmapset* clauseids;
} PathClauseUsage;
typedef struct {
Cost costsofar;
List* qualsofar;
Bitmapset* clauseidsofar;
ListCell* lastcell;
List* paths;
int startPath;
} ChooseBitmapAndInfo;
typedef struct {
int maxBufLen;
char maxSortBuf[4];
int minBufLen;
char minSortBuf[4];
} PadContent;
static void consider_index_join_clauses(PlannerInfo* root, RelOptInfo* rel, IndexOptInfo* index,
IndexClauseSet* rclauseset, IndexClauseSet* jclauseset, IndexClauseSet* eclauseset, List** bitindexpaths);
static void consider_index_join_outer_rels(PlannerInfo* root, RelOptInfo* rel, IndexOptInfo* index,
IndexClauseSet* rclauseset, IndexClauseSet* jclauseset, IndexClauseSet* eclauseset, List** bitindexpaths,
List* indexjoinclauses, int considered_clauses, List** considered_relids);
static void get_join_index_paths(PlannerInfo* root, RelOptInfo* rel, IndexOptInfo* index, IndexClauseSet* rclauseset,
IndexClauseSet* jclauseset, IndexClauseSet* eclauseset, List** bitindexpaths, Relids relids,
List** considered_relids);
static bool eclass_already_used(EquivalenceClass* parent_ec, Relids oldrelids, List* indexjoinclauses);
static bool bms_equal_any(Relids relids, List* relids_list);
static void get_index_paths(
PlannerInfo* root, RelOptInfo* rel, IndexOptInfo* index, IndexClauseSet* clauses, List** bitindexpaths);
static List* build_index_paths(PlannerInfo* root, RelOptInfo* rel, IndexOptInfo* index, IndexClauseSet* clauses,
bool useful_predicate, SaOpControl saop_control, ScanTypeControl scantype);
static List* build_paths_for_OR(
PlannerInfo* root, RelOptInfo* rel, List* clauses, List* other_clauses, IndexFeature idx_feature);
static List* drop_indexable_join_clauses(RelOptInfo* rel, List* clauses);
static Path* choose_bitmap_and(PlannerInfo* root, RelOptInfo* rel, List* paths, List* globalPartIndexPaths = NIL);
static int path_usage_comparator(const void* a, const void* b);
static Cost bitmap_scan_cost_est(PlannerInfo* root, RelOptInfo* rel, Path* ipath);
static Cost bitmap_and_cost_est(PlannerInfo* root, RelOptInfo* rel, List* paths);
static PathClauseUsage* classify_index_clause_usage(Path* path, List** clauselist);
static Relids get_bitmap_tree_required_outer(Path* bitmapqual);
static Bitmapset* get_bitmap_tree_required_upper(Path* bitmapqual);
static void find_indexpath_quals(Path* bitmapqual, List** quals, List** preds);
static int find_list_position(Node* node, List** nodelist);
static bool check_index_only(PlannerInfo* root, RelOptInfo* rel, IndexOptInfo* index);
static double get_loop_count(PlannerInfo* root, Relids outer_relids);
static void match_restriction_clauses_to_index(RelOptInfo* rel, IndexOptInfo* index, IndexClauseSet* clauseset);
static void match_join_clauses_to_index(
PlannerInfo* root, RelOptInfo* rel, IndexOptInfo* index,
IndexClauseSet* clauseset, List** joinorclauses);
static void match_eclass_clauses_to_index(PlannerInfo* root, IndexOptInfo* index, IndexClauseSet* clauseset);
static void match_clauses_to_index(IndexOptInfo* index, List* clauses, IndexClauseSet* clauseset);
static void match_clause_to_index(IndexOptInfo* index, RestrictInfo* rinfo, IndexClauseSet* clauseset);
static bool match_clause_to_indexcol(IndexOptInfo* index, int indexcol, RestrictInfo* rinfo);
static bool is_indexable_operator(Oid expr_op, Oid opfamily, bool indexkey_on_left);
static bool match_rowcompare_to_indexcol(
IndexOptInfo* index, int indexcol, Oid opfamily, Oid idxcollation, RowCompareExpr* clause);
static void match_pathkeys_to_index(
IndexOptInfo* index, List* pathkeys, List** orderby_clauses_p, List** clause_columns_p);
static Expr* match_clause_to_ordering_op(IndexOptInfo* index, int indexcol, Expr* clause, Oid pk_opfamily);
static bool match_boolean_index_clause(Node* clause, int indexcol, IndexOptInfo* index);
static bool match_special_index_operator(Expr* clause, Oid opfamily, Oid idxcollation,
bool indexkey_on_left, IndexOptInfo* index, int indexcol);
static Expr* expand_boolean_index_clause(Node* clause, int indexcol, IndexOptInfo* index);
static List* expand_indexqual_opclause(IndexOptInfo* index, RestrictInfo* rinfo, Oid opfamily, Oid idxcollation,
int indexcol);
static RestrictInfo* expand_indexqual_rowcompare(RestrictInfo* rinfo, IndexOptInfo* index, int indexcol);
static List* prefix_quals(Node* leftop, Oid opfamily, Oid collation, Const* prefix,
Pattern_Prefix_Status pstatus, int prefixkey_len);
static List* prefix_quals_with_encdoing(Node* leftop, Oid opfamily, Oid collation, Const* prefix,
Pattern_Prefix_Status pstatus, int prefixkey_len);
static List* network_prefix_quals(Node* leftop, Oid expr_op, Oid opfamily, Datum rightop);
static Datum string_to_datum(const char* str, Oid datatype);
static Const* string_to_const(const char* str, Oid datatype);
static int get_index_column_prefix_lenth(IndexOptInfo *index, int indexcol);
static Const* prefix_const_node(Const* con, int prefix_len, Oid datatype);
static RestrictInfo* rewrite_opclause_for_prefixkey(
RestrictInfo *rinfo, IndexOptInfo* index, Oid opfamily, int prefix_len);
static Const *pad_string_in_like(PadContent content, const Const *strConst, int length, bool isPadMax);
static int get_pad_length(Node *leftop, int prefixLen);
static PadContent get_pad_content(Oid collation);
static bool scalar_array_can_match_prefixkey(Node *saop_rexpr);
RestrictInfo *expand_indexqual_scalar_array_op_expr(IndexOptInfo *index, RestrictInfo *rinfo,
Oid opfamily, int indexcol);
void check_report_cause_type(FuncExpr *funcExpr, int indkey);
Node* match_first_var_to_indkey(Node* node, int indkey);
* create_index_paths
*
* Generate all interesting index paths for the given relation.
* Candidate paths are added to the rel's pathlist (using add_path).
*
* To be considered for an index scan, an index must match one or more
* restriction clauses or join clauses from the query's qual condition,
* or match the query's ORDER BY condition, or have a predicate that
* matches the query's qual condition.
*
* There are two basic kinds of index scans. A "plain" index scan uses
* only restriction clauses (possibly none at all) in its indexqual,
* so it can be applied in any context. A "parameterized" index scan uses
* join clauses (plus restriction clauses, if available) in its indexqual.
* When joining such a scan to one of the relations supplying the other
* variables used in its indexqual, the parameterized scan must appear as
* the inner relation of a nestloop join; it can't be used on the outer side,
* nor in a merge or hash join. In that context, values for the other rels'
* attributes are available and fixed during any one scan of the indexpath.
*
* An IndexPath is generated and submitted to add_path() for each plain or
* parameterized index scan this routine deems potentially interesting for
* the current query.
*
* 'rel' is the relation for which we want to generate index paths
*
* Note: check_partial_indexes() must have been run previously for this rel.
*
* Note: in cases involving LATERAL references in the relation's tlist, it's
* possible that rel->lateral_relids is nonempty. Currently, we include
* lateral_relids into the parameterization reported for each path, but don't
* take it into account otherwise. The fact that any such rels *must* be
* available as parameter sources perhaps should influence our choices of
* index quals ... but for now, it doesn't seem worth troubling over.
* In particular, comments below about "unparameterized" paths should be read
* as meaning "unparameterized so far as the indexquals are concerned".
*/
void create_index_paths(PlannerInfo* root, RelOptInfo* rel)
{
List* indexpaths = NIL;
List* bitindexpaths = NIL;
List* bitjoinpaths = NIL;
List* joinorclauses = NIL;
IndexClauseSet rclauseset;
IndexClauseSet jclauseset;
IndexClauseSet eclauseset;
ListCell* lc = NULL;
Bitmapset* required_upper = NULL;
RangeTblEntry *rte = NULL;
if (rel->indexlist == NIL)
return;
* Ignore index scan path when time capsule is enabled in base rel for correctess issue
*/
rte = planner_rt_fetch(rel->relid, root);
if (rel->is_ustore && rte->timecapsule != NULL) {
ereport(DEBUG2, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("Unsupported IndexScan timecapsule-enabled base rel, relName:%s relOid:%u",
rte->relname, rte->relid)));
return;
}
bitindexpaths = bitjoinpaths = joinorclauses = NIL;
foreach (lc, rel->indexlist) {
IndexOptInfo* index = (IndexOptInfo*)lfirst(lc);
AssertEreport(index->ncolumns <= INDEX_MAX_KEYS, MOD_OPT, "Index column number is incorrect");
* Ignore partial indexes that do not match the query.
* (generate_bitmap_or_paths() might be able to do something with
* them, but that's of no concern here.)
*/
if (index->indpred != NIL && !index->predOK) {
continue;
}
* Build paths with global indexes only for un-bounded partition tables.
* The partition bounded tables should be handled by partition iterator
* or local indexes.
*/
if (index->isGlobal && rte && list_length(rte->partitionOidList) > 0) {
continue;
}
* Identify the restriction clauses that can match the index.
*/
errno_t errorno = EOK;
errorno = memset_s(&rclauseset, sizeof(IndexClauseSet), 0, sizeof(rclauseset));
securec_check(errorno, "\0", "\0");
match_restriction_clauses_to_index(rel, index, &rclauseset);
* Build index paths from the restriction clauses. These will be
* non-parameterized paths. Plain paths go directly to add_path(),
* bitmap paths are added to bitindexpaths to be handled below.
*/
get_index_paths(root, rel, index, &rclauseset, &bitindexpaths);
if (SUBQUERY_IS_PARAM(root) && rel->subplanrestrictinfo != NULL) {
match_clauses_to_index(index, rel->subplanrestrictinfo, &rclauseset);
get_index_paths(root, rel, index, &rclauseset, &bitindexpaths);
}
* Identify the join clauses that can match the index. For the moment
* we keep them separate from the restriction clauses. Note that this
* step finds only "loose" join clauses that have not been merged into
* EquivalenceClasses. Also, collect join OR clauses for later.
*/
errorno = memset_s(&jclauseset, sizeof(IndexClauseSet), 0, sizeof(jclauseset));
securec_check(errorno, "\0", "\0");
match_join_clauses_to_index(root, rel, index, &jclauseset, &joinorclauses);
* Look for EquivalenceClasses that can generate joinclauses matching
* the index.
*/
errorno = memset_s(&eclauseset, sizeof(IndexClauseSet), 0, sizeof(eclauseset));
securec_check(errorno, "\0", "\0");
match_eclass_clauses_to_index(root, index, &eclauseset);
* If we found any plain or eclass join clauses, build parameterized
* index paths using them.
*/
if ((jclauseset.nonempty || eclauseset.nonempty)
#ifdef ENABLE_MULTIPLE_NODES
&& !WITHIN_SUBQUERY(root, rte)
#endif
)
consider_index_join_clauses(root, rel, index, &rclauseset, &jclauseset, &eclauseset, &bitjoinpaths);
}
* Generate BitmapOrPaths for any suitable OR-clauses present in the
* restriction list. Add these to bitindexpaths.
*/
indexpaths = generate_bitmap_or_paths(root, rel, rel->baserestrictinfo, NIL, false);
bitindexpaths = list_concat(bitindexpaths, indexpaths);
* Likewise, generate BitmapOrPaths for any suitable OR-clauses present in
* the joinclause list. Add these to bitjoinpaths.
*/
indexpaths = generate_bitmap_or_paths(root, rel, joinorclauses, rel->baserestrictinfo, false);
bitjoinpaths = list_concat(bitjoinpaths, indexpaths);
* Generate BitmapOrPaths for any suitable OR-clauses present in the
* restriction list and joinorclauses just use featured index.
* Add these to bitindexpaths.
*/
IndexFeature indexFeature = getIndexFeature(rel->isPartitionedTable, (rel->bucketInfo != NULL));
if (indexFeature != NONFEATURED_INDEX) {
indexpaths = GenerateBitmapOrPathsWithFeaturedIndex(root, rel, rel->baserestrictinfo, NIL, false, indexFeature);
bitindexpaths = list_concat(bitindexpaths, indexpaths);
indexpaths = GenerateBitmapOrPathsWithFeaturedIndex(root, rel, joinorclauses, rel->baserestrictinfo, false,
indexFeature);
bitjoinpaths = list_concat(bitjoinpaths, indexpaths);
}
* If we found anything usable, generate a BitmapHeapPath for the most
* promising combination of restriction bitmap index paths. Note there
* will be only one such path no matter how many indexes exist. This
* should be sufficient since there's basically only one figure of merit
* (total cost) for such a path.
* Dfs table does not support bitmapscan now.
*/
if (bitindexpaths != NIL && rel->orientation != REL_PAX_ORIENTED) {
Path* bitmapqual = NULL;
BitmapHeapPath* bpath = NULL;
bitmapqual = choose_bitmap_and(root, rel, bitindexpaths);
required_upper = get_bitmap_tree_required_upper(bitmapqual);
bpath = create_bitmap_heap_path(root, rel, bitmapqual, rel->lateral_relids, required_upper, 1.0);
add_path(root, rel, (Path*)bpath);
}
* Likewise, if we found anything usable, generate BitmapHeapPaths for the
* most promising combinations of join bitmap index paths. Our strategy
* is to generate one such path for each distinct parameterization seen
* among the available bitmap index paths. This may look pretty
* expensive, but usually there won't be very many distinct
* parameterizations. (This logic is quite similar to that in
* consider_index_join_clauses, but we're working with whole paths not
* individual clauses.)
* Dfs table does not support bitmapscan now.
*/
if (bitjoinpaths != NIL && rel->orientation != REL_PAX_ORIENTED) {
List* path_outer = NIL;
List* all_path_outers = NIL;
ListCell* lc = NULL;
* path_outer holds the parameterization of each path in bitjoinpaths
* (to save recalculating that several times), while all_path_outers
* holds all distinct parameterization sets.
*/
path_outer = all_path_outers = NIL;
foreach (lc, bitjoinpaths) {
Path* path = (Path*)lfirst(lc);
Relids required_outer;
required_outer = get_bitmap_tree_required_outer(path);
path_outer = lappend(path_outer, required_outer);
if (!bms_equal_any(required_outer, all_path_outers))
all_path_outers = lappend(all_path_outers, required_outer);
}
foreach (lc, all_path_outers) {
Relids max_outers = (Relids)lfirst(lc);
List* this_path_set = NIL;
Path* bitmapqual = NULL;
Relids required_outer = NULL;
double loop_count = 0;
BitmapHeapPath* bpath = NULL;
ListCell* lcp = NULL;
ListCell* lco = NULL;
this_path_set = NIL;
forboth(lcp, bitjoinpaths, lco, path_outer)
{
Path* path = (Path*)lfirst(lcp);
Relids p_outers = (Relids)lfirst(lco);
if (bms_is_subset(p_outers, max_outers))
this_path_set = lappend(this_path_set, path);
}
* Add in restriction bitmap paths, since they can be used
* together with any join paths.
*/
this_path_set = list_concat(this_path_set, bitindexpaths);
bitmapqual = choose_bitmap_and(root, rel, this_path_set);
required_outer = get_bitmap_tree_required_outer(bitmapqual);
required_upper = get_bitmap_tree_required_upper(bitmapqual);
loop_count = get_loop_count(root, required_outer);
bpath = create_bitmap_heap_path(root, rel, bitmapqual, required_outer,
required_upper, loop_count);
add_path(root, rel, (Path*)bpath);
}
}
}
* getIndexFeature
* Get index feature base on baserel feature.
*/
IndexFeature getIndexFeature(bool isPartitioned, bool hasBucket) {
return (IndexFeature)((int)isPartitioned | (((int)hasBucket) << 1));
}
* consider_index_join_clauses
* Given sets of join clauses for an index, decide which parameterized
* index paths to build.
*
* Plain indexpaths are sent directly to add_path, while potential
* bitmap indexpaths are added to *bitindexpaths for later processing.
*
* 'rel' is the index's heap relation
* 'index' is the index for which we want to generate paths
* 'rclauseset' is the collection of indexable restriction clauses
* 'jclauseset' is the collection of indexable simple join clauses
* 'eclauseset' is the collection of indexable clauses from EquivalenceClasses
* '*bitindexpaths' is the list to add bitmap paths to
*/
static void consider_index_join_clauses(PlannerInfo* root, RelOptInfo* rel, IndexOptInfo* index,
IndexClauseSet* rclauseset, IndexClauseSet* jclauseset, IndexClauseSet* eclauseset, List** bitindexpaths)
{
int considered_clauses = 0;
List* considered_relids = NIL;
int indexcol;
* The strategy here is to identify every potentially useful set of outer
* rels that can provide indexable join clauses. For each such set,
* select all the join clauses available from those outer rels, add on all
* the indexable restriction clauses, and generate plain and/or bitmap
* index paths for that set of clauses. This is based on the assumption
* that it's always better to apply a clause as an indexqual than as a
* filter (qpqual); which is where an available clause would end up being
* applied if we omit it from the indexquals.
*
* This looks expensive, but in most practical cases there won't be very
* many distinct sets of outer rels to consider. As a safety valve when
* that's not true, we use a heuristic: limit the number of outer rel sets
* considered to a multiple of the number of clauses considered. (We'll
* always consider using each individual join clause, though.)
*
* For simplicity in selecting relevant clauses, we represent each set of
* outer rels as a maximum set of clause_relids --- that is, the indexed
* relation itself is also included in the relids set. considered_relids
* lists all relids sets we've already tried.
*/
for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++) {
considered_clauses += list_length(jclauseset->indexclauses[indexcol]);
consider_index_join_outer_rels(root,
rel,
index,
rclauseset,
jclauseset,
eclauseset,
bitindexpaths,
jclauseset->indexclauses[indexcol],
considered_clauses,
&considered_relids);
considered_clauses += list_length(eclauseset->indexclauses[indexcol]);
consider_index_join_outer_rels(root,
rel,
index,
rclauseset,
jclauseset,
eclauseset,
bitindexpaths,
eclauseset->indexclauses[indexcol],
considered_clauses,
&considered_relids);
}
}
* consider_index_join_outer_rels
* Generate parameterized paths based on clause relids in the clause list.
*
* Workhorse for consider_index_join_clauses; see notes therein for rationale.
*
* 'rel', 'index', 'rclauseset', 'jclauseset', 'eclauseset', and
* 'bitindexpaths' as above
* 'indexjoinclauses' is a list of RestrictInfos for join clauses
* 'considered_clauses' is the total number of clauses considered (so far)
* '*considered_relids' is a list of all relids sets already considered
*/
static void consider_index_join_outer_rels(PlannerInfo* root, RelOptInfo* rel, IndexOptInfo* index,
IndexClauseSet* rclauseset, IndexClauseSet* jclauseset, IndexClauseSet* eclauseset, List** bitindexpaths,
List* indexjoinclauses, int considered_clauses, List** considered_relids)
{
ListCell* lc = NULL;
foreach (lc, indexjoinclauses) {
RestrictInfo* rinfo = (RestrictInfo*)lfirst(lc);
Relids clause_relids = rinfo->clause_relids;
ListCell* lc2 = NULL;
if (bms_equal_any(clause_relids, *considered_relids))
continue;
* Generate the union of this clause's relids set with each
* previously-tried set. This ensures we try this clause along with
* every interesting subset of previous clauses. However, to avoid
* exponential growth of planning time when there are many clauses,
* limit the number of relid sets accepted to 10 * considered_clauses.
*
* Note: get_join_index_paths adds entries to *considered_relids, but
* it prepends them to the list, so that we won't visit new entries
* during the inner foreach loop. No real harm would be done if we
* did, since the subset check would reject them; but it would waste
* some cycles.
*/
foreach (lc2, *considered_relids) {
Relids oldrelids = (Relids)lfirst(lc2);
* If either is a subset of the other, no new set is possible.
* This isn't a complete test for redundancy, but it's easy and
* cheap. get_join_index_paths will check more carefully if we
* already generated the same relids set.
*/
if (bms_subset_compare(clause_relids, oldrelids) != BMS_DIFFERENT)
continue;
* If this clause was derived from an equivalence class, the
* clause list may contain other clauses derived from the same
* eclass. We should not consider that combining this clause with
* one of those clauses generates a usefully different
* parameterization; so skip if any clause derived from the same
* eclass would already have been included when using oldrelids.
*/
if (rinfo->parent_ec && eclass_already_used(rinfo->parent_ec, oldrelids, indexjoinclauses))
continue;
* If the number of relid sets considered exceeds our heuristic
* limit, stop considering combinations of clauses. We'll still
* consider the current clause alone, though (below this loop).
*/
if (list_length(*considered_relids) >= 10 * considered_clauses)
break;
get_join_index_paths(root,
rel,
index,
rclauseset,
jclauseset,
eclauseset,
bitindexpaths,
bms_union(clause_relids, oldrelids),
considered_relids);
}
get_join_index_paths(
root, rel, index, rclauseset, jclauseset, eclauseset, bitindexpaths, clause_relids, considered_relids);
}
}
* get_join_index_paths
* Generate index paths using clauses from the specified outer relations.
* In addition to generating paths, relids is added to *considered_relids
* if not already present.
*
* Workhorse for consider_index_join_clauses; see notes therein for rationale.
*
* 'rel', 'index', 'rclauseset', 'jclauseset', 'eclauseset',
* 'bitindexpaths', 'considered_relids' as above
* 'relids' is the current set of relids to consider (the target rel plus
* one or more outer rels)
*/
static void get_join_index_paths(PlannerInfo* root, RelOptInfo* rel, IndexOptInfo* index, IndexClauseSet* rclauseset,
IndexClauseSet* jclauseset, IndexClauseSet* eclauseset, List** bitindexpaths, Relids relids,
List** considered_relids)
{
IndexClauseSet clauseset;
int indexcol;
if (bms_equal_any(relids, *considered_relids))
return;
errno_t errorno = EOK;
errorno = memset_s(&clauseset, sizeof(IndexClauseSet), 0, sizeof(clauseset));
securec_check(errorno, "\0", "\0");
for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++) {
ListCell* lc = NULL;
foreach (lc, jclauseset->indexclauses[indexcol]) {
RestrictInfo* rinfo = (RestrictInfo*)lfirst(lc);
if (bms_is_subset(rinfo->clause_relids, relids))
clauseset.indexclauses[indexcol] = lappend(clauseset.indexclauses[indexcol], rinfo);
}
* Add applicable eclass join clauses. The clauses generated for each
* column are redundant (cf generate_implied_equalities_for_indexcol),
* so we need at most one. This is the only exception to the general
* rule of using all available index clauses.
*/
foreach (lc, eclauseset->indexclauses[indexcol]) {
RestrictInfo* rinfo = (RestrictInfo*)lfirst(lc);
if (bms_is_subset(rinfo->clause_relids, relids)) {
clauseset.indexclauses[indexcol] = lappend(clauseset.indexclauses[indexcol], rinfo);
break;
}
}
clauseset.indexclauses[indexcol] =
list_concat(clauseset.indexclauses[indexcol], rclauseset->indexclauses[indexcol]);
if (clauseset.indexclauses[indexcol] != NIL)
clauseset.nonempty = true;
}
Assert(clauseset.nonempty);
get_index_paths(root, rel, index, &clauseset, bitindexpaths);
* Remember we considered paths for this set of relids. We use lcons not
* lappend to avoid confusing the loop in consider_index_join_outer_rels.
*/
*considered_relids = lcons(relids, *considered_relids);
}
* eclass_already_used
* True if any join clause usable with oldrelids was generated from
* the specified equivalence class.
*/
static bool eclass_already_used(EquivalenceClass* parent_ec, Relids oldrelids, List* indexjoinclauses)
{
ListCell* lc = NULL;
foreach (lc, indexjoinclauses) {
RestrictInfo* rinfo = (RestrictInfo*)lfirst(lc);
if (rinfo->parent_ec == parent_ec && bms_is_subset(rinfo->clause_relids, oldrelids))
return true;
}
return false;
}
* bms_equal_any
* True if relids is bms_equal to any member of relids_list
*
* Perhaps this should be in bitmapset.c someday.
*/
static bool bms_equal_any(Relids relids, List* relids_list)
{
ListCell* lc = NULL;
foreach (lc, relids_list) {
if (bms_equal(relids, (Relids)lfirst(lc)))
return true;
}
return false;
}
* get_index_paths
* Given an index and a set of index clauses for it, construct IndexPaths.
*
* Plain indexpaths are sent directly to add_path, while potential
* bitmap indexpaths are added to *bitindexpaths for later processing.
*
* This is a fairly simple frontend to build_index_paths(). Its reason for
* existence is mainly to handle ScalarArrayOpExpr quals properly. If the
* index AM supports them natively, we should just include them in simple
* index paths. If not, we should exclude them while building simple index
* paths, and then make a separate attempt to include them in bitmap paths.
*/
static void get_index_paths(
PlannerInfo* root, RelOptInfo* rel, IndexOptInfo* index, IndexClauseSet* clauses, List** bitindexpaths)
{
List* indexpaths = NIL;
ListCell* lc = NULL;
* Build simple index paths using the clauses. Allow ScalarArrayOpExpr
* clauses only if the index AM supports them natively.
*/
indexpaths = build_index_paths(root, rel, index, clauses, index->predOK, SAOP_PER_AM, ST_ANYSCAN);
* Submit all the ones that can form plain IndexScan plans to add_path. (A
* plain IndexPath can represent either a plain IndexScan or an
* IndexOnlyScan, but for our purposes here that distinction does not
* matter. However, some of the indexes might support only bitmap scans,
* and those we mustn't submit to add_path here.)
*
* Also, pick out the ones that are usable as bitmap scans. For that, we
* must discard indexes that don't support bitmap scans, and we also are
* only interested in paths that have some selectivity; we should discard
* anything that was generated solely for ordering purposes.
*/
foreach (lc, indexpaths) {
IndexPath* ipath = (IndexPath*)lfirst(lc);
if (index->amhasgettuple)
add_path(root, rel, (Path*)ipath);
if (index->amhasgetbitmap && (ipath->path.pathkeys == NIL || ipath->indexselectivity < 1.0))
*bitindexpaths = lappend(*bitindexpaths, ipath);
}
* If the index doesn't handle ScalarArrayOpExpr clauses natively, check
* to see if there are any such clauses, and if so generate bitmap scan
* paths relying on executor-managed ScalarArrayOpExpr.
*/
if (!index->amsearcharray) {
indexpaths = build_index_paths(root, rel, index, clauses, false, SAOP_REQUIRE, ST_BITMAPSCAN);
*bitindexpaths = list_concat(*bitindexpaths, indexpaths);
}
}
static inline bool index_relation_has_bucket(IndexOptInfo* index)
{
Assert(index != NULL);
Oid heapOid = IndexGetRelation(index->indexoid, NoLock);
Relation rel = heap_open(heapOid, NoLock);
bool hasBucket = RELATION_HAS_BUCKET(rel);
heap_close(rel, NoLock);
return hasBucket;
}
inline bool IsEqRestrict(const RestrictInfo* rinfo)
{
Expr* clause = rinfo->clause;
return is_opclause(clause) && get_oprrest(((OpExpr*)clause)->opno) == EQSELRETURNOID;
}
* Check whether the indexqualcols in indexpath contain the given attNum and the
* constraint condition on this attNum is equality constraints.
*/
inline bool HasAttNumAndEqRestrict(const IndexPath* newPath, const int attNum)
{
ListCell* lc1 = NULL;
ListCell* lc2 = NULL;
IndexOptInfo* newPathIndex = (IndexOptInfo*)newPath->indexinfo;
forboth (lc1, newPath->indexqualcols, lc2, newPath->indexquals) {
int i = lfirst_int(lc1);
RestrictInfo* rinfo = (RestrictInfo*)lfirst(lc2);
if (newPathIndex->indexkeys[i] == attNum && IsEqRestrict(rinfo))
return true;
}
return false;
}
* Check whether index path contain all the index columns and the constraint conditions
* are equality constraints.
*/
inline bool ContainAllColsAndEqRestrict(const IndexPath* newPath, const IndexOptInfo* index)
{
for (int pos = 0; pos < index->ncolumns; pos++) {
if (!HasAttNumAndEqRestrict(newPath, index->indexkeys[pos]))
return false;
}
return true;
}
* For the given index, we want to mark whether the index contains the columns come from an
* unique index and the constraint conditions on these columns are equality constraints. This
* mark will be used in unique index first rule during path generation.
*/
void MarkUniqueIndexFirstRule(const RelOptInfo* rel, const IndexOptInfo* index, List* result)
{
if (!ENABLE_SQL_BETA_FEATURE(NO_UNIQUE_INDEX_FIRST) && OID_IS_BTREE(index->relam)) {
ListCell* lcr = NULL;
foreach (lcr, result) {
IndexPath* newPath = (IndexPath*)lfirst(lcr);
ListCell* lci = NULL;
foreach (lci, rel->indexlist) {
IndexOptInfo* indexToMatch = (IndexOptInfo*)lfirst(lci);
if (OID_IS_BTREE(indexToMatch->relam) && indexToMatch->unique &&
ContainAllColsAndEqRestrict(newPath, indexToMatch)) {
newPath->rulesforindexgen |= BTREE_INDEX_CONTAIN_UNIQUE_COLS;
break;
}
}
}
}
}
* build_index_paths
* Given an index and a set of index clauses for it, construct zero
* or more IndexPaths.
*
* We return a list of paths because (1) this routine checks some cases
* that should cause us to not generate any IndexPath, and (2) in some
* cases we want to consider both a forward and a backward scan, so as
* to obtain both sort orders. Note that the paths are just returned
* to the caller and not immediately fed to add_path().
*
* At top level, useful_predicate should be exactly the index's predOK flag
* (ie, true if it has a predicate that was proven from the restriction
* clauses). When working on an arm of an OR clause, useful_predicate
* should be true if the predicate required the current OR list to be proven.
* Note that this routine should never be called at all if the index has an
* unprovable predicate.
*
* saop_control indicates whether ScalarArrayOpExpr clauses can be used.
* When it's SAOP_REQUIRE, index paths are created only if we found at least
* one ScalarArrayOpExpr clause.
*
* scantype indicates whether we want to create plain indexscans, bitmap
* indexscans, or both. When it's ST_BITMAPSCAN, we will not consider
* index ordering while deciding if a Path is worth generating.
*
* 'rel' is the index's heap relation
* 'index' is the index for which we want to generate paths
* 'clauses' is the collection of indexable clauses (RestrictInfo nodes)
* 'useful_predicate' indicates whether the index has a useful predicate
* 'saop_control' indicates whether ScalarArrayOpExpr clauses can be used
* 'scantype' indicates whether we need plain or bitmap scan support
*/
static List* build_index_paths(PlannerInfo* root, RelOptInfo* rel, IndexOptInfo* index, IndexClauseSet* clauses,
bool useful_predicate, SaOpControl saop_control, ScanTypeControl scantype)
{
List* result = NIL;
IndexPath* ipath = NULL;
List* index_clauses = NIL;
List* clause_columns = NIL;
Relids outer_relids = NULL;
Bitmapset *upper_params = NULL;
double loop_count;
List* orderbyclauses = NIL;
List* orderbyclausecols = NIL;
List* index_pathkeys = NIL;
List* useful_pathkeys = NIL;
bool found_clause = false;
bool found_lower_saop_clause = false;
bool pathkeys_possibly_useful = false;
bool index_is_ordered = false;
bool index_only_scan = false;
int indexcol;
bool can_parallel = IS_STREAM_PLAN && (u_sess->opt_cxt.query_dop > 1) && (ST_BITMAPSCAN != scantype) &&
(!rel->isPartitionedTable) && !index->rel->is_ustore;
if (index->isAnnIndex && IsExtremeRedo()) {
if (ST_BITMAPSCAN != scantype) {
ereport(NOTICE, (errmsg("Ann Index does not support extreme RTO"),
errhint("This will show as Seq Scan")));
}
return NIL;
}
* Check that index supports the desired scan type(s)
*/
switch (scantype) {
case ST_INDEXSCAN:
if (!index->amhasgettuple)
return NIL;
break;
case ST_BITMAPSCAN:
if (!index->amhasgetbitmap)
return NIL;
break;
case ST_ANYSCAN:
break;
default:
break;
}
* 1. Collect the index clauses into a single list.
*
* We build a list of RestrictInfo nodes for clauses to be used with this
* index, along with an integer list of the index column numbers (zero
* based) that each clause should be used with. The clauses are ordered
* by index key, so that the column numbers form a nondecreasing sequence.
* (This order is depended on by btree and possibly other places.) The
* lists can be empty, if the index AM allows that.
*
* found_clause is set true only if there's at least one index clause; and
* if saop_control is SAOP_REQUIRE, it has to be a ScalarArrayOpExpr
* clause.
*
* found_lower_saop_clause is set true if there's a ScalarArrayOpExpr
* index clause for a non-first index column. This prevents us from
* assuming that the scan result is ordered. (Actually, the result is
* still ordered if there are equality constraints for all earlier
* columns, but it seems too expensive and non-modular for this code to be
* aware of that refinement.)
*
* We also build a Relids set showing which outer rels are required by the
* selected clauses.
*/
index_clauses = NIL;
clause_columns = NIL;
found_clause = false;
found_lower_saop_clause = false;
outer_relids = bms_copy(rel->lateral_relids);
for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++) {
ListCell* lc = NULL;
foreach (lc, clauses->indexclauses[indexcol]) {
RestrictInfo* rinfo = (RestrictInfo*)lfirst(lc);
if (IsA(rinfo->clause, ScalarArrayOpExpr)) {
if (saop_control == SAOP_PER_AM && !index->amsearcharray)
continue;
found_clause = true;
if (indexcol > 0)
found_lower_saop_clause = true;
} else {
if (saop_control != SAOP_REQUIRE)
found_clause = true;
}
index_clauses = lappend(index_clauses, rinfo);
clause_columns = lappend_int(clause_columns, indexcol);
outer_relids = bms_add_members(outer_relids, rinfo->clause_relids);
}
* If no clauses match the first index column, check for amoptionalkey
* restriction. We can't generate a scan over an index with
* amoptionalkey = false unless there's at least one index clause.
* (When working on columns after the first, this test cannot fail. It
* is always okay for columns after the first to not have any
* clauses.)
*/
if (index_clauses == NIL && !index->amoptionalkey)
return NIL;
}
outer_relids = bms_del_member(outer_relids, rel->relid);
if (bms_is_empty(outer_relids))
outer_relids = NULL;
loop_count = get_loop_count(root, outer_relids);
* 2. Compute pathkeys describing index's ordering, if any, then see how
* many of them are actually useful for this query. This is not relevant
* if we are only trying to build bitmap indexscans, nor if we have to
* assume the scan is unordered.
*/
pathkeys_possibly_useful =
(scantype != ST_BITMAPSCAN && !found_lower_saop_clause && has_useful_pathkeys(root, rel));
index_is_ordered = (index->sortopfamily != NULL);
if (index_is_ordered && pathkeys_possibly_useful) {
index_pathkeys = build_index_pathkeys(root, index, ForwardScanDirection);
useful_pathkeys = truncate_useless_pathkeys(root, rel, index_pathkeys);
orderbyclauses = NIL;
orderbyclausecols = NIL;
} else if (index->amcanorderbyop && pathkeys_possibly_useful) {
match_pathkeys_to_index(index, root->query_pathkeys, &orderbyclauses, &orderbyclausecols);
if (orderbyclauses != NULL)
useful_pathkeys = root->query_pathkeys;
else
useful_pathkeys = NIL;
} else {
useful_pathkeys = NIL;
orderbyclauses = NIL;
orderbyclausecols = NIL;
}
bool relHasbkt = false;
if (u_sess->attr.attr_sql.enable_hypo_index == false && index_relation_has_bucket(index)) {
relHasbkt = true;
}
* 3. Check if an index-only scan is possible. If we're not building
* plain indexscans, this isn't relevant since bitmap scans don't support
* index data retrieval anyway.
*/
index_only_scan = (scantype != ST_BITMAPSCAN && check_index_only(root, rel, index));
if (SUBQUERY_PREDPUSH(root)) {
upper_params = collect_param_clause((Node*)index_clauses);
}
* 4. Generate an indexscan path if there are relevant restriction clauses
* in the current clauses, OR the index ordering is potentially useful for
* later merging or final output ordering, OR the index has a useful
* predicate, OR an index-only scan is possible.
*/
if (found_clause || useful_pathkeys != NIL || useful_predicate || index_only_scan) {
if ((relHasbkt && !index->crossbucket)) {
useful_pathkeys = NIL;
}
ipath = create_index_path(root,
index,
index_clauses,
clause_columns,
orderbyclauses,
orderbyclausecols,
useful_pathkeys,
index_is_ordered ? ForwardScanDirection : NoMovementScanDirection,
index_only_scan,
outer_relids,
upper_params,
loop_count);
result = lappend(result, ipath);
if (can_parallel) {
ipath = create_index_path(root,
index,
index_clauses,
clause_columns,
NIL,
NIL,
useful_pathkeys,
index_is_ordered ? ForwardScanDirection : NoMovementScanDirection,
index_only_scan,
outer_relids,
upper_params,
loop_count,
u_sess->opt_cxt.query_dop);
result = lappend(result, ipath);
}
}
* 5. If the index is ordered, a backwards scan might be interesting.
*/
if (index_is_ordered && pathkeys_possibly_useful) {
index_pathkeys = build_index_pathkeys(root, index, BackwardScanDirection);
useful_pathkeys = truncate_useless_pathkeys(root, rel, index_pathkeys);
if (useful_pathkeys != NIL) {
if ((relHasbkt && !index->crossbucket)) {
useful_pathkeys = NIL;
}
ipath = create_index_path(root,
index,
index_clauses,
clause_columns,
NIL,
NIL,
useful_pathkeys,
BackwardScanDirection,
index_only_scan,
outer_relids,
upper_params,
loop_count);
result = lappend(result, ipath);
if (can_parallel) {
ipath = create_index_path(root,
index,
index_clauses,
clause_columns,
NIL,
NIL,
useful_pathkeys,
BackwardScanDirection,
index_only_scan,
outer_relids,
upper_params,
loop_count,
u_sess->opt_cxt.query_dop);
result = lappend(result, ipath);
}
}
}
* 6. Mark whether unique index fisrt rule satisfied in current btree index path.
* The rules will be used for selecting paths. We will check whether current index path
* contains a unique btree columns and the constraint conditions are equality constraints.
*/
MarkUniqueIndexFirstRule(rel, index, result);
return result;
}
* build_paths_for_OR
* Given a list of restriction clauses from one arm of an OR clause,
* construct all matching IndexPaths for the relation.
*
* Here we must scan all indexes of the relation, since a bitmap OR tree
* can use multiple indexes.
*
* The caller actually supplies two lists of restriction clauses: some
* "current" ones and some "other" ones. Both lists can be used freely
* to match keys of the index, but an index must use at least one of the
* "current" clauses to be considered usable. The motivation for this is
* examples like
* WHERE (x = 42) AND (... OR (y = 52 AND z = 77) OR ....)
* While we are considering the y/z subclause of the OR, we can use "x = 42"
* as one of the available index conditions; but we shouldn't match the
* subclause to any index on x alone, because such a Path would already have
* been generated at the upper level. So we could use an index on x,y,z
* or an index on x,y for the OR subclause, but not an index on just x.
* When dealing with a partial index, a match of the index predicate to
* one of the "current" clauses also makes the index usable.
*
* 'rel' is the relation for which we want to generate index paths
* 'clauses' is the current list of clauses (RestrictInfo nodes)
* 'other_clauses' is the list of additional upper-level clauses
*/
static List* build_paths_for_OR(
PlannerInfo* root, RelOptInfo* rel, List* clauses, List* other_clauses, IndexFeature idx_feature)
{
List* result = NIL;
List* all_clauses = NIL;
ListCell* lc = NULL;
foreach (lc, rel->indexlist) {
IndexOptInfo* index = (IndexOptInfo*)lfirst(lc);
IndexClauseSet clauseset;
List* indexpaths = NIL;
bool useful_predicate = false;
if (!index->amhasgetbitmap)
continue;
IndexFeature feature = getIndexFeature(index->isGlobal, index->crossbucket);
if (feature != idx_feature) {
continue;
}
* Build paths with global indexes only for un-bounded partition tables.
* The partition bounded tables should be handled by partition iterator
* or local indexes.
*/
RangeTblEntry* rte = planner_rt_fetch(rel->relid, root);
if (index->isGlobal && rte && list_length(rte->partitionOidList) > 0) {
continue;
}
* Ignore partial indexes that do not match the query. If a partial
* index is marked predOK then we know it's OK. Otherwise, we have to
* test whether the added clauses are sufficient to imply the
* predicate. If so, we can use the index in the current context.
*
* We set useful_predicate to true iff the predicate was proven using
* the current set of clauses. This is needed to prevent matching a
* predOK index to an arm of an OR, which would be a legal but
* pointlessly inefficient plan. (A better plan will be generated by
* just scanning the predOK index alone, no OR.)
*/
if (index->indpred != NIL) {
if (index->predOK) {
} else {
if (all_clauses == NIL)
all_clauses = list_concat(list_copy(clauses), other_clauses);
if (!predicate_implied_by(index->indpred, all_clauses))
continue;
if (!predicate_implied_by(index->indpred, other_clauses))
useful_predicate = true;
}
}
* Identify the restriction clauses that can match the index.
*/
errno_t errorno = EOK;
errorno = memset_s(&clauseset, sizeof(IndexClauseSet), 0, sizeof(clauseset));
securec_check(errorno, "\0", "\0");
match_clauses_to_index(index, clauses, &clauseset);
* If no matches so far, and the index predicate isn't useful, we
* don't want it.
*/
if (!clauseset.nonempty && !useful_predicate)
continue;
* Add "other" restriction clauses to the clauseset.
*/
match_clauses_to_index(index, other_clauses, &clauseset);
* Construct paths if possible.
*/
indexpaths = build_index_paths(root, rel, index, &clauseset, useful_predicate, SAOP_ALLOW, ST_BITMAPSCAN);
result = list_concat(result, indexpaths);
}
return result;
}
* generate_bitmap_or_paths
* Look through the list of clauses to find OR clauses, and generate
* a BitmapOrPath for each one we can handle that way. Return a list
* of the generated BitmapOrPaths.
*
* other_clauses is a list of additional clauses that can be assumed true
* for the purpose of generating indexquals, but are not to be searched for
* ORs. (See build_paths_for_OR() for motivation.)
*
* If restriction_only is true, ignore OR elements that are join clauses.
* When using this feature it is caller's responsibility that neither clauses
* nor other_clauses contain any join clauses that are not ORs, as we do not
* re-filter those lists.
*/
List* generate_bitmap_or_paths(
PlannerInfo* root, RelOptInfo* rel, List* clauses, List* other_clauses, bool restriction_only)
{
List* result = NIL;
List* all_clauses = NIL;
ListCell* lc = NULL;
* We can use both the current and other clauses as context for
* build_paths_for_OR; no need to remove ORs from the lists.
*/
all_clauses = list_concat(list_copy(clauses), other_clauses);
foreach (lc, clauses) {
RestrictInfo* rinfo = (RestrictInfo*)lfirst(lc);
List* pathlist = NIL;
Path* bitmapqual = NULL;
ListCell* j = NULL;
AssertEreport(IsA(rinfo, RestrictInfo), MOD_OPT, "Restriction clause is incorrect");
if (!restriction_is_or_clause(rinfo))
continue;
* We must be able to match at least one index to each of the arms of
* the OR, else we can't use it.
*/
pathlist = NIL;
foreach (j, ((BoolExpr*)rinfo->orclause)->args) {
Node* orarg = (Node*)lfirst(j);
List* indlist = NIL;
List* globalIndexList = NIL;
if (and_clause(orarg)) {
List* andargs = ((BoolExpr*)orarg)->args;
if (restriction_only)
andargs = drop_indexable_join_clauses(rel, andargs);
indlist = build_paths_for_OR(root, rel, andargs, all_clauses, NONFEATURED_INDEX);
indlist = list_concat(
indlist, generate_bitmap_or_paths(root, rel, andargs, all_clauses, restriction_only));
if (indlist == NIL) {
pathlist = NIL;
break;
}
IndexFeature indexFeature = getIndexFeature(rel->isPartitionedTable, (rel->bucketInfo != NULL));
if (indexFeature != NONFEATURED_INDEX) {
globalIndexList = build_paths_for_OR(root, rel, andargs, all_clauses, indexFeature);
globalIndexList = list_concat(globalIndexList,
GenerateBitmapOrPathsWithFeaturedIndex(root, rel, andargs, all_clauses, restriction_only,
indexFeature));
}
} else {
List* orargs = NIL;
AssertEreport(IsA(orarg, RestrictInfo), MOD_OPT, "Restriction clause is incorrect");
AssertEreport(restriction_is_or_clause((RestrictInfo*)orarg) == false,
MOD_OPT,
"Restriction clause does not contain OR");
orargs = list_make1(orarg);
if (restriction_only)
orargs = drop_indexable_join_clauses(rel, orargs);
indlist = build_paths_for_OR(root, rel, orargs, all_clauses, NONFEATURED_INDEX);
if (indlist == NIL) {
pathlist = NIL;
break;
}
IndexFeature indexFeature = getIndexFeature(rel->isPartitionedTable, (rel->bucketInfo != NULL));
if (indexFeature != NONFEATURED_INDEX) {
globalIndexList = build_paths_for_OR(root, rel, orargs, all_clauses, indexFeature);
}
}
* OK, pick the most promising AND combination, and add it to
* pathlist.
*/
bitmapqual = choose_bitmap_and(root, rel, indlist, globalIndexList);
pathlist = lappend(pathlist, bitmapqual);
}
* If we have a match for every arm, then turn them into a
* BitmapOrPath, and add to result list.
*/
if (pathlist != NIL) {
bitmapqual = (Path*)create_bitmap_or_path(root, rel, pathlist);
result = lappend(result, bitmapqual);
}
}
return result;
}
* GenerateBitmapOrPathsWithFeaturedIndex
* Generate BitmapOr paths With Special indexes,
* Look through the list of clauses to find OR clauses, and generate
* a BitmapOrPath for each one we can handle that way. Return a list
* of the generated BitmapOrPaths.
*
* other_clauses is a list of additional clauses that can be assumed true
* for the purpose of generating indexquals, but are not to be searched for
* ORs. (See build_paths_for_OR() for motivation.)
*
* If restriction_only is true, ignore OR elements that are join clauses.
* When using this feature it is caller's responsibility that neither clauses
* nor other_clauses contain any join clauses that are not ORs, as we do not
* re-filter those lists.
*
* Notes: For partition/hashbucket table and use featured index.
*/
List* GenerateBitmapOrPathsWithFeaturedIndex(PlannerInfo* root, RelOptInfo* rel, const List* clauses,
List* other_clauses, bool restriction_only, IndexFeature idx_feature)
{
List* result = NIL;
List* all_clauses = NIL;
ListCell* lc = NULL;
* We can use both the current and other clauses as context for
* build_paths_for_OR; no need to remove ORs from the lists.
*/
all_clauses = list_concat(list_copy(clauses), other_clauses);
foreach (lc, clauses) {
RestrictInfo* rinfo = (RestrictInfo*)lfirst(lc);
List* pathlist = NIL;
Path* bitmapqual = NULL;
ListCell* j = NULL;
AssertEreport(IsA(rinfo, RestrictInfo), MOD_OPT, "Restriction clause is incorrect");
if (!restriction_is_or_clause(rinfo))
continue;
* We must be able to match at least one index to each of the arms of
* the OR, else we can't use it.
*/
pathlist = NIL;
foreach (j, ((BoolExpr*)rinfo->orclause)->args) {
Node* orarg = (Node*)lfirst(j);
List* globalIndexList = NIL;
if (and_clause(orarg)) {
List* andargs = ((BoolExpr*)orarg)->args;
if (restriction_only)
andargs = drop_indexable_join_clauses(rel, andargs);
globalIndexList = build_paths_for_OR(root, rel, andargs, all_clauses, idx_feature);
globalIndexList = list_concat(
globalIndexList,
GenerateBitmapOrPathsWithFeaturedIndex(root, rel, andargs, all_clauses, restriction_only,
idx_feature));
} else {
List* orargs = NIL;
AssertEreport(IsA(orarg, RestrictInfo), MOD_OPT, "Restriction clause is incorrect");
AssertEreport(restriction_is_or_clause((RestrictInfo*)orarg) == false,
MOD_OPT,
"Restriction clause does not contain OR");
orargs = list_make1(orarg);
if (restriction_only)
orargs = drop_indexable_join_clauses(rel, orargs);
globalIndexList = build_paths_for_OR(root, rel, orargs, all_clauses, idx_feature);
}
* If nothing matched this arm, we can't do anything with this OR
* clause.
*/
if (globalIndexList == NIL) {
pathlist = NIL;
break;
}
* OK, pick the most promising AND combination, and add it to
* pathlist.
*/
bitmapqual = choose_bitmap_and(root, rel, globalIndexList, NIL);
pathlist = lappend(pathlist, bitmapqual);
}
* If we have a match for every arm, then turn them into a
* BitmapOrPath, and add to result list.
*/
if (pathlist != NIL) {
bitmapqual = (Path*)create_bitmap_or_path(root, rel, pathlist);
result = lappend(result, bitmapqual);
}
}
return result;
}
* drop_indexable_join_clauses
* Remove any indexable join clauses from the list.
*
* This is a helper for generate_bitmap_or_paths(). We leave OR clauses
* in the list whether they are joins or not, since we might be able to
* extract a restriction item from an OR list. It's safe to leave such
* clauses in the list because match_clauses_to_index() will ignore them,
* so there's no harm in passing such clauses to build_paths_for_OR().
*/
static List* drop_indexable_join_clauses(RelOptInfo* rel, List* clauses)
{
List* result = NIL;
ListCell* lc = NULL;
foreach (lc, clauses) {
RestrictInfo* rinfo = (RestrictInfo*)lfirst(lc);
AssertEreport(IsA(rinfo, RestrictInfo), MOD_OPT, "Restriction clause is incorrect");
if (restriction_is_or_clause(rinfo) || bms_is_subset(rinfo->clause_relids, rel->relids))
result = lappend(result, rinfo);
}
return result;
}
* As a heuristic, we first check for paths using exactly the same sets of
* WHERE clauses + index predicate conditions, and reject all but the
* cheapest-to-scan in any such group. This primarily gets rid of indexes
* that include the interesting columns but also irrelevant columns. (In
* situations where the DBA has gone overboard on creating variant
* indexes, this can make for a very large reduction in the number of
* paths considered further.)
*/
static PathClauseUsage** GetPathClauseUsage(List* paths, List* clauselist, int* npaths)
{
int tmpPaths = list_length(paths);
PathClauseUsage** pathinfoarray = NULL;
PathClauseUsage* pathinfo = NULL;
int i;
ListCell* l = NULL;
if (tmpPaths == 0) {
*npaths = 0;
return NULL;
}
pathinfoarray = (PathClauseUsage**)palloc(tmpPaths * sizeof(PathClauseUsage*));
tmpPaths = 0;
foreach (l, paths) {
Path* ipath = (Path*)lfirst(l);
pathinfo = classify_index_clause_usage(ipath, &clauselist);
for (i = 0; i < tmpPaths; i++) {
if (bms_equal(pathinfo->clauseids, pathinfoarray[i]->clauseids))
break;
}
if (i < tmpPaths) {
Cost ncost;
Cost ocost;
Selectivity nselec;
Selectivity oselec;
cost_bitmap_tree_node(pathinfo->path, &ncost, &nselec);
cost_bitmap_tree_node(pathinfoarray[i]->path, &ocost, &oselec);
if (ncost < ocost)
pathinfoarray[i] = pathinfo;
} else {
pathinfoarray[tmpPaths++] = pathinfo;
}
}
*npaths = tmpPaths;
return pathinfoarray;
}
* For each surviving index, consider it as an "AND group leader", and see
* whether adding on any of the later indexes results in an AND path with
* cheaper total cost than before. Then take the cheapest AND group.
*/
static void ChooseBitmapAndWithMultiIndex(
PlannerInfo* root, RelOptInfo* rel, ChooseBitmapAndInfo* chooseInfo, PathClauseUsage** pathInfos, int npaths)
{
PathClauseUsage* pathinfo = NULL;
ListCell* l = NULL;
for (int j = chooseInfo->startPath; j < npaths; j++) {
Cost newcost;
pathinfo = pathInfos[j];
if (bms_overlap(pathinfo->clauseids, chooseInfo->clauseidsofar))
continue;
if (pathinfo->preds != NIL) {
bool redundant = false;
foreach (l, pathinfo->preds) {
Node* np = (Node*)lfirst(l);
if (predicate_implied_by(list_make1(np), chooseInfo->qualsofar)) {
redundant = true;
break;
}
}
if (redundant)
continue;
}
chooseInfo->paths = lappend(chooseInfo->paths, pathinfo->path);
newcost = bitmap_and_cost_est(root, rel, chooseInfo->paths);
if (newcost < chooseInfo->costsofar || u_sess->attr.attr_sql.force_bitmapand) {
chooseInfo->costsofar = newcost;
chooseInfo->qualsofar = list_concat(chooseInfo->qualsofar, list_copy(pathinfo->quals));
chooseInfo->qualsofar = list_concat(chooseInfo->qualsofar, list_copy(pathinfo->preds));
chooseInfo->clauseidsofar = bms_add_members(chooseInfo->clauseidsofar, pathinfo->clauseids);
chooseInfo->lastcell = lnext(chooseInfo->lastcell);
} else {
chooseInfo->paths = list_delete_cell(chooseInfo->paths, lnext(chooseInfo->lastcell), chooseInfo->lastcell);
}
AssertEreport(lnext(chooseInfo->lastcell) == NULL, MOD_OPT, "Last cell is NULL");
}
}
* choose_bitmap_and
* Given a nonempty list of bitmap paths, AND them into one path.
*
* This is a nontrivial decision since we can legally use any subset of the
* given path set. We want to choose a good tradeoff between selectivity
* and cost of computing the bitmap.
*
* The result is either a single one of the inputs, or a BitmapAndPath
* combining multiple inputs.
*/
static Path* choose_bitmap_and(PlannerInfo* root, RelOptInfo* rel, List* paths, List* globalPartIndexPaths)
{
int npaths = list_length(paths);
PathClauseUsage** pathinfoarray;
PathClauseUsage* pathinfo = NULL;
List* clauselist = NIL;
List* bestpaths = NIL;
Cost bestcost = 0;
int i;
int globalPartPaths = list_length(globalPartIndexPaths);
PathClauseUsage** globalPathinfoarray;
AssertEreport(npaths > 0, MOD_OPT, "Path number is incorrect");
if (npaths == 1 && globalPartPaths == 0)
return (Path*)linitial(paths);
* In theory we should consider every nonempty subset of the given paths.
* In practice that seems like overkill, given the crude nature of the
* estimates, not to mention the possible effects of higher-level AND and
* OR clauses. Moreover, it's completely impractical if there are a large
* number of paths, since the work would grow as O(2^N).
*
* As a heuristic, we first check for paths using exactly the same sets of
* WHERE clauses + index predicate conditions, and reject all but the
* cheapest-to-scan in any such group. This primarily gets rid of indexes
* that include the interesting columns but also irrelevant columns. (In
* situations where the DBA has gone overboard on creating variant
* indexes, this can make for a very large reduction in the number of
* paths considered further.)
*
* We then sort the surviving paths with the cheapest-to-scan first, and
* for each path, consider using that path alone as the basis for a bitmap
* scan. Then we consider bitmap AND scans formed from that path plus
* each subsequent (higher-cost) path, adding on a subsequent path if it
* results in a reduction in the estimated total scan cost. This means we
* consider about O(N^2) rather than O(2^N) path combinations, which is
* quite tolerable, especially given than N is usually reasonably small
* because of the prefiltering step. The cheapest of these is returned.
*
* We will only consider AND combinations in which no two indexes use the
* same WHERE clause. This is a bit of a kluge: it's needed because
* costsize.c and clausesel.c aren't very smart about redundant clauses.
* They will usually double-count the redundant clauses, producing a
* too-small selectivity that makes a redundant AND step look like it
* reduces the total cost. Perhaps someday that code will be smarter and
* we can remove this limitation. (But note that this also defends
* against flat-out duplicate input paths, which can happen because
* match_join_clauses_to_index will find the same OR join clauses that
* extract_restriction_or_clauses has pulled OR restriction clauses out of.)
*
* For the same reason, we reject AND combinations in which an index
* predicate clause duplicates another clause. Here we find it necessary
* to be even stricter: we'll reject a partial index if any of its
* predicate clauses are implied by the set of WHERE clauses and predicate
* clauses used so far. This covers cases such as a condition "x = 42"
* used with a plain index, followed by a clauseless scan of a partial
* index "WHERE x >= 40 AND x < 50". The partial index has been accepted
* only because "x = 42" was present, and so allowing it would partially
* double-count selectivity. (We could use predicate_implied_by on
* regular qual clauses too, to have a more intelligent, but much more
* expensive, check for redundancy --- but in most cases simple equality
* seems to suffice.)
*/
* Extract clause usage info and detect any paths that use exactly the
* same set of clauses; keep only the cheapest-to-scan of any such groups.
* The surviving paths are put into an array for qsort'ing.
*/
pathinfoarray = GetPathClauseUsage(paths, clauselist, &npaths);;
globalPathinfoarray = GetPathClauseUsage(globalPartIndexPaths, clauselist, &globalPartPaths);
if (npaths == 1 && globalPartPaths == 0)
return pathinfoarray[0]->path;
qsort(pathinfoarray, npaths, sizeof(PathClauseUsage*), path_usage_comparator);
* For each surviving index, consider it as an "AND group leader", and see
* whether adding on any of the later indexes results in an AND path with
* cheaper total cost than before. Then take the cheapest AND group.
*/
for (i = 0; i < npaths; i++) {
ChooseBitmapAndInfo chooseInfo;
pathinfo = pathinfoarray[i];
chooseInfo.paths = list_make1(pathinfo->path);
chooseInfo.costsofar = bitmap_scan_cost_est(root, rel, pathinfo->path);
chooseInfo.qualsofar = list_concat(list_copy(pathinfo->quals), list_copy(pathinfo->preds));
chooseInfo.clauseidsofar = bms_copy(pathinfo->clauseids);
chooseInfo.startPath = i + 1;
chooseInfo.lastcell = list_head(chooseInfo.paths);
ChooseBitmapAndWithMultiIndex(root, rel, &chooseInfo, pathinfoarray, npaths);
* The local partition index and global partition index form bitmapAnd,
* the final result is the local partition index.
*
* Notes: For global partition index, the start judgment point is 0.
*/
if (globalPartPaths > 0) {
chooseInfo.startPath = 0;
ChooseBitmapAndWithMultiIndex(root, rel, &chooseInfo, globalPathinfoarray, globalPartPaths);
}
if (i == 0 || chooseInfo.costsofar < bestcost) {
bestpaths = chooseInfo.paths;
bestcost = chooseInfo.costsofar;
}
list_free_ext(chooseInfo.qualsofar);
if (u_sess->attr.attr_sql.force_bitmapand)
break;
}
if (list_length(bestpaths) == 1)
return (Path*)linitial(bestpaths);
return (Path*)create_bitmap_and_path(root, rel, bestpaths);
}
static int path_usage_comparator(const void* a, const void* b)
{
PathClauseUsage* pa = *(PathClauseUsage* const*)a;
PathClauseUsage* pb = *(PathClauseUsage* const*)b;
Cost acost;
Cost bcost;
Selectivity aselec;
Selectivity bselec;
cost_bitmap_tree_node(pa->path, &acost, &aselec);
cost_bitmap_tree_node(pb->path, &bcost, &bselec);
* If costs are the same, sort by selectivity.
*/
if (acost < bcost)
return -1;
if (acost > bcost)
return 1;
if (aselec < bselec)
return -1;
if (aselec > bselec)
return 1;
return 0;
}
* Estimate the cost of actually executing a bitmap scan with a single
* index path (no BitmapAnd, at least not at this level; but it could be
* a BitmapOr).
*/
static Cost bitmap_scan_cost_est(PlannerInfo* root, RelOptInfo* rel, Path* ipath)
{
BitmapHeapPath bpath;
Relids required_outer;
required_outer = get_bitmap_tree_required_outer(ipath);
bpath.path.type = T_BitmapHeapPath;
bpath.path.pathtype = T_BitmapHeapScan;
bpath.path.parent = rel;
bpath.path.pathtarget = rel->reltarget;
bpath.path.param_info = get_baserel_parampathinfo(root, rel, required_outer);
bpath.path.pathkeys = NIL;
bpath.bitmapqual = ipath;
cost_bitmap_heap_scan(&bpath.path, root, rel, bpath.path.param_info, ipath, get_loop_count(root, required_outer));
return bpath.path.total_cost;
}
* Estimate the cost of actually executing a BitmapAnd scan with the given
* inputs.
*/
static Cost bitmap_and_cost_est(PlannerInfo* root, RelOptInfo* rel, List* paths)
{
BitmapAndPath apath;
BitmapHeapPath bpath;
Relids required_outer;
apath.path.type = T_BitmapAndPath;
apath.path.pathtype = T_BitmapAnd;
apath.path.parent = rel;
bpath.path.pathtarget = rel->reltarget;
apath.path.param_info = NULL;
apath.path.pathkeys = NIL;
apath.bitmapquals = paths;
cost_bitmap_and_node(&apath, root);
required_outer = get_bitmap_tree_required_outer((Path*)&apath);
bpath.path.type = T_BitmapHeapPath;
bpath.path.pathtype = T_BitmapHeapScan;
bpath.path.parent = rel;
bpath.path.pathtarget = rel->reltarget;
bpath.path.param_info = get_baserel_parampathinfo(root, rel, required_outer);
bpath.path.pathkeys = NIL;
bpath.bitmapqual = (Path*)&apath;
cost_bitmap_heap_scan(
&bpath.path, root, rel, bpath.path.param_info, (Path*)&apath, get_loop_count(root, required_outer));
return bpath.path.total_cost;
}
* classify_index_clause_usage
* Construct a PathClauseUsage struct describing the WHERE clauses and
* index predicate clauses used by the given indexscan path.
* We consider two clauses the same if they are equal().
*
* At some point we might want to migrate this info into the Path data
* structure proper, but for the moment it's only needed
* within choose_bitmap_and().
*
* *clauselist is used and expanded as needed to identify all the distinct
* clauses seen across successive calls. Caller must initialize it to NIL
* before first call of a set.
*/
static PathClauseUsage* classify_index_clause_usage(Path* path, List** clauselist)
{
PathClauseUsage* result = NULL;
Bitmapset* clauseids = NULL;
ListCell* lc = NULL;
result = (PathClauseUsage*)palloc(sizeof(PathClauseUsage));
result->path = path;
result->quals = NIL;
result->preds = NIL;
find_indexpath_quals(path, &result->quals, &result->preds);
clauseids = NULL;
foreach (lc, result->quals) {
Node* node = (Node*)lfirst(lc);
clauseids = bms_add_member(clauseids, find_list_position(node, clauselist));
}
foreach (lc, result->preds) {
Node* node = (Node*)lfirst(lc);
clauseids = bms_add_member(clauseids, find_list_position(node, clauselist));
}
result->clauseids = clauseids;
return result;
}
* get_bitmap_tree_required_outer
* Find the required outer rels for a bitmap tree (index/and/or)
*
* We don't associate any particular parameterization with a BitmapAnd or
* BitmapOr node; however, the IndexPaths have parameterization info, in
* their capacity as standalone access paths. The parameterization required
* for the bitmap heap scan node is the union of rels referenced in the
* child IndexPaths.
*/
static Relids get_bitmap_tree_required_outer(Path* bitmapqual)
{
Relids result = NULL;
ListCell* lc = NULL;
if (IsA(bitmapqual, IndexPath)) {
return bms_copy(PATH_REQ_OUTER(bitmapqual));
} else if (IsA(bitmapqual, BitmapAndPath)) {
foreach (lc, ((BitmapAndPath*)bitmapqual)->bitmapquals) {
result = bms_join(result, get_bitmap_tree_required_outer((Path*)lfirst(lc)));
}
} else if (IsA(bitmapqual, BitmapOrPath)) {
foreach (lc, ((BitmapOrPath*)bitmapqual)->bitmapquals) {
result = bms_join(result, get_bitmap_tree_required_outer((Path*)lfirst(lc)));
}
} else {
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_UNRECOGNIZED_NODE_TYPE),
errmsg("unrecognized node type when find the required outer rels for a bitmap tree: %d",
nodeTag(bitmapqual))));
}
return result;
}
* get_bitmap_tree_required_upper
* Find the required outer rels which is outside of this query block
*/
static Bitmapset* get_bitmap_tree_required_upper(Path* bitmapqual)
{
Bitmapset* result = NULL;
ListCell* lc = NULL;
if (IsA(bitmapqual, IndexPath)) {
return bms_copy(PATH_REQ_UPPER(bitmapqual));
} else if (IsA(bitmapqual, BitmapAndPath)) {
foreach (lc, ((BitmapAndPath*)bitmapqual)->bitmapquals) {
result = bms_join(result, get_bitmap_tree_required_upper((Path*)lfirst(lc)));
}
} else if (IsA(bitmapqual, BitmapOrPath)) {
foreach (lc, ((BitmapOrPath*)bitmapqual)->bitmapquals) {
result = bms_join(result, get_bitmap_tree_required_upper((Path*)lfirst(lc)));
}
} else {
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_UNRECOGNIZED_NODE_TYPE),
errmsg("unrecognized node type when find the required upper rels for a bitmap tree: %d",
nodeTag(bitmapqual))));
}
return result;
}
* find_indexpath_quals
*
* Given the Path structure for a plain or bitmap indexscan, extract lists
* of all the indexquals and index predicate conditions used in the Path.
* These are appended to the initial contents of *quals and *preds (hence
* caller should initialize those to NIL).
*
* This is sort of a simplified version of make_restrictinfo_from_bitmapqual;
* here, we are not trying to produce an accurate representation of the AND/OR
* semantics of the Path, but just find out all the base conditions used.
*
* The result lists contain pointers to the expressions used in the Path,
* but all the list cells are freshly built, so it's safe to destructively
* modify the lists (eg, by concat'ing with other lists).
*/
static void find_indexpath_quals(Path* bitmapqual, List** quals, List** preds)
{
if (IsA(bitmapqual, BitmapAndPath)) {
BitmapAndPath* apath = (BitmapAndPath*)bitmapqual;
ListCell* l = NULL;
foreach (l, apath->bitmapquals) {
find_indexpath_quals((Path*)lfirst(l), quals, preds);
}
} else if (IsA(bitmapqual, BitmapOrPath)) {
BitmapOrPath* opath = (BitmapOrPath*)bitmapqual;
ListCell* l = NULL;
foreach (l, opath->bitmapquals) {
find_indexpath_quals((Path*)lfirst(l), quals, preds);
}
} else if (IsA(bitmapqual, IndexPath)) {
IndexPath* ipath = (IndexPath*)bitmapqual;
*quals = list_concat(*quals, get_actual_clauses(ipath->indexclauses));
*preds = list_concat(*preds, list_copy(ipath->indexinfo->indpred));
} else {
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_UNRECOGNIZED_NODE_TYPE),
errmsg("unrecognized node type when find indexpath quals: %d", nodeTag(bitmapqual))));
}
}
* find_list_position
* Return the given node's position (counting from 0) in the given
* list of nodes. If it's not equal() to any existing list member,
* add it at the end, and return that position.
*/
static int find_list_position(Node* node, List** nodelist)
{
int i;
ListCell* lc = NULL;
i = 0;
foreach (lc, *nodelist) {
Node* oldnode = (Node*)lfirst(lc);
if (equal(node, oldnode))
return i;
i++;
}
*nodelist = lappend(*nodelist, node);
return i;
}
* check_index_only
* Determine whether an index-only scan is possible for this index.
*/
static bool check_index_only(PlannerInfo* root, RelOptInfo* rel, IndexOptInfo* index)
{
bool result = false;
Bitmapset* attrs_used = NULL;
Bitmapset* index_attrs = NULL;
ListCell* lc = NULL;
int i;
List* hint = NIL;
hint = find_specific_scan_hint(root->parse->hintState, rel->relids, HINT_KEYWORD_INDEXONLYSCAN);
if (!u_sess->attr.attr_sql.enable_indexonlyscan && hint == NIL)
return false;
list_free_ext(hint);
if (!index->canreturn)
return false;
* Check that all needed attributes of the relation are available from the
* index.
*
* XXX this is overly conservative for partial indexes, since we will
* consider attributes involved in the index predicate as required even
* though the predicate won't need to be checked at runtime. (The same is
* true for attributes used only in index quals, if we are certain that
* the index is not lossy.) However, it would be quite expensive to
* determine that accurately at this point, so for now we take the easy
* way out.
*/
* Add all the attributes needed for joins or final output. Note: we must
* look at rel's targetlist, not the attr_needed data, because attr_needed
* isn't computed for inheritance child rels.
*/
pull_varattnos((Node*)rel->reltarget->exprs, rel->relid, &attrs_used);
foreach (lc, rel->baserestrictinfo) {
RestrictInfo* rinfo = (RestrictInfo*)lfirst(lc);
pull_varattnos((Node*)rinfo->clause, rel->relid, &attrs_used);
}
for (i = 0; i < index->ncolumns; i++) {
int attno = index->indexkeys[i];
* For the moment, we just ignore index expressions. It might be nice
* to do something with them, later.
*/
if (attno == 0)
continue;
index_attrs = bms_add_member(index_attrs, attno - FirstLowInvalidHeapAttributeNumber);
}
result = bms_is_subset(attrs_used, index_attrs);
bms_free_ext(attrs_used);
bms_free_ext(index_attrs);
return result;
}
* get_loop_count
* Choose the loop count estimate to use for costing a parameterized path
* with the given set of outer relids.
*
* Since we produce parameterized paths before we've begun to generate join
* relations, it's impossible to predict exactly how many times a parameterized
* path will be iterated; we don't know the size of the relation that will be
* on the outside of the nestloop. However, we should try to account for
* multiple iterations somehow in costing the path. The heuristic embodied
* here is to use the rowcount of the smallest other base relation needed in
* the join clauses used by the path. (We could alternatively consider the
* largest one, but that seems too optimistic.) This is of course the right
* answer for single-other-relation cases, and it seems like a reasonable
* zero-order approximation for multiway-join cases.
*
* Note: for this to work, allpaths.c must establish all baserel size
* estimates before it begins to compute paths, or at least before it
* calls create_index_paths().
*/
static double get_loop_count(PlannerInfo* root, Relids outer_relids)
{
double result = 1.0;
if (outer_relids != NULL) {
int relid;
outer_relids = bms_copy(outer_relids);
while ((relid = bms_first_member(outer_relids)) >= 0) {
RelOptInfo* outer_rel = NULL;
if (relid >= root->simple_rel_array_size)
continue;
outer_rel = root->simple_rel_array[relid];
if (outer_rel == NULL)
continue;
AssertEreport(outer_rel->relid == (uint)relid, MOD_OPT_JOIN, "Outer relid is inconsistent");
if (IS_DUMMY_REL(outer_rel))
continue;
if (!outer_rel->isPartitionedTable) {
AssertEreport(outer_rel->rows > 0, MOD_OPT_JOIN, "Outer rel row count is incorrect");
}
if (result == 1.0 || result > RELOPTINFO_LOCAL_FIELD(root, outer_rel, rows))
result = RELOPTINFO_LOCAL_FIELD(root, outer_rel, rows);
}
bms_free_ext(outer_relids);
}
return result;
}
* ---- ROUTINES TO CHECK QUERY CLAUSES ----
****************************************************************************/
* match_restriction_clauses_to_index
* Identify restriction clauses for the rel that match the index.
* Matching clauses are added to *clauseset.
*/
static void match_restriction_clauses_to_index(RelOptInfo* rel, IndexOptInfo* index, IndexClauseSet* clauseset)
{
match_clauses_to_index(index, rel->baserestrictinfo, clauseset);
}
* match_join_clauses_to_index
* Identify join clauses for the rel that match the index.
* Matching clauses are added to *clauseset.
* Also, add any potentially usable join OR clauses to *joinorclauses.
*/
static void match_join_clauses_to_index(
PlannerInfo* root, RelOptInfo* rel, IndexOptInfo* index,
IndexClauseSet* clauseset, List** joinorclauses)
{
ListCell* lc = NULL;
foreach (lc, rel->joininfo) {
RestrictInfo* rinfo = (RestrictInfo*)lfirst(lc);
if (!join_clause_is_movable_to(rinfo, rel))
continue;
if (restriction_is_or_clause(rinfo))
*joinorclauses = lappend(*joinorclauses, rinfo);
else
match_clause_to_index(index, rinfo, clauseset);
}
}
* match_eclass_clauses_to_index
* Identify EquivalenceClass join clauses for the rel that match the index.
* Matching clauses are added to *clauseset.
*/
static void match_eclass_clauses_to_index(PlannerInfo* root, IndexOptInfo* index, IndexClauseSet* clauseset)
{
int indexcol;
if (!index->rel->has_eclass_joins)
return;
for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++) {
List* clauses = NIL;
clauses = generate_implied_equalities_for_indexcol(root, index, indexcol, index->rel->lateral_referencers);
* We have to check whether the results actually do match the index,
* since for non-btree indexes the EC's equality operators might not
* be in the index opclass (cf eclass_member_matches_indexcol).
*/
match_clauses_to_index(index, clauses, clauseset);
}
}
* match_clauses_to_index
* Perform match_clause_to_index() for each clause in a list.
* Matching clauses are added to *clauseset.
*/
static void match_clauses_to_index(IndexOptInfo* index, List* clauses, IndexClauseSet* clauseset)
{
ListCell* lc = NULL;
foreach (lc, clauses) {
RestrictInfo* rinfo = (RestrictInfo*)lfirst(lc);
AssertEreport(IsA(rinfo, RestrictInfo), MOD_OPT, "Restriction clause is incorrect");
match_clause_to_index(index, rinfo, clauseset);
}
}
* match_clause_to_index
* Test whether a qual clause can be used with an index.
*
* If the clause is usable, add it to the appropriate list in *clauseset.
* *clauseset must be initialized to zeroes before first call.
*
* Note: in some circumstances we may find the same RestrictInfos coming from
* multiple places. Defend against redundant outputs by refusing to add a
* clause twice (pointer equality should be a good enough check for this).
*
* Note: it's possible that a badly-defined index could have multiple matching
* columns. We always select the first match if so; this avoids scenarios
* wherein we get an inflated idea of the index's selectivity by using the
* same clause multiple times with different index columns.
*/
static void match_clause_to_index(IndexOptInfo* index, RestrictInfo* rinfo, IndexClauseSet* clauseset)
{
int indexcol;
* Never match pseudoconstants to indexes. (Normally a match could not
* happen anyway, since a pseudoconstant clause couldn't contain a Var,
* but what if someone builds an expression index on a constant? It's not
* totally unreasonable to do so with a partial index, either.)
*/
if (rinfo->pseudoconstant)
return;
* If clause can't be used as an indexqual because it must wait till after
* some lower-security-level restriction clause, reject it.
*/
if (!restriction_is_securely_promotable(rinfo, index->rel))
return;
* The rel is column store but index qual not supported by vec engine
*/
if (index->rel->orientation == REL_COL_ORIENTED &&
vector_engine_unsupport_expression_walker((Node *)rinfo->clause)) {
return;
}
for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++) {
if (match_clause_to_indexcol(index, indexcol, rinfo)) {
clauseset->indexclauses[indexcol] = list_append_unique_ptr(clauseset->indexclauses[indexcol], rinfo);
clauseset->nonempty = true;
return;
}
}
}
* match_clause_to_indexcol
*
* Determines whether a restriction clause matches a column of an index.
*
* To match an index normally, the clause:
*
* (1) must be in the form (indexkey op const) or (const op indexkey);
* and
* (2) must contain an operator which is in the same family as the index
* operator for this column, or is a "special" operator as recognized
* by match_special_index_operator();
* and
* (3) must match the collation of the index, if collation is relevant.
*
* Our definition of "const" is exceedingly liberal: we allow anything that
* doesn't involve a volatile function or a Var of the index's relation.
* In particular, Vars belonging to other relations of the query are
* accepted here, since a clause of that form can be used in a
* parameterized indexscan. It's the responsibility of higher code levels
* to manage restriction and join clauses appropriately.
*
* Note: we do need to check for Vars of the index's relation on the
* "const" side of the clause, since clauses like (a.f1 OP (b.f2 OP a.f3))
* are not processable by a parameterized indexscan on a.f1, whereas
* something like (a.f1 OP (b.f2 OP c.f3)) is.
*
* Presently, the executor can only deal with indexquals that have the
* indexkey on the left, so we can only use clauses that have the indexkey
* on the right if we can commute the clause to put the key on the left.
* We do not actually do the commuting here, but we check whether a
* suitable commutator operator is available.
*
* If the index has a collation, the clause must have the same collation.
* For collation-less indexes, we assume it doesn't matter; this is
* necessary for cases like "hstore ? text", wherein hstore's operators
* don't care about collation but the clause will get marked with a
* collation anyway because of the text argument. (This logic is
* embodied in the macro IndexCollMatchesExprColl.)
*
* It is also possible to match RowCompareExpr clauses to indexes (but
* currently, only btree indexes handle this). In this routine we will
* report a match if the first column of the row comparison matches the
* target index column. This is sufficient to guarantee that some index
* condition can be constructed from the RowCompareExpr --- whether the
* remaining columns match the index too is considered in
* adjust_rowcompare_for_index.
*
* It is also possible to match ScalarArrayOpExpr clauses to indexes, when
* the clause is of the form "indexkey op ANY (arrayconst)".
*
* For boolean indexes, it is also possible to match the clause directly
* to the indexkey; or perhaps the clause is (NOT indexkey).
*
* 'index' is the index of interest.
* 'indexcol' is a column number of 'index' (counting from 0).
* 'rinfo' is the clause to be tested (as a RestrictInfo node).
*
* Returns true if the clause can be used with this index key.
*
* NOTE: returns false if clause is an OR or AND clause; it is the
* responsibility of higher-level routines to cope with those.
*/
static bool match_clause_to_indexcol(IndexOptInfo* index, int indexcol, RestrictInfo* rinfo)
{
Expr* clause = rinfo->clause;
Index index_relid = index->rel->relid;
Oid opfamily;
Oid idxcollation;
Node* leftop = NULL;
Node* rightop = NULL;
Relids left_relids;
Relids right_relids;
Oid expr_op;
Oid expr_coll;
bool plain_op = false;
bool isMatchPrefixKey = true;
Assert(indexcol < index->nkeycolumns);
opfamily = index->opfamily[indexcol];
idxcollation = index->indexcollations[indexcol];
* Never match pseudoconstants to indexes. (Normally this could not
* happen anyway, since a pseudoconstant clause couldn't contain a Var,
* but what if someone builds an expression index on a constant? It's not
* totally unreasonable to do so with a partial index, either.)
*/
if (rinfo->pseudoconstant)
return false;
if (IsBooleanOpfamily(opfamily)) {
if (match_boolean_index_clause((Node*)clause, indexcol, index))
return true;
}
* Clause must be a binary opclause, or possibly a ScalarArrayOpExpr
* (which is always binary, by definition). Or it could be a
* RowCompareExpr, which we pass off to match_rowcompare_to_indexcol().
* Or, if the index supports it, we can handle IS NULL/NOT NULL clauses.
*/
if (is_opclause(clause)) {
leftop = get_leftop(clause);
rightop = get_rightop(clause);
if (leftop == NULL || rightop == NULL)
return false;
left_relids = rinfo->left_relids;
right_relids = rinfo->right_relids;
expr_op = ((OpExpr*)clause)->opno;
expr_coll = ((OpExpr*)clause)->inputcollid;
plain_op = true;
} else if (clause && IsA(clause, ScalarArrayOpExpr)) {
ScalarArrayOpExpr* saop = (ScalarArrayOpExpr*)clause;
if (!saop->useOr)
return false;
leftop = (Node*)linitial(saop->args);
rightop = (Node*)lsecond(saop->args);
left_relids = NULL;
right_relids = pull_varnos(rightop);
expr_op = saop->opno;
expr_coll = saop->inputcollid;
plain_op = false;
isMatchPrefixKey = scalar_array_can_match_prefixkey(rightop);
} else if (clause && IsA(clause, RowCompareExpr)) {
return match_rowcompare_to_indexcol(index, indexcol, opfamily, idxcollation, (RowCompareExpr*)clause);
} else if (index->amsearchnulls && IsA(clause, NullTest)) {
NullTest* nt = (NullTest*)clause;
if (!nt->argisrow && match_index_to_operand((Node*)nt->arg, indexcol, index, true))
return true;
return false;
} else
return false;
* Check for clauses of the form: (indexkey operator constant) or
* (constant operator indexkey). See above notes about const-ness.
*/
if (match_index_to_operand(leftop, indexcol, index, isMatchPrefixKey) &&
!bms_is_member(index_relid, right_relids) && !contain_volatile_functions(rightop)) {
if (IndexCollMatchesExprColl(idxcollation, expr_coll) && is_indexable_operator(expr_op, opfamily, true))
return true;
* If we didn't find a member of the index's opfamily, see whether it
* is a "special" indexable operator.
*/
if (plain_op && match_special_index_operator(clause, opfamily, idxcollation, true, index, indexcol) &&
(IndexCollMatchesExprColl(idxcollation, expr_coll) ||
(!COLLATION_IN_B_FORMAT(idxcollation) && !COLLATION_IN_B_FORMAT(expr_coll)))) {
return true;
}
return false;
}
if (plain_op && match_index_to_operand(rightop, indexcol, index, isMatchPrefixKey) &&
!bms_is_member(index_relid, left_relids) && !contain_volatile_functions(leftop)) {
if (IndexCollMatchesExprColl(idxcollation, expr_coll) && is_indexable_operator(expr_op, opfamily, false))
return true;
* If we didn't find a member of the index's opfamily, see whether it
* is a "special" indexable operator.
*/
if (match_special_index_operator(clause, opfamily, idxcollation, false, index, indexcol) &&
(IndexCollMatchesExprColl(idxcollation, expr_coll) ||
(!COLLATION_IN_B_FORMAT(idxcollation) && !COLLATION_IN_B_FORMAT(expr_coll)))) {
return true;
}
return false;
}
return false;
}
* is_indexable_operator
* Does the operator match the specified index opfamily?
*
* If the indexkey is on the right, what we actually want to know
* is whether the operator has a commutator operator that matches
* the opfamily.
*/
static bool is_indexable_operator(Oid expr_op, Oid opfamily, bool indexkey_on_left)
{
if (!indexkey_on_left) {
expr_op = get_commutator(expr_op);
if (expr_op == InvalidOid)
return false;
}
if (expr_op == INT4EQOID && opfamily == INTEGER_BTREE_FAM_OID) {
return true;
}
return op_in_opfamily(expr_op, opfamily);
}
* match_rowcompare_to_indexcol
*
* Handles the RowCompareExpr case for match_clause_to_indexcol(),
* which see for comments.
*/
static bool match_rowcompare_to_indexcol(
IndexOptInfo* index, int indexcol, Oid opfamily, Oid idxcollation, RowCompareExpr* clause)
{
Index index_relid = index->rel->relid;
Node* leftop = NULL;
Node* rightop = NULL;
Oid expr_op;
Oid expr_coll;
if (!OID_IS_BTREE(index->relam))
return false;
* We could do the matching on the basis of insisting that the opfamily
* shown in the RowCompareExpr be the same as the index column's opfamily,
* but that could fail in the presence of reverse-sort opfamilies: it'd be
* a matter of chance whether RowCompareExpr had picked the forward or
* reverse-sort family. So look only at the operator, and match if it is
* a member of the index's opfamily (after commutation, if the indexkey is
* on the right). We'll worry later about whether any additional
* operators are matchable to the index.
*/
leftop = (Node*)linitial(clause->largs);
rightop = (Node*)linitial(clause->rargs);
expr_op = linitial_oid(clause->opnos);
expr_coll = linitial_oid(clause->inputcollids);
if (!IndexCollMatchesExprColl(idxcollation, expr_coll))
return false;
* These syntactic tests are the same as in match_clause_to_indexcol()
*/
if (match_index_to_operand(leftop, indexcol, index) && !bms_is_member(index_relid, pull_varnos(rightop)) &&
!contain_volatile_functions(rightop)) {
} else if (match_index_to_operand(rightop, indexcol, index) && !bms_is_member(index_relid, pull_varnos(leftop)) &&
!contain_volatile_functions(leftop)) {
expr_op = get_commutator(expr_op);
if (expr_op == InvalidOid)
return false;
} else
return false;
switch (get_op_opfamily_strategy(expr_op, opfamily)) {
case BTLessStrategyNumber:
case BTLessEqualStrategyNumber:
case BTGreaterEqualStrategyNumber:
case BTGreaterStrategyNumber:
return true;
default:
break;
}
return false;
}
* ---- ROUTINES TO CHECK ORDERING OPERATORS ----
****************************************************************************/
* match_pathkeys_to_index
* Test whether an index can produce output ordered according to the
* given pathkeys using "ordering operators".
*
* If it can, return a list of suitable ORDER BY expressions, each of the form
* "indexedcol operator pseudoconstant", along with an integer list of the
* index column numbers (zero based) that each clause would be used with.
* NIL lists are returned if the ordering is not achievable this way.
*
* On success, the result list is ordered by pathkeys, and in fact is
* one-to-one with the requested pathkeys.
*/
static void match_pathkeys_to_index(
IndexOptInfo* index, List* pathkeys, List** orderby_clauses_p, List** clause_columns_p)
{
List* orderby_clauses = NIL;
List* clause_columns = NIL;
ListCell* lc1 = NULL;
*orderby_clauses_p = NIL;
*clause_columns_p = NIL;
if (!index->amcanorderbyop)
return;
foreach (lc1, pathkeys) {
PathKey* pathkey = (PathKey*)lfirst(lc1);
bool found = false;
ListCell* lc2 = NULL;
* Note: for any failure to match, we just return NIL immediately.
* There is no value in matching just some of the pathkeys.
*/
if (index->relam == BM25_AM_OID) {
if (pathkey->pk_strategy != BTGreaterStrategyNumber) {
return;
}
} else if (pathkey->pk_strategy != BTLessStrategyNumber || pathkey->pk_nulls_first)
return;
if (pathkey->pk_eclass->ec_has_volatile)
return;
* Try to match eclass member expression(s) to index. Note that child
* EC members are considered, but only when they belong to the target
* relation. (Unlike regular members, the same expression could be a
* child member of more than one EC. Therefore, the same index could
* be considered to match more than one pathkey list, which is OK
* here. See also get_eclass_for_sort_expr.)
*/
foreach (lc2, pathkey->pk_eclass->ec_members) {
EquivalenceMember* member = (EquivalenceMember*)lfirst(lc2);
int indexcol;
if (!bms_equal(member->em_relids, index->rel->relids))
continue;
* We allow any column of the index to match each pathkey; they
* don't have to match left-to-right as you might expect. This is
* correct for GiST, which is the sole existing AM supporting
* amcanorderbyop. We might need different logic in future for
* other implementations.
*/
for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++) {
Expr* expr = NULL;
expr = match_clause_to_ordering_op(index, indexcol, member->em_expr, pathkey->pk_opfamily);
if (expr != NULL) {
orderby_clauses = lappend(orderby_clauses, expr);
clause_columns = lappend_int(clause_columns, indexcol);
found = true;
break;
}
}
if (found)
break;
}
if (!found)
return;
}
*orderby_clauses_p = orderby_clauses;
*clause_columns_p = clause_columns;
}
* match_clause_to_ordering_op
* Determines whether an ordering operator expression matches an
* index column.
*
* This is similar to, but simpler than, match_clause_to_indexcol.
* We only care about simple OpExpr cases. The input is a bare
* expression that is being ordered by, which must be of the form
* (indexkey op const) or (const op indexkey) where op is an ordering
* operator for the column's opfamily.
*
* 'index' is the index of interest.
* 'indexcol' is a column number of 'index' (counting from 0).
* 'clause' is the ordering expression to be tested.
* 'pk_opfamily' is the btree opfamily describing the required sort order.
*
* Note that we currently do not consider the collation of the ordering
* operator's result. In practical cases the result type will be numeric
* and thus have no collation, and it's not very clear what to match to
* if it did have a collation. The index's collation should match the
* ordering operator's input collation, not its result.
*
* If successful, return 'clause' as-is if the indexkey is on the left,
* otherwise a commuted copy of 'clause'. If no match, return NULL.
*/
static Expr* match_clause_to_ordering_op(IndexOptInfo* index, int indexcol, Expr* clause, Oid pk_opfamily)
{
Oid opfamily;
Oid idxcollation;
Node* leftop = NULL;
Node* rightop = NULL;
Oid expr_op;
Oid expr_coll;
Oid sortfamily;
bool commuted = false;
Assert(indexcol < index->nkeycolumns);
opfamily = index->opfamily[indexcol];
idxcollation = index->indexcollations[indexcol];
* Clause must be a binary opclause.
*/
if (!is_opclause(clause))
return NULL;
leftop = get_leftop(clause);
rightop = get_rightop(clause);
if (leftop == NULL || rightop == NULL)
return NULL;
expr_op = ((OpExpr*)clause)->opno;
expr_coll = ((OpExpr*)clause)->inputcollid;
* We can forget the whole thing right away if wrong collation.
*/
if (!IndexCollMatchesExprColl(idxcollation, expr_coll))
return NULL;
* Check for clauses of the form: (indexkey operator constant) or
* (constant operator indexkey).
*/
if (match_index_to_operand(leftop, indexcol, index) && !contain_var_clause(rightop) &&
!contain_volatile_functions(rightop)) {
commuted = false;
} else if (match_index_to_operand(rightop, indexcol, index) && !contain_var_clause(leftop) &&
!contain_volatile_functions(leftop)) {
expr_op = get_commutator(expr_op);
if (expr_op == InvalidOid)
return NULL;
commuted = true;
} else
return NULL;
* Is the (commuted) operator an ordering operator for the opfamily? And
* if so, does it yield the right sorting semantics?
*/
sortfamily = get_op_opfamily_sortfamily(expr_op, opfamily);
if (sortfamily != pk_opfamily)
return NULL;
if (commuted) {
OpExpr* newclause = makeNode(OpExpr);
errno_t rc = memcpy_s(newclause, sizeof(OpExpr), clause, sizeof(OpExpr));
securec_check(rc, "\0", "\0");
newclause->opno = expr_op;
newclause->opfuncid = InvalidOid;
newclause->args = list_make2(rightop, leftop);
clause = (Expr*)newclause;
}
return clause;
}
* ---- ROUTINES TO DO PARTIAL INDEX PREDICATE TESTS ----
****************************************************************************/
* check_partial_indexes
* Check each partial index of the relation, and mark it predOK if
* the index's predicate is satisfied for this query.
*
* Note: it is possible for this to get re-run after adding more restrictions
* to the rel; so we might be able to prove more indexes OK. We assume that
* adding more restrictions can't make an index not OK.
*/
void check_partial_indexes(PlannerInfo* root, RelOptInfo* rel)
{
List* clauselist = NIL;
bool have_partial = false;
Relids otherrels;
ListCell* lc = NULL;
* Frequently, there will be no partial indexes, so first check to make
* sure there's something useful to do here.
*/
have_partial = false;
foreach (lc, rel->indexlist) {
IndexOptInfo* index = (IndexOptInfo*)lfirst(lc);
if (index->indpred == NIL)
continue;
if (index->predOK)
continue;
have_partial = true;
break;
}
if (!have_partial)
return;
* Construct a list of clauses that we can assume true for the purpose
* of proving the index(es) usable. Restriction clauses for the rel are
* always usable, and so are any join clauses that are "movable to" this
* rel. Also, we can consider any EC-derivable join clauses (which must
* be "movable to" this rel, by definition).
*/
clauselist = list_copy(rel->baserestrictinfo);
foreach (lc, rel->joininfo) {
RestrictInfo* rinfo = (RestrictInfo*)lfirst(lc);
if (!join_clause_is_movable_to(rinfo, rel))
continue;
clauselist = lappend(clauselist, rinfo);
}
* Add on any equivalence-derivable join clauses. Computing the correct
* relid sets for generate_join_implied_equalities is slightly tricky
* because the rel could be a child rel rather than a true baserel, and
* in that case we must remove its parent's relid from all_baserels.
*/
if (rel->reloptkind == RELOPT_OTHER_MEMBER_REL) {
AppendRelInfo* appinfo = find_childrel_appendrelinfo(root, rel);
otherrels = bms_difference(root->all_baserels, bms_make_singleton(appinfo->parent_relid));
} else
otherrels = bms_difference(root->all_baserels, rel->relids);
if (!bms_is_empty(otherrels))
clauselist = list_concat(
clauselist, generate_join_implied_equalities(root, bms_union(rel->relids, otherrels), otherrels, rel));
foreach (lc, rel->indexlist) {
IndexOptInfo* index = (IndexOptInfo*)lfirst(lc);
if (index->indpred == NIL)
continue;
if (index->predOK)
continue;
if (ENABLE_CACHEDPLAN_MGR && root->glob->boundParams != NULL &&
root->glob->boundParams->uParamInfo == PARAM_VAL_SELECTIVITY_INFO){
root->glob->boundParams->params_lazy_bind = false;
clauselist = eval_const_clauses_params(root, clauselist);
root->glob->boundParams->params_lazy_bind = true;
}
index->predOK = predicate_implied_by(index->indpred, clauselist);
}
}
* ---- ROUTINES TO CHECK EXTERNALLY-VISIBLE CONDITIONS ----
****************************************************************************/
* eclass_member_matches_indexcol
* Test whether an EquivalenceClass member matches an index column.
*
* This is exported for use by generate_implied_equalities_for_indexcol.
*/
bool eclass_member_matches_indexcol(EquivalenceClass* ec, EquivalenceMember* em, IndexOptInfo* index, int indexcol)
{
Oid curFamily;
Oid curCollation;
Assert(indexcol < index->nkeycolumns);
curFamily = index->opfamily[indexcol];
curCollation = index->indexcollations[indexcol];
* If it's a btree index, we can reject it if its opfamily isn't
* compatible with the EC, since no clause generated from the EC could be
* used with the index. For non-btree indexes, we can't easily tell
* whether clauses generated from the EC could be used with the index, so
* don't check the opfamily. This might mean we return "true" for a
* useless EC, so we have to recheck the results of
* generate_implied_equalities_for_indexcol; see
* match_eclass_clauses_to_index.
*/
if (OID_IS_BTREE(index->relam) && !list_member_oid(ec->ec_opfamilies, curFamily))
return false;
if (!IndexCollMatchesExprColl(curCollation, ec->ec_collation))
return false;
return match_index_to_operand((Node*)em->em_expr, indexcol, index, true);
}
static bool relation_has_unique_index_for_no_index(PlannerInfo* root, RelOptInfo* rel)
{
if (u_sess->attr.attr_sql.enable_cluster_resize &&
strncmp(root->simple_rte_array[rel->relid]->relname,
REDIS_DELETE_DELTA_TABLE_PREFIX, strlen(REDIS_DELETE_DELTA_TABLE_PREFIX)) == 0) {
return true;
}
return false;
}
* relation_has_unique_index_for
* Determine whether the relation provably has at most one row satisfying
* a set of equality conditions, because the conditions constrain all
* columns of some unique index.
*
* The conditions can be represented in either or both of two ways:
* 1. A list of RestrictInfo nodes, where the caller has already determined
* that each condition is a mergejoinable equality with an expression in
* this relation on one side, and an expression not involving this relation
* on the other. The transient outer_is_left flag is used to identify which
* side we should look at: left side if outer_is_left is false, right side
* if it is true.
* 2. A list of expressions in this relation, and a corresponding list of
* equality operators. The caller must have already checked that the operators
* represent equality. (Note: the operators could be cross-type; the
* expressions should correspond to their RHS inputs.)
*
* The caller need only supply equality conditions arising from joins;
* this routine automatically adds in any usable baserestrictinfo clauses.
* (Note that the passed-in restrictlist will be destructively modified!)
*/
bool relation_has_unique_index_for(
PlannerInfo* root, RelOptInfo* rel, List* restrictlist, List* exprlist, List* oprlist)
{
ListCell* ic = NULL;
AssertEreport(
list_length(exprlist) == list_length(oprlist), MOD_OPT, "Exprlist and oprlist are not equal in length");
if (rel->indexlist == NIL) {
return relation_has_unique_index_for_no_index(root, rel);
}
* Examine the rel's restriction clauses for usable var = const clauses
* that we can add to the restrictlist.
*/
foreach (ic, rel->baserestrictinfo) {
RestrictInfo* restrictinfo = (RestrictInfo*)lfirst(ic);
* Note: can_join won't be set for a restriction clause, but
* mergeopfamilies will be if it has a mergejoinable operator and
* doesn't contain volatile functions.
*/
if (restrictinfo->mergeopfamilies == NIL)
continue;
* The clause certainly doesn't refer to anything but the given rel.
* If either side is pseudoconstant then we can use it.
*/
if (bms_is_empty(restrictinfo->left_relids)) {
restrictinfo->outer_is_left = true;
} else if (bms_is_empty(restrictinfo->right_relids)) {
restrictinfo->outer_is_left = false;
} else
continue;
restrictlist = lappend(restrictlist, restrictinfo);
}
if (restrictlist == NIL && exprlist == NIL)
return false;
foreach (ic, rel->indexlist) {
IndexOptInfo* ind = (IndexOptInfo*)lfirst(ic);
int c;
* If the index is not unique, or not immediately enforced, or if it's
* a partial index that doesn't match the query, it's useless here.
*/
if (!ind->unique || !ind->immediate || (ind->indpred != NIL && !ind->predOK))
continue;
* Try to find each index column in the lists of conditions. This is
* O(N^2) or worse, but we expect all the lists to be short.
*/
for (c = 0; c < ind->nkeycolumns; c++) {
bool matched = false;
ListCell* lc = NULL;
ListCell* lc2 = NULL;
foreach (lc, restrictlist) {
RestrictInfo* rinfo = (RestrictInfo*)lfirst(lc);
Node* rexpr = NULL;
* The condition's equality operator must be a member of the
* index opfamily, else it is not asserting the right kind of
* equality behavior for this index. We check this first
* since it's probably cheaper than match_index_to_operand().
*/
if (!list_member_oid(rinfo->mergeopfamilies, ind->opfamily[c]))
continue;
* XXX at some point we may need to check collations here too.
* For the moment we assume all collations reduce to the same
* notion of equality.
*/
if (rinfo->outer_is_left)
rexpr = get_rightop(rinfo->clause);
else
rexpr = get_leftop(rinfo->clause);
if (match_index_to_operand(rexpr, c, ind, true)) {
matched = true;
break;
}
}
if (matched)
continue;
forboth(lc, exprlist, lc2, oprlist)
{
Node* expr = (Node*)lfirst(lc);
Oid opr = lfirst_oid(lc2);
if (!match_index_to_operand(expr, c, ind, true))
continue;
* The equality operator must be a member of the index
* opfamily, else it is not asserting the right kind of
* equality behavior for this index. We assume the caller
* determined it is an equality operator, so we don't need to
* check any more tightly than this.
*/
if (!op_in_opfamily(opr, ind->opfamily[c]))
continue;
* XXX at some point we may need to check collations here too.
* For the moment we assume all collations reduce to the same
* notion of equality.
*/
matched = true;
break;
}
if (!matched)
break;
}
if (c == ind->nkeycolumns)
return true;
}
return false;
}
* ---- ROUTINES TO CHECK OPERANDS ----
****************************************************************************/
* match_index_to_operand
*
* Generalized test for a match between an index's key
* and the operand on one side of a restriction or join clause.
*
* operand: the nodetree to be compared to the index
* indexcol: the column number of the index (counting from 0)
* index: the index of interest
* match_prefixkey: if match prefix key to column
*
* Note that we aren't interested in collations here; the caller must check
* for a collation match, if it's dealing with an operator where that matters.
*
* This is exported for use in selfuncs.c.
*/
bool match_index_to_operand(Node* operand, int indexcol, IndexOptInfo* index, bool match_prefixkey)
{
int indkey;
* Ignore any RelabelType node above the operand. This is needed to be
* able to apply indexscanning in binary-compatible-operator cases. Note:
* we can assume there is at most one RelabelType node;
* eval_const_expressions() will have simplified if more than one.
*/
if (operand && IsA(operand, RelabelType))
operand = (Node*)((RelabelType*)operand)->arg;
indkey = index->indexkeys[indexcol];
if (indkey != 0) {
* Simple index column; operand must be a matching Var.
*/
if (operand && IsA(operand, Var) && index->rel->relid == ((Var*)operand)->varno &&
indkey == ((Var*)operand)->varattno)
return true;
} else {
* Index expression; find the correct expression. (This search could
* be avoided, at the cost of complicating all the callers of this
* routine; doesn't seem worth it.)
*/
ListCell* indexpr_item = NULL;
int i;
Node* indexkey = NULL;
indexpr_item = list_head(index->indexprs);
for (i = 0; i < indexcol; i++) {
if (index->indexkeys[i] == 0) {
if (indexpr_item == NULL)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg("wrong number of index expressions when match index to operand"))));
indexpr_item = lnext(indexpr_item);
}
}
if (indexpr_item == NULL)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg("wrong number of index expressions when match index to operand"))));
indexkey = (Node*)lfirst(indexpr_item);
* Does it match the operand? Again, strip any relabeling.
*/
if (indexkey && IsA(indexkey, RelabelType))
indexkey = (Node*)((RelabelType*)indexkey)->arg;
* PrefixKey is not a strict expression. It can be matched to column.
*/
if (match_prefixkey && PrefixKeyColumnMatched(indexkey, operand)) {
return true;
}
if (equal(indexkey, operand))
return true;
}
* if FuncExpr, check whether there are risks caused by type conversion.
*/
if (IsA(operand, FuncExpr))
check_report_cause_type((FuncExpr*)operand, indkey);
return false;
}
* ---- ROUTINES FOR "SPECIAL" INDEXABLE OPERATORS ----
****************************************************************************/
* These routines handle special optimization of operators that can be
* used with index scans even though they are not known to the executor's
* indexscan machinery. The key idea is that these operators allow us
* to derive approximate indexscan qual clauses, such that any tuples
* that pass the operator clause itself must also satisfy the simpler
* indexscan condition(s). Then we can use the indexscan machinery
* to avoid scanning as much of the table as we'd otherwise have to,
* while applying the original operator as a qpqual condition to ensure
* we deliver only the tuples we want. (In essence, we're using a regular
* index as if it were a lossy index.)
*
* An example of what we're doing is
* textfield LIKE 'abc%'
* from which we can generate the indexscanable conditions
* textfield >= 'abc' AND textfield < 'abd'
* which allow efficient scanning of an index on textfield.
* (In reality, character set and collation issues make the transformation
* from LIKE to indexscan limits rather harder than one might think ...
* but that's the basic idea.)
*
* Another thing that we do with this machinery is to provide special
* smarts for "boolean" indexes (that is, indexes on boolean columns
* that support boolean equality). We can transform a plain reference
* to the indexkey into "indexkey = true", or "NOT indexkey" into
* "indexkey = false", so as to make the expression indexable using the
* regular index operators. (As of Postgres 8.1, we must do this here
* because constant simplification does the reverse transformation;
* without this code there'd be no way to use such an index at all.)
*
* Three routines are provided here:
*
* match_special_index_operator() is just an auxiliary function for
* match_clause_to_indexcol(); after the latter fails to recognize a
* restriction opclause's operator as a member of an index's opfamily,
* it asks match_special_index_operator() whether the clause should be
* considered an indexqual anyway.
*
* match_boolean_index_clause() similarly detects clauses that can be
* converted into boolean equality operators.
*
* expand_indexqual_conditions() converts a list of RestrictInfo nodes
* (with implicit AND semantics across list elements) into a list of clauses
* that the executor can actually handle. For operators that are members of
* the index's opfamily this transformation is a no-op, but clauses recognized
* by match_special_index_operator() or match_boolean_index_clause() must be
* converted into one or more "regular" indexqual conditions.
*/
* match_boolean_index_clause
* Recognize restriction clauses that can be matched to a boolean index.
*
* This should be called only when IsBooleanOpfamily() recognizes the
* index's operator family. We check to see if the clause matches the
* index's key.
*/
static bool match_boolean_index_clause(Node* clause, int indexcol, IndexOptInfo* index)
{
if (match_index_to_operand(clause, indexcol, index))
return true;
if (not_clause(clause)) {
if (match_index_to_operand((Node*)get_notclausearg((Expr*)clause), indexcol, index)) {
return true;
}
} else if (clause && IsA(clause, BooleanTest)) {
* Since we only consider clauses at top level of WHERE, we can convert
* indexkey IS TRUE and indexkey IS FALSE to index searches as well. The
* different meaning for NULL isn't important.
*/
BooleanTest* btest = (BooleanTest*)clause;
if (btest->booltesttype == IS_TRUE || btest->booltesttype == IS_FALSE)
if (match_index_to_operand((Node*)btest->arg, indexcol, index))
return true;
}
return false;
}
static bool can_be_applyed_in_b_format(Oid idxcollation, IndexOptInfo* index, int indexcol)
{
if (!is_b_format_collation(idxcollation)) {
return false;
}
TargetEntry* tle = (TargetEntry*)list_nth(index->indextlist, indexcol);
bool hasPrefix = false;
bool hasLength = false;
if (IsA(tle->expr, PrefixKey)) {
hasPrefix = true;
} else if (IsA(tle->expr, Var)) {
Var *var = (Var *)tle->expr;
hasLength = var->vartypmod > 0;
}
return (hasLength || hasPrefix);
}
static bool is_valid_expr_like_op_in_b_format(Oid expr_op)
{
if (u_sess->attr.attr_sql.sql_compatibility != B_FORMAT) {
return false;
}
Oid binaryOid = get_typeoid(PG_CATALOG_NAMESPACE, "binary");
Oid varbinaryOid = get_typeoid(PG_CATALOG_NAMESPACE, "varbinary");
return (expr_op == OpernameGetOprid(list_make1(makeString("~~")), binaryOid, binaryOid) ||
expr_op == OpernameGetOprid(list_make1(makeString("~~")), varbinaryOid, varbinaryOid));
}
* match_special_index_operator
* Recognize restriction clauses that can be used to generate
* additional indexscanable qualifications.
*
* The given clause is already known to be a binary opclause having
* the form (indexkey OP pseudoconst) or (pseudoconst OP indexkey),
* but the OP proved not to be one of the index's opfamily operators.
* Return 'true' if we can do something with it anyway.
*/
static bool match_special_index_operator(Expr* clause,
Oid opfamily, Oid idxcollation, bool indexkey_on_left, IndexOptInfo* index, int indexcol)
{
bool isIndexable = false;
Node* rightop = NULL;
Oid expr_op;
Oid expr_coll;
Const* patt = NULL;
Const* prefix = NULL;
Pattern_Prefix_Status pstatus = Pattern_Prefix_None;
* Currently, all known special operators require the indexkey on the
* left, but this test could be pushed into the switch statement if some
* are added that do not...
*/
if (!indexkey_on_left) {
return false;
}
rightop = get_rightop(clause);
expr_op = ((OpExpr*)clause)->opno;
expr_coll = ((OpExpr*)clause)->inputcollid;
if (rightop == NULL || !IsA(rightop, Const) || ((Const*)rightop)->constisnull)
return false;
patt = (Const*)rightop;
switch (expr_op) {
case OID_TEXT_LIKE_OP:
case OID_BPCHAR_LIKE_OP:
case OID_NAME_LIKE_OP:
pstatus = pattern_fixed_prefix(patt, Pattern_Type_Like, expr_coll, &prefix, NULL);
isIndexable = (pstatus != Pattern_Prefix_None);
break;
case OID_BYTEA_LIKE_OP:
pstatus = pattern_fixed_prefix(patt, Pattern_Type_Like, expr_coll, &prefix, NULL);
isIndexable = (pstatus != Pattern_Prefix_None);
break;
case OID_TEXT_ICLIKE_OP:
case OID_BPCHAR_ICLIKE_OP:
case OID_NAME_ICLIKE_OP:
pstatus = pattern_fixed_prefix(patt, Pattern_Type_Like_IC, expr_coll, &prefix, NULL);
isIndexable = (pstatus != Pattern_Prefix_None);
break;
case OID_TEXT_REGEXEQ_OP:
case OID_BPCHAR_REGEXEQ_OP:
case OID_NAME_REGEXEQ_OP:
pstatus = pattern_fixed_prefix(patt, Pattern_Type_Regex, expr_coll, &prefix, NULL);
isIndexable = (pstatus != Pattern_Prefix_None);
break;
case OID_TEXT_ICREGEXEQ_OP:
case OID_BPCHAR_ICREGEXEQ_OP:
case OID_NAME_ICREGEXEQ_OP:
pstatus = pattern_fixed_prefix(patt, Pattern_Type_Regex_IC, expr_coll, &prefix, NULL);
isIndexable = (pstatus != Pattern_Prefix_None);
break;
case OID_INET_SUB_OP:
case OID_INET_SUBEQ_OP:
isIndexable = true;
break;
default:
if (is_valid_expr_like_op_in_b_format(expr_op)) {
pstatus = pattern_fixed_prefix(patt, Pattern_Type_Like, expr_coll, &prefix, NULL);
isIndexable = (pstatus != Pattern_Prefix_None);
}
break;
}
if (prefix != NULL) {
pfree(DatumGetPointer(prefix->constvalue));
pfree_ext(prefix);
}
if (!isIndexable) {
return false;
}
* Must also check that index's opfamily supports the operators we will
* want to apply. (A hash index, for example, will not support ">=".)
* Currently, only btree and spgist support the operators we need.
*
* Note: actually, in the Pattern_Prefix_Exact case, we only need "=" so a
* hash index would work. Currently it doesn't seem worth checking for
* that, however.
*
* We insist on the opfamily being the specific one we expect, else we'd
* do the wrong thing if someone were to make a reverse-sort opfamily with
* the same operators.
*
* The non-pattern opclasses will not sort the way we need in most non-C
* locales. We can use such an index anyway for an exact match (simple
* equality), but not for prefix-match cases. Note that here we are
* looking at the index's collation, not the expression's collation --
* this test is *not* dependent on the LIKE/regex operator's collation.
*/
switch (expr_op) {
case OID_TEXT_LIKE_OP:
case OID_TEXT_ICLIKE_OP:
case OID_TEXT_REGEXEQ_OP:
case OID_TEXT_ICREGEXEQ_OP:
isIndexable =
(opfamily == TEXT_PATTERN_BTREE_FAM_OID) || (opfamily == TEXT_SPGIST_FAM_OID) ||
(opfamily == TEXT_PATTERN_UBTREE_FAM_OID) ||
((opfamily == TEXT_BTREE_FAM_OID || opfamily == TEXT_UBTREE_FAM_OID) &&
(pstatus == Pattern_Prefix_Exact || lc_collate_is_c(idxcollation) ||
can_be_applyed_in_b_format(idxcollation, index, indexcol)));
break;
case OID_BPCHAR_LIKE_OP:
case OID_BPCHAR_ICLIKE_OP:
case OID_BPCHAR_REGEXEQ_OP:
case OID_BPCHAR_ICREGEXEQ_OP:
isIndexable = (opfamily == BPCHAR_PATTERN_BTREE_FAM_OID || opfamily == BPCHAR_PATTERN_UBTREE_FAM_OID) ||
((opfamily == BPCHAR_BTREE_FAM_OID || opfamily == BPCHAR_UBTREE_FAM_OID) &&
(pstatus == Pattern_Prefix_Exact || lc_collate_is_c(idxcollation)||
can_be_applyed_in_b_format(idxcollation, index, indexcol)));
break;
case OID_NAME_LIKE_OP:
case OID_NAME_ICLIKE_OP:
case OID_NAME_REGEXEQ_OP:
case OID_NAME_ICREGEXEQ_OP:
isIndexable = (opfamily == NAME_BTREE_FAM_OID || opfamily == NAME_UBTREE_FAM_OID);
break;
case OID_BYTEA_LIKE_OP:
isIndexable = (opfamily == BYTEA_BTREE_FAM_OID || opfamily == BYTEA_UBTREE_FAM_OID);
break;
case OID_INET_SUB_OP:
case OID_INET_SUBEQ_OP:
isIndexable = (opfamily == NETWORK_BTREE_FAM_OID || opfamily == NETWORK_UBTREE_FAM_OID);
break;
default:
if (is_valid_expr_like_op_in_b_format(expr_op)) {
isIndexable =
(OpfamilynameGetOpfid(BTREE_AM_OID, "binary_ops") == opfamily ||
OpfamilynameGetOpfid(BTREE_AM_OID, "varbinary_ops") == opfamily);
}
break;
}
return isIndexable;
}
* expand_indexqual_conditions
* Given a list of RestrictInfo nodes, produce a list of directly usable
* index qual clauses.
*
* Standard qual clauses (those in the index's opfamily) are passed through
* unchanged. Boolean clauses and "special" index operators are expanded
* into clauses that the indexscan machinery will know what to do with.
* RowCompare clauses are simplified if necessary to create a clause that is
* fully checkable by the index.
*
* In addition to the expressions themselves, there are auxiliary lists
* of the index column numbers that the clauses are meant to be used with;
* we generate an updated column number list for the result. (This is not
* the identical list because one input clause sometimes produces more than
* one output clause.)
*
* The input clauses are sorted by column number, and so the output is too.
* (This is depended on in various places in both planner and executor.)
*/
void expand_indexqual_conditions(
IndexOptInfo* index, List* indexclauses, List* indexclausecols, List** indexquals_p, List** indexqualcols_p)
{
List* indexquals = NIL;
List* indexqualcols = NIL;
ListCell* lcc = NULL;
ListCell* lci = NULL;
forboth(lcc, indexclauses, lci, indexclausecols)
{
RestrictInfo* rinfo = (RestrictInfo*)lfirst(lcc);
int indexcol = lfirst_int(lci);
Expr* clause = rinfo->clause;
Oid curFamily;
Oid curCollation;
Assert(indexcol < index->nkeycolumns);
curFamily = index->opfamily[indexcol];
curCollation = index->indexcollations[indexcol];
if (IsBooleanOpfamily(curFamily)) {
Expr* boolqual = NULL;
boolqual = expand_boolean_index_clause((Node*)clause, indexcol, index);
if (boolqual != NULL) {
indexquals = lappend(indexquals, make_simple_restrictinfo(boolqual));
indexqualcols = lappend_int(indexqualcols, indexcol);
continue;
}
}
* Else it must be an opclause (usual case), ScalarArrayOp,
* RowCompare, or NullTest
*/
if (is_opclause(clause)) {
indexquals = list_concat(indexquals,
expand_indexqual_opclause(index, rinfo, curFamily, curCollation, indexcol));
while (list_length(indexqualcols) < list_length(indexquals))
indexqualcols = lappend_int(indexqualcols, indexcol);
} else if (IsA(clause, ScalarArrayOpExpr)) {
indexquals = lappend(indexquals, expand_indexqual_scalar_array_op_expr(index, rinfo, curFamily, indexcol));
indexqualcols = lappend_int(indexqualcols, indexcol);
} else if (IsA(clause, RowCompareExpr)) {
indexquals = lappend(indexquals, expand_indexqual_rowcompare(rinfo, index, indexcol));
indexqualcols = lappend_int(indexqualcols, indexcol);
} else if (IsA(clause, NullTest)) {
Assert(index->amsearchnulls);
indexquals = lappend(indexquals, rinfo);
indexqualcols = lappend_int(indexqualcols, indexcol);
} else
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_UNRECOGNIZED_NODE_TYPE),
(errmsg("unsupported indexqual type when expand indexqual conditions: %d", (int)nodeTag(clause)))));
}
*indexquals_p = indexquals;
*indexqualcols_p = indexqualcols;
}
* expand_boolean_index_clause
* Convert a clause recognized by match_boolean_index_clause into
* a boolean equality operator clause.
*
* Returns NULL if the clause isn't a boolean index qual.
*/
static Expr* expand_boolean_index_clause(Node* clause, int indexcol, IndexOptInfo* index)
{
if (match_index_to_operand(clause, indexcol, index)) {
return make_opclause(BooleanEqualOperator,
BOOLOID,
false,
(Expr*)clause,
(Expr*)makeBoolConst(true, false),
InvalidOid,
InvalidOid);
}
if (not_clause(clause)) {
Node* arg = (Node*)get_notclausearg((Expr*)clause);
AssertEreport(match_index_to_operand(arg, indexcol, index), MOD_OPT, "Index key and operand are not matched");
return make_opclause(BooleanEqualOperator,
BOOLOID,
false,
(Expr*)arg,
(Expr*)makeBoolConst(false, false),
InvalidOid,
InvalidOid);
}
if (clause && IsA(clause, BooleanTest)) {
BooleanTest* btest = (BooleanTest*)clause;
Node* arg = (Node*)btest->arg;
AssertEreport(match_index_to_operand(arg, indexcol, index), MOD_OPT, "Index key and operand are not matched");
if (btest->booltesttype == IS_TRUE) {
return make_opclause(BooleanEqualOperator,
BOOLOID,
false,
(Expr*)arg,
(Expr*)makeBoolConst(true, false),
InvalidOid,
InvalidOid);
}
if (btest->booltesttype == IS_FALSE) {
return make_opclause(BooleanEqualOperator,
BOOLOID,
false,
(Expr*)arg,
(Expr*)makeBoolConst(false, false),
InvalidOid,
InvalidOid);
}
Assert(false);
}
return NULL;
}
* expand_indexqual_opclause --- expand a single indexqual condition
* that is an operator clause
*
* The input is a single RestrictInfo, the output a list of RestrictInfos.
*
* In the base case this is just list_make1(), but we have to be prepared to
* expand special cases that were accepted by match_special_index_operator().
*/
static List* expand_indexqual_opclause(IndexOptInfo* index, RestrictInfo* rinfo, Oid opfamily, Oid idxcollation,
int indexcol)
{
Expr* clause = rinfo->clause;
Node* leftop = get_leftop(clause);
Node* rightop = get_rightop(clause);
Oid expr_op = ((OpExpr*)clause)->opno;
Oid expr_coll = ((OpExpr*)clause)->inputcollid;
Const* patt = (Const*)rightop;
Const* prefix = NULL;
Pattern_Prefix_Status pstatus;
int prefixkey_len = get_index_column_prefix_lenth(index, indexcol);
if (patt == NULL) {
ereport(ERROR, (errmodule(MOD_OPT), errmsg("right operator can not be NULL")));
}
* LIKE and regex operators are not members of any btree index opfamily,
* but they can be members of opfamilies for more exotic index types such
* as GIN. Therefore, we should only do expansion if the operator is
* actually not in the opfamily. But checking that requires a syscache
* lookup, so it's best to first see if the operator is one we are
* interested in.
*/
switch (expr_op) {
case OID_TEXT_LIKE_OP:
case OID_BPCHAR_LIKE_OP:
case OID_NAME_LIKE_OP:
case OID_BYTEA_LIKE_OP:
if (!op_in_opfamily(expr_op, opfamily)) {
pstatus = pattern_fixed_prefix(patt, Pattern_Type_Like, expr_coll, &prefix, NULL);
return prefix_quals_with_encdoing(leftop, opfamily, idxcollation, prefix, pstatus, prefixkey_len);
}
break;
case OID_TEXT_ICLIKE_OP:
case OID_BPCHAR_ICLIKE_OP:
case OID_NAME_ICLIKE_OP:
if (!op_in_opfamily(expr_op, opfamily)) {
pstatus = pattern_fixed_prefix(patt, Pattern_Type_Like_IC, expr_coll, &prefix, NULL);
return prefix_quals_with_encdoing(leftop, opfamily, idxcollation, prefix, pstatus, prefixkey_len);
}
break;
case OID_TEXT_REGEXEQ_OP:
case OID_BPCHAR_REGEXEQ_OP:
case OID_NAME_REGEXEQ_OP:
if (!op_in_opfamily(expr_op, opfamily)) {
pstatus = pattern_fixed_prefix(patt, Pattern_Type_Regex, expr_coll, &prefix, NULL);
return prefix_quals_with_encdoing(leftop, opfamily, idxcollation, prefix, pstatus, prefixkey_len);
}
break;
case OID_TEXT_ICREGEXEQ_OP:
case OID_BPCHAR_ICREGEXEQ_OP:
case OID_NAME_ICREGEXEQ_OP:
if (!op_in_opfamily(expr_op, opfamily)) {
pstatus = pattern_fixed_prefix(patt, Pattern_Type_Regex_IC, expr_coll, &prefix, NULL);
return prefix_quals_with_encdoing(leftop, opfamily, idxcollation, prefix, pstatus, prefixkey_len);
}
break;
case OID_INET_SUB_OP:
case OID_INET_SUBEQ_OP:
if (!op_in_opfamily(expr_op, opfamily)) {
return network_prefix_quals(leftop, expr_op, opfamily, patt->constvalue);
}
break;
default:
if (prefixkey_len > 0 && op_in_opfamily(expr_op, opfamily)) {
return list_make1(rewrite_opclause_for_prefixkey(rinfo, index, opfamily, prefixkey_len));
}
if (is_valid_expr_like_op_in_b_format(expr_op)) {
pstatus = pattern_fixed_prefix(patt, Pattern_Type_Like, expr_coll, &prefix, NULL);
return prefix_quals_with_encdoing(leftop, opfamily, idxcollation, prefix, pstatus, prefixkey_len);
}
break;
}
return list_make1(rinfo);
}
* expand_indexqual_rowcompare --- expand a single indexqual condition
* that is a RowCompareExpr
*
* This is a thin wrapper around adjust_rowcompare_for_index; we export the
* latter so that createplan.c can use it to re-discover which columns of the
* index are used by a row comparison indexqual.
*/
static RestrictInfo* expand_indexqual_rowcompare(RestrictInfo* rinfo, IndexOptInfo* index, int indexcol)
{
RowCompareExpr* clause = (RowCompareExpr*)rinfo->clause;
Expr* newclause = NULL;
List* indexcolnos = NIL;
bool var_on_left = false;
newclause = adjust_rowcompare_for_index(clause, index, indexcol, &indexcolnos, &var_on_left);
AssertEreport(newclause != NULL, MOD_OPT, "Newclause can not be NULL");
* If we didn't have to change the RowCompareExpr, return the original
* RestrictInfo.
*/
if (newclause == (Expr*)clause)
return rinfo;
return make_simple_restrictinfo(newclause);
}
* adjust_rowcompare_for_index --- expand a single indexqual condition
* that is a RowCompareExpr
*
* It's already known that the first column of the row comparison matches
* the specified column of the index. We can use additional columns of the
* row comparison as index qualifications, so long as they match the index
* in the "same direction", ie, the indexkeys are all on the same side of the
* clause and the operators are all the same-type members of the opfamilies.
* If all the columns of the RowCompareExpr match in this way, we just use it
* as-is. Otherwise, we build a shortened RowCompareExpr (if more than one
* column matches) or a simple OpExpr (if the first-column match is all
* there is). In these cases the modified clause is always "<=" or ">="
* even when the original was "<" or ">" --- this is necessary to match all
* the rows that could match the original. (We are essentially building a
* lossy version of the row comparison when we do this.)
*
* *indexcolnos receives an integer list of the index column numbers (zero
* based) used in the resulting expression. The reason we need to return
* that is that if the index is selected for use, createplan.c will need to
* call this again to extract that list. (This is a bit grotty, but row
* comparison indexquals aren't used enough to justify finding someplace to
* keep the information in the Path representation.) Since createplan.c
* also needs to know which side of the RowCompareExpr is the index side,
* we also return *var_on_left_p rather than re-deducing that there.
*/
Expr* adjust_rowcompare_for_index(
RowCompareExpr* clause, IndexOptInfo* index, int indexcol, List** indexcolnos, bool* var_on_left_p)
{
bool var_on_left = false;
int op_strategy;
Oid op_lefttype;
Oid op_righttype;
int matching_cols;
Oid expr_op;
List* opfamilies = NIL;
List* lefttypes = NIL;
List* righttypes = NIL;
List* new_ops = NIL;
ListCell* largs_cell = NULL;
ListCell* rargs_cell = NULL;
ListCell* opnos_cell = NULL;
ListCell* collids_cell = NULL;
var_on_left = match_index_to_operand((Node*)linitial(clause->largs), indexcol, index);
AssertEreport(var_on_left == true || match_index_to_operand((Node*)linitial(clause->rargs), indexcol, index),
MOD_OPT,
"index key and operand are mismatched on either left or right");
*var_on_left_p = var_on_left;
expr_op = linitial_oid(clause->opnos);
if (!var_on_left)
expr_op = get_commutator(expr_op);
get_op_opfamily_properties(expr_op, index->opfamily[indexcol], false, &op_strategy, &op_lefttype, &op_righttype);
*indexcolnos = list_make1_int(indexcol);
opfamilies = list_make1_oid(index->opfamily[indexcol]);
lefttypes = list_make1_oid(op_lefttype);
righttypes = list_make1_oid(op_righttype);
* See how many of the remaining columns match some index column in the
* same way. As in match_clause_to_indexcol(), the "other" side of any
* potential index condition is OK as long as it doesn't use Vars from the
* indexed relation.
*/
matching_cols = 1;
largs_cell = lnext(list_head(clause->largs));
rargs_cell = lnext(list_head(clause->rargs));
opnos_cell = lnext(list_head(clause->opnos));
collids_cell = lnext(list_head(clause->inputcollids));
while (largs_cell != NULL) {
Node* varop = NULL;
Node* constop = NULL;
int i;
expr_op = lfirst_oid(opnos_cell);
if (var_on_left) {
varop = (Node*)lfirst(largs_cell);
constop = (Node*)lfirst(rargs_cell);
} else {
varop = (Node*)lfirst(rargs_cell);
constop = (Node*)lfirst(largs_cell);
expr_op = get_commutator(expr_op);
if (expr_op == InvalidOid)
break;
}
if (bms_is_member(index->rel->relid, pull_varnos(constop)))
break;
if (contain_volatile_functions(constop))
break;
* The Var side can match any column of the index.
*/
for (i = 0; i < index->nkeycolumns; i++) {
if (match_index_to_operand(varop, i, index) &&
get_op_opfamily_strategy(expr_op, index->opfamily[i]) == op_strategy &&
IndexCollMatchesExprColl(index->indexcollations[i], lfirst_oid(collids_cell)))
break;
}
if (i >= index->nkeycolumns)
break;
*indexcolnos = lappend_int(*indexcolnos, i);
get_op_opfamily_properties(expr_op, index->opfamily[i], false, &op_strategy, &op_lefttype, &op_righttype);
opfamilies = lappend_oid(opfamilies, index->opfamily[i]);
lefttypes = lappend_oid(lefttypes, op_lefttype);
righttypes = lappend_oid(righttypes, op_righttype);
matching_cols++;
largs_cell = lnext(largs_cell);
rargs_cell = lnext(rargs_cell);
opnos_cell = lnext(opnos_cell);
collids_cell = lnext(collids_cell);
}
if (matching_cols == list_length(clause->opnos))
return (Expr*)clause;
* We have to generate a subset rowcompare (possibly just one OpExpr). The
* painful part of this is changing < to <= or > to >=, so deal with that
* first.
*/
if (op_strategy == BTLessEqualStrategyNumber || op_strategy == BTGreaterEqualStrategyNumber) {
new_ops = list_truncate(list_copy(clause->opnos), matching_cols);
} else {
ListCell* opfamilies_cell = NULL;
ListCell* lefttypes_cell = NULL;
ListCell* righttypes_cell = NULL;
if (op_strategy == BTLessStrategyNumber)
op_strategy = BTLessEqualStrategyNumber;
else if (op_strategy == BTGreaterStrategyNumber)
op_strategy = BTGreaterEqualStrategyNumber;
else
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg("unexpected strategy number %d when expand a single indexqual condition", op_strategy))));
new_ops = NIL;
lefttypes_cell = list_head(lefttypes);
righttypes_cell = list_head(righttypes);
foreach (opfamilies_cell, opfamilies) {
Oid opfam = lfirst_oid(opfamilies_cell);
Oid lefttype = lfirst_oid(lefttypes_cell);
Oid righttype = lfirst_oid(righttypes_cell);
expr_op = get_opfamily_member(opfam, lefttype, righttype, op_strategy);
if (!OidIsValid(expr_op))
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg(
"when expand a single indexqual condition could not find member %d(%u,%u) of opfamily %u",
op_strategy,
lefttype,
righttype,
opfam))));
if (!var_on_left) {
expr_op = get_commutator(expr_op);
if (!OidIsValid(expr_op))
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_INVALID_OPERATION),
(errmsg("when expand a single indexqual condition could not find commutator of member "
"%d(%u,%u) of opfamily %u",
op_strategy,
lefttype,
righttype,
opfam))));
}
new_ops = lappend_oid(new_ops, expr_op);
lefttypes_cell = lnext(lefttypes_cell);
righttypes_cell = lnext(righttypes_cell);
}
}
if (matching_cols > 1) {
RowCompareExpr* rc = makeNode(RowCompareExpr);
if (var_on_left)
rc->rctype = (RowCompareType)op_strategy;
else
rc->rctype = (op_strategy == BTLessEqualStrategyNumber) ? ROWCOMPARE_GE : ROWCOMPARE_LE;
rc->opnos = new_ops;
rc->opfamilies = list_truncate(list_copy(clause->opfamilies), matching_cols);
rc->inputcollids = list_truncate(list_copy(clause->inputcollids), matching_cols);
rc->largs = list_truncate((List*)copyObject(clause->largs), matching_cols);
rc->rargs = list_truncate((List*)copyObject(clause->rargs), matching_cols);
return (Expr*)rc;
} else {
return make_opclause(linitial_oid(new_ops),
BOOLOID,
false,
(Expr*)copyObject(linitial(clause->largs)),
(Expr*)copyObject(linitial(clause->rargs)),
InvalidOid,
linitial_oid(clause->inputcollids));
}
}
static PadContent get_pad_content(Oid collation)
{
unsigned long int maxSortCode;
unsigned long int minSortCode;
PadContent content;
switch (collation) {
case GBK_CHINESE_CI_COLLATION_OID: {
maxSortCode = 0xA967;
minSortCode = 0;
content.minBufLen = 1;
content.minSortBuf[0] = 0;
content.maxBufLen = 2;
content.maxSortBuf[0] = (char)(maxSortCode >> 8);
content.maxSortBuf[1] = maxSortCode & 0xFF;
break;
}
case GBK_BIN_COLLATION_OID: {
maxSortCode = 0xFEFE;
minSortCode = 0;
content.minBufLen = 1;
content.minSortBuf[0] = 0;
content.maxBufLen = 2;
content.maxSortBuf[0] = (char)(maxSortCode >> 8);
content.maxSortBuf[1] = maxSortCode & 0xFF;
break;
}
case UTF8_UNICODE_CI_COLLATION_OID:
case UTF8MB4_UNICODE_CI_COLLATION_OID: {
maxSortCode = 0xFFFF;
minSortCode = 0;
content.minBufLen = 1;
content.minSortBuf[0] = 9;
content.maxBufLen = 3;
content.maxSortBuf[2] = (unsigned char) (0x80 | (maxSortCode & 0x3f));
maxSortCode = maxSortCode >> 6;
maxSortCode |= 0x800;
content.maxSortBuf[1] = (unsigned char) (0x80 | (maxSortCode & 0x3f));
maxSortCode = maxSortCode >> 6;
maxSortCode |= 0xc0;
content.maxSortBuf[0] = (unsigned char)maxSortCode;
break;
}
case UTF8MB4_GENERAL_CI_COLLATION_OID:
case UTF8MB4_BIN_COLLATION_OID:
case UTF8_GENERAL_CI_COLLATION_OID:
case UTF8_BIN_COLLATION_OID: {
maxSortCode = 0xFFFF;
minSortCode = 0;
content.minBufLen = 1;
content.minSortBuf[0] = 0;
content.maxBufLen = 3;
content.maxSortBuf[2] = (unsigned char) (0x80 | (maxSortCode & 0x3f));
maxSortCode = maxSortCode >> 6;
maxSortCode |= 0x800;
content.maxSortBuf[1] = (unsigned char) (0x80 | (maxSortCode & 0x3f));
maxSortCode = maxSortCode >> 6;
maxSortCode |= 0xc0;
content.maxSortBuf[0] = (unsigned char)maxSortCode;
break;
}
case GB18030_CHINESE_CI_COLLATION_OID: {
maxSortCode = 0xFE39FE39;
content.minBufLen = 1;
content.minSortBuf[0] = 0;
content.maxSortBuf[0] = (maxSortCode >> 24) & 0xFF;
content.maxSortBuf[1] = (maxSortCode >> 16) & 0xFF;
content.maxSortBuf[2] = (maxSortCode >> 8) & 0xFF;
content.maxSortBuf[3] = maxSortCode & 0xFF;
content.maxBufLen = 4;
break;
}
case GB18030_BIN_COLLATION_OID: {
maxSortCode = 0xFEFEFEFE;
content.minBufLen = 1;
content.minSortBuf[0] = 0;
content.maxSortBuf[0] = (maxSortCode >> 24) & 0xFF;
content.maxSortBuf[1] = (maxSortCode >> 16) & 0xFF;
content.maxSortBuf[2] = (maxSortCode >> 8) & 0xFF;
content.maxSortBuf[3] = maxSortCode & 0xFF;
content.maxBufLen = 4;
break;
}
default:
ereport(ERROR, (errmodule(MOD_OPT), errcode(ERRCODE_CASE_NOT_FOUND),
(errmsg(
"Invalid collation oid during getting prefix quals in B format"))));
break;
}
return content;
}
static int get_pad_length(Node* leftop, int prefixLen)
{
int len;
switch (nodeTag(leftop)) {
case T_Var: {
Var *var = (Var *)leftop;
len = var->vartypmod;
break;
}
case T_RelabelType: {
RelabelType *expr = (RelabelType *)leftop;
Var *var = (Var *)expr->arg;
len = var->vartypmod;
break;
}
default:
return 0;
}
if (len < 0) {
return prefixLen;
} else {
len -= VARHDRSZ;
if (prefixLen <= 0) {
return len;
}
return (len < prefixLen) ? len : prefixLen;
}
}
static Const* pad_string_in_like(PadContent content, const Const* strConst, int length, bool isPadMax)
{
if (length <= 0) {
return NULL;
}
Oid datatype = strConst->consttype;
char* workstr = NULL;
workstr = TextDatumGetCString(strConst->constvalue);
int curLen = strlen(workstr);
char* buf = isPadMax ? content.maxSortBuf : content.minSortBuf;
int buflen = isPadMax ? content.maxBufLen : content.minBufLen;
int padLen = length - pg_mbstrlen_with_len(workstr, curLen);
* we don't generate the index condition.
*/
if (padLen <= 0) {
return NULL;
}
errno_t rc = EOK;
int totalLen = curLen + padLen * buflen;
char *originstr = (char*)palloc(totalLen + 1);
rc = memcpy_s(originstr, totalLen, workstr, curLen);
securec_check(rc, "\0", "\0");
while ((curLen + buflen) <= totalLen) {
rc = memcpy_s(originstr + curLen, totalLen - curLen, buf, buflen);
securec_check(rc, "\0", "\0");
curLen += buflen;
}
originstr[curLen] = '\0';
Const *workstr_const = string_to_const(originstr, datatype);
pfree(workstr);
pfree(originstr);
return workstr_const;
}
* Given a fixed prefix that all the "leftop" values must have,
* generate suitable indexqual condition(s). opfamily is the index
* operator family; we use it to deduce the appropriate comparison
* operators and operand datatypes. collation is the input collation to use.
*/
static List* prefix_quals(Node* leftop, Oid opfamily, Oid collation, Const* prefix_const,
Pattern_Prefix_Status pstatus, int prefixkey_len)
{
List* result = NIL;
Oid datatype;
Oid oproid;
Expr* expr = NULL;
FmgrInfo ltproc;
Const* greaterstr = NULL;
AssertEreport(pstatus != Pattern_Prefix_None, MOD_OPT, "Pattern prefix is none");
switch (opfamily) {
case TEXT_BTREE_FAM_OID:
case TEXT_PATTERN_BTREE_FAM_OID:
case TEXT_SPGIST_FAM_OID:
case TEXT_UBTREE_FAM_OID:
case TEXT_PATTERN_UBTREE_FAM_OID:
datatype = TEXTOID;
break;
case BPCHAR_BTREE_FAM_OID:
case BPCHAR_PATTERN_BTREE_FAM_OID:
case BPCHAR_UBTREE_FAM_OID:
case BPCHAR_PATTERN_UBTREE_FAM_OID:
datatype = BPCHAROID;
break;
case NAME_BTREE_FAM_OID:
case NAME_UBTREE_FAM_OID:
datatype = NAMEOID;
break;
case BYTEA_BTREE_FAM_OID:
case BYTEA_UBTREE_FAM_OID:
datatype = BYTEAOID;
break;
default:
if (u_sess->attr.attr_sql.sql_compatibility == B_FORMAT) {
if (OpfamilynameGetOpfid(BTREE_AM_OID, "binary_ops") == opfamily) {
datatype = get_typeoid(PG_CATALOG_NAMESPACE, "binary");
break;
} else if (OpfamilynameGetOpfid(BTREE_AM_OID, "varbinary_ops") == opfamily) {
datatype = get_typeoid(PG_CATALOG_NAMESPACE, "varbinary");
break;
}
}
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg("unexpected opfamily when generate indexqual condition by prefix quals: %u", opfamily))));
return NIL;
}
* If necessary, coerce the prefix constant to the right type. The given
* prefix constant is either text or bytea type.
*/
if (prefix_const->consttype != datatype && (u_sess->attr.attr_sql.sql_compatibility != B_FORMAT
|| (datatype != get_typeoid(PG_CATALOG_NAMESPACE, "binary") &&
datatype != get_typeoid(PG_CATALOG_NAMESPACE, "varbinary")))) {
char* prefix = NULL;
switch (prefix_const->consttype) {
case TEXTOID:
prefix = TextDatumGetCString(prefix_const->constvalue);
break;
case BYTEAOID:
prefix = DatumGetCString(DirectFunctionCall1(byteaout, prefix_const->constvalue));
break;
default:
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_CASE_NOT_FOUND),
(errmsg("unexpected const type when generate indexqual condition by prefix quals: %u",
prefix_const->consttype))));
return NIL;
}
prefix_const = string_to_const(prefix, datatype);
pfree_ext(prefix);
}
* If matched key is prefix key, try generate an "=" indexqual firstly.
*/
if (prefixkey_len > 0) {
int prefix_const_len = (datatype == BYTEAOID) ?
(int)VARSIZE_ANY_EXHDR(DatumGetPointer(prefix_const->constvalue)) :
text_length(prefix_const->constvalue);
if (prefixkey_len <= prefix_const_len) {
prefix_const = prefix_const_node(prefix_const, prefixkey_len, datatype);
oproid = get_opfamily_member(opfamily, datatype, datatype, BTEqualStrategyNumber);
if (oproid == InvalidOid)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg("no = operator for opfamily %u when generate indexqual condition by prefix quals",
opfamily))));
expr = make_opclause(oproid, BOOLOID, false, (Expr*)leftop, (Expr*)prefix_const, InvalidOid, collation);
result = list_make1(make_simple_restrictinfo(expr));
return result;
}
}
* If we found an exact-match pattern, generate an "=" indexqual.
*/
if (pstatus == Pattern_Prefix_Exact) {
oproid = get_opfamily_member(opfamily, datatype, datatype, BTEqualStrategyNumber);
if (oproid == InvalidOid)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg(
"no = operator for opfamily %u when generate indexqual condition by prefix quals", opfamily))));
expr = make_opclause(oproid, BOOLOID, false, (Expr*)leftop, (Expr*)prefix_const, InvalidOid, collation);
result = list_make1(make_simple_restrictinfo(expr));
return result;
}
* In B format, we use a more universally applicable approach.
* We find the maximum and minimum characters sorted in the corresponding collation,
* and convert the index condition to x >= prefix\min\min... and x <= prefix\max\max.
* This approach eliminates the need to consider whether the character obtained from make_greater_string is larger,
* allowing us to use the index with confidence. Currently,
* this approach is only implemented for B format collations,
* but we will consider opening it up to all collations in the future.
*/
if (is_b_format_collation(collation)) {
int padLen = get_pad_length(leftop, prefixkey_len);
if (padLen > 0) {
PadContent content = get_pad_content(collation);
Const *minstr = NULL;
oproid = get_opfamily_member(opfamily, datatype, datatype, BTGreaterEqualStrategyNumber);
if (oproid == InvalidOid)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg(
"no >= operator for opfamily %u when generate indexqual condition by prefix quals",
opfamily))));
minstr = pad_string_in_like(content, prefix_const, padLen, false);
if (minstr != NULL) {
expr = make_opclause(oproid, BOOLOID, false, (Expr*)leftop, (Expr*)minstr, InvalidOid, collation);
result = lappend(result, make_simple_restrictinfo(expr));
}
oproid = get_opfamily_member(opfamily, datatype, datatype, BTLessEqualStrategyNumber);
if (oproid == InvalidOid)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg(
"no <= operator for opfamily %u when generate indexqual condition by prefix quals",
opfamily))));
greaterstr = pad_string_in_like(content, prefix_const, padLen, true);
if (greaterstr != NULL) {
expr = make_opclause(oproid, BOOLOID, false, (Expr*)leftop, (Expr*)greaterstr, InvalidOid, collation);
result = lappend(result, make_simple_restrictinfo(expr));
}
}
} else {
* Otherwise, we have a nonempty required prefix of the values.
*
* We can always say "x >= prefix".
*/
oproid = get_opfamily_member(opfamily, datatype, datatype, BTGreaterEqualStrategyNumber);
if (oproid == InvalidOid)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg(
"no >= operator for opfamily %u when generate indexqual condition by prefix quals",
opfamily))));
expr = make_opclause(oproid, BOOLOID, false, (Expr*)leftop, (Expr*)prefix_const, InvalidOid, collation);
result = list_make1(make_simple_restrictinfo(expr));
* If we can create a string larger than the prefix, we can say
* "x < greaterstr". NB: we rely on make_greater_string() to generate
* a guaranteed-greater string, not just a probably-greater string.
* In general this is only guaranteed in C locale, so we'd better be
* using a C-locale index collation.
* -------
*/
oproid = get_opfamily_member(opfamily, datatype, datatype, BTLessStrategyNumber);
if (oproid == InvalidOid)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg(
"no < operator for opfamily %u when generate indexqual condition by prefix quals",
opfamily))));
fmgr_info(get_opcode(oproid), <proc);
greaterstr = make_greater_string(prefix_const, <proc, collation);
if (greaterstr != NULL) {
expr = make_opclause(oproid, BOOLOID, false, (Expr*)leftop, (Expr*)greaterstr, InvalidOid, collation);
result = lappend(result, make_simple_restrictinfo(expr));
}
}
return result;
}
static List* prefix_quals_with_encdoing(Node* leftop, Oid opfamily, Oid collation, Const* prefix_const,
Pattern_Prefix_Status pstatus, int prefixkey_len)
{
List* result = NULL;
int tmp_encoding = get_valid_charset_by_collation(prefix_const->constcollid);
int db_encoding = GetDatabaseEncoding();
if (tmp_encoding == db_encoding) {
return prefix_quals(leftop, opfamily, collation, prefix_const, pstatus, prefixkey_len);
}
DB_ENCODING_SWITCH_TO(tmp_encoding);
result = prefix_quals(leftop, opfamily, collation, prefix_const, pstatus, prefixkey_len);
DB_ENCODING_SWITCH_BACK(db_encoding);
return result;
}
* Given a leftop and a rightop, and a inet-family sup/sub operator,
* generate suitable indexqual condition(s). expr_op is the original
* operator, and opfamily is the index opfamily.
*/
static List* network_prefix_quals(Node* leftop, Oid expr_op, Oid opfamily, Datum rightop)
{
bool is_eq = false;
Oid datatype;
Oid opr1oid;
Oid opr2oid;
Datum opr1right;
Datum opr2right;
List* result = NIL;
Expr* expr = NULL;
switch (expr_op) {
case OID_INET_SUB_OP:
datatype = INETOID;
is_eq = false;
break;
case OID_INET_SUBEQ_OP:
datatype = INETOID;
is_eq = true;
break;
default:
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_CASE_NOT_FOUND),
(errmsg("unexpected operator when generate indexqual condition by network prefix quals: %u",
expr_op))));
return NIL;
}
* create clause "key >= network_scan_first( rightop )", or ">" if the
* operator disallows equality.
*/
if (is_eq) {
opr1oid = get_opfamily_member(opfamily, datatype, datatype, BTGreaterEqualStrategyNumber);
if (opr1oid == InvalidOid)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg("no >= operator for opfamily %u when generate indexqual condition by network prefix quals",
opfamily))));
} else {
opr1oid = get_opfamily_member(opfamily, datatype, datatype, BTGreaterStrategyNumber);
if (opr1oid == InvalidOid)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg("no > operator for opfamily %u when generate indexqual condition by network prefix quals",
opfamily))));
}
opr1right = network_scan_first(rightop);
expr = make_opclause(opr1oid,
BOOLOID,
false,
(Expr*)leftop,
(Expr*)makeConst(datatype,
-1,
InvalidOid,
-1,
opr1right,
false,
false),
InvalidOid,
InvalidOid);
result = list_make1(make_simple_restrictinfo(expr));
opr2oid = get_opfamily_member(opfamily, datatype, datatype, BTLessEqualStrategyNumber);
if (opr2oid == InvalidOid)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg("no <= operator for opfamily %u when generate indexqual condition by network prefix quals",
opfamily))));
opr2right = network_scan_last(rightop);
expr = make_opclause(opr2oid,
BOOLOID,
false,
(Expr*)leftop,
(Expr*)makeConst(datatype,
-1,
InvalidOid,
-1,
opr2right,
false,
false),
InvalidOid,
InvalidOid);
result = lappend(result, make_simple_restrictinfo(expr));
return result;
}
* Handy subroutines for match_special_index_operator() and friends.
*/
* Generate a Datum of the appropriate type from a C string.
* Note that all of the supported types are pass-by-ref, so the
* returned value should be pfree'd if no longer needed.
*/
static Datum string_to_datum(const char* str, Oid datatype)
{
* We cheat a little by assuming that CStringGetTextDatum() will do for
* bpchar and varchar constants too...
*/
if (datatype == NAMEOID)
return DirectFunctionCall1(namein, CStringGetDatum(str));
else if (datatype == BYTEAOID)
return DirectFunctionCall1(byteain, CStringGetDatum(str));
else if (datatype == BYTEAWITHOUTORDERWITHEQUALCOLOID)
return DirectFunctionCall1(byteawithoutorderwithequalcolin, CStringGetDatum(str));
else if (datatype == BYTEAWITHOUTORDERCOLOID)
return DirectFunctionCall1(byteawithoutordercolin, CStringGetDatum(str));
else
return CStringGetTextDatum(str);
}
* Generate a Const node of the appropriate type from a C string.
*/
static Const* string_to_const(const char* str, Oid datatype)
{
Datum conval = string_to_datum(str, datatype);
Oid collation;
int constlen;
* We only need to support a few datatypes here, so hard-wire properties
* instead of incurring the expense of catalog lookups.
*/
switch (datatype) {
case TEXTOID:
case VARCHAROID:
case BPCHAROID:
collation = DEFAULT_COLLATION_OID;
constlen = -1;
break;
case NAMEOID:
collation = InvalidOid;
constlen = NAMEDATALEN;
break;
case BYTEAOID:
collation = InvalidOid;
constlen = -1;
break;
default:
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_CASE_NOT_FOUND),
(errmsg("unexpected datatype in string_to_const: %u", datatype))));
return NULL;
}
return makeConst(datatype, -1, collation, constlen, conval, false, false);
}
* get_index_column_prefix_lenth
* Get the prefix length of a specified index column.
* Returns length if it is a prefix key, otherwise returns 0.
*/
static int get_index_column_prefix_lenth(IndexOptInfo *index, int indexcol)
{
if (index->indexkeys[indexcol] != 0) {
return 0;
}
Node* indexkey = NULL;
ListCell* indexpr_item = list_head(index->indexprs);
if (indexpr_item == NULL) {
return 0;
}
for (int i = 0; i < indexcol; i++) {
if (index->indexkeys[i] != 0) {
continue;
}
indexpr_item = lnext(indexpr_item);
if (indexpr_item == NULL) {
return 0;
}
}
indexkey = (Node*)lfirst(indexpr_item);
if (indexkey && IsA(indexkey, RelabelType)) {
indexkey = (Node*)((RelabelType*)indexkey)->arg;
}
if (indexkey && IsA(indexkey, PrefixKey)) {
return ((PrefixKey*)indexkey)->length;
}
return 0;
}
static Const* prefix_const_node(Const* con, int prefix_len, Oid datatype)
{
int prefix_const_len;
Datum prefix_value;
if (datatype == BYTEAOID || datatype == RAWOID || datatype == BLOBOID) {
prefix_const_len = VARSIZE_ANY_EXHDR(DatumGetPointer(con->constvalue));
if (prefix_len < prefix_const_len) {
prefix_value = PointerGetDatum(bytea_substring(con->constvalue, 1, prefix_len, false));
return makeConst(datatype, -1, con->constcollid, con->constlen, prefix_value, false, false);
}
} else {
int charset = get_valid_charset_by_collation(con->constcollid);
prefix_const_len = text_length_with_encoding(con->constvalue, charset);
if (prefix_len < prefix_const_len) {
prefix_value = PointerGetDatum(text_substring_with_encoding(con->constvalue, 1, prefix_len, false, charset));
return makeConst(datatype, -1, con->constcollid, con->constlen, prefix_value, false, false);
}
}
return con;
}
* rewrite_opclause_for_prefixkey
* Rewrite an indexqual for prefix key.
*
* The prefix key stores only the prefix of a column. Index scan using the original
* indexqual may miss some keys we need. The indexqual for index scanning must
* include all possible keys.
*
* For example:
* If index prefix key length is 3, we cannot use clause (prefixkey > 'ABC123') to
* approach index key 'ABC'. However, the column value corresponding to this key value
* may meets the clause. We can find right keys in index scan by converting the
* clause to (prefixkey >= 'ABC').
*/
static RestrictInfo* rewrite_opclause_for_prefixkey(RestrictInfo *rinfo, IndexOptInfo* index, Oid opfamily,
int prefix_len)
{
OpExpr* op = (OpExpr*)rinfo->clause;
Oid oproid = op->opno;
Node *leftop = NULL;
Node *rightop = NULL;
Node *chgnode = NULL;
Expr* newop = NULL;
int strategy;
* An index with a prefix key must be a btree index.
* We only need to rewrite binary OpExpr.
*/
if (list_length(op->args) != 2) {
return rinfo;
}
leftop = (Node*)linitial(op->args);
rightop = (Node*)lsecond(op->args);
* Check where indexkey is, rewrite the expression on the other side.
*/
chgnode = (bms_equal(rinfo->left_relids, index->rel->relids)) ? rightop : leftop;
if (IsA(chgnode, Const)) {
* Prefixes the Const if its length is longger than prefix length.
*/
chgnode = (Node*)prefix_const_node((Const*)chgnode, prefix_len, ((Const*)chgnode)->consttype);
} else {
* Add PrefixeKey node on the expression.
*/
PrefixKey *pexpr = makeNode(PrefixKey);
pexpr->length = prefix_len;
pexpr->arg = (Expr*)chgnode;
chgnode = (Node*)pexpr;
}
if (bms_equal(rinfo->left_relids, index->rel->relids)) {
rightop = chgnode;
} else {
leftop = chgnode;
}
* Operators "> and "<" may cause required keys to be skipped.
* Replace them with ">=" or "<=".
*/
strategy = get_op_opfamily_strategy(oproid, opfamily);
if (strategy == BTGreaterStrategyNumber) {
oproid = get_opfamily_member(opfamily, exprType(leftop), exprType(rightop), BTGreaterEqualStrategyNumber);
} else if (strategy == BTLessStrategyNumber) {
oproid = get_opfamily_member(opfamily, exprType(leftop), exprType(rightop), BTLessEqualStrategyNumber);
}
if (oproid == InvalidOid)
ereport(ERROR,
(errmodule(MOD_OPT),
errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
(errmsg(
"no >= or <= operator for opfamily %u when generate indexqual for prefix key", opfamily))));
newop = make_opclause(oproid, BOOLOID, op->opretset, (Expr*)leftop, (Expr*)rightop, op->opcollid, op->inputcollid);
return make_simple_restrictinfo(newop);
}
* Check whether there are risks caused by type conversion.
* If yes, report cause_type.
*/
void check_report_cause_type(FuncExpr* funcExpr, int indkey)
{
Node* varNode = NULL;
ListCell* argsCell = NULL;
if (list_length(funcExpr->args) != 1) {
return;
}
argsCell = list_head(funcExpr->args);
Node* node = (Node*)lfirst(argsCell);
if (IsA(node, Var)) {
varNode = node;
} else if (IsA(node, FuncExpr)) {
varNode = match_first_var_to_indkey(node, indkey);
}
if (IsFunctionTransferNumDistinct(funcExpr) && varNode != NULL && IsA(varNode, Var) &&
indkey == ((Var*)varNode)->varattno) {
instr_stmt_report_cause_type(NUM_F_TYPECASTING);
}
}
* return the first var that matches the index column
* return NULL if not exist
*/
Node* match_first_var_to_indkey(Node* node, int indkey)
{
Node* lastNode = NULL;
List* varList = pull_var_clause(node, PVC_RECURSE_AGGREGATES, PVC_RECURSE_PLACEHOLDERS, PVC_RECURSE_SPECIAL_EXPR);
if (varList != NULL) {
ListCell* var_cell = NULL;
foreach (var_cell, varList) {
Node* var = (Node*)lfirst(var_cell);
if (indkey == ((Var*)var)->varattno) {
lastNode = var;
break;
}
}
}
return lastNode;
}
static Node *strip_array_coercion(Node *node)
{
while (node) {
if (IsA(node, ArrayCoerceExpr) && ((ArrayCoerceExpr*)node)->elemfuncid == InvalidOid) {
node = (Node*)((ArrayCoerceExpr*)node)->arg;
} else if (IsA(node, RelabelType)) {
node = (Node*)((RelabelType*)node)->arg;
} else {
break;
}
}
return node;
}
static bool scalar_array_can_match_prefixkey(Node *saop_rexpr)
{
Node* rexpr = strip_array_coercion(saop_rexpr);
if (!rexpr) {
return false;
}
if (IsA(rexpr, Const) ||
(IsA(rexpr, ArrayExpr) && !((ArrayExpr*)rexpr)->multidims)) {
return true;
}
return false;
}
Datum get_prefix_datum(Datum src, int prefix_len, Oid datatype)
{
int datum_len;
if (datatype == BYTEAOID || datatype == RAWOID || datatype == BLOBOID) {
datum_len = VARSIZE_ANY_EXHDR(DatumGetPointer(src));
if (prefix_len < datum_len) {
return PointerGetDatum(bytea_substring(src, 1, prefix_len, false));
}
} else {
datum_len = text_length(src);
if (prefix_len < datum_len) {
return PointerGetDatum(text_substring(src, 1, prefix_len, false));
}
}
return src;
}
void prefix_array_const_items(Const* arr_const, int prefixkey_len)
{
ArrayBuildState* astate = NULL;
Datum arraydatum = arr_const->constvalue;
ArrayType* arrayval = DatumGetArrayTypeP(arraydatum);
Oid elem_type = ARR_ELEMTYPE(arrayval);
int16 typlen;
bool typbyval;
char typalign;
Datum* elem_values = NULL;
bool* elem_nulls = NULL;
int num_elems;
get_typlenbyvalalign(elem_type, &typlen, &typbyval, &typalign);
deconstruct_array(arrayval, elem_type, typlen, typbyval, typalign, &elem_values, &elem_nulls, &num_elems);
Datum new_item;
for (int i = 0; i < num_elems; i++) {
if (elem_nulls[i]) {
new_item = 0;
} else {
new_item = get_prefix_datum(elem_values[i], prefixkey_len, elem_type);
}
astate = accumArrayResult(astate, PointerGetDatum(new_item), elem_nulls[i], elem_type, CurrentMemoryContext);
}
arr_const->constvalue = makeArrayResult(astate, CurrentMemoryContext);
pfree_ext(elem_nulls);
pfree_ext(elem_values);
}
void prefix_array_expr_items(ArrayExpr* arr_expr, int prefixkey_len)
{
Node* chgnode = NULL;
foreach_cell(lc, arr_expr->elements) {
chgnode = (Node*)lfirst(lc);
if (IsA(chgnode, Const)) {
chgnode = (Node*)prefix_const_node((Const*)chgnode, prefixkey_len, ((Const*)chgnode)->consttype);
} else {
PrefixKey* pexpr = makeNode(PrefixKey);
pexpr->length = prefixkey_len;
pexpr->arg = (Expr*)chgnode;
chgnode = (Node*)pexpr;
}
lfirst(lc) = chgnode;
}
}
static Oid replace_operator_by_strategy(Oid op_oid, Oid opfamily, int16 strategy)
{
Oid ltype;
Oid rtype;
get_operator_types(op_oid, <ype, &rtype);
return get_opfamily_member(opfamily, ltype, rtype, strategy);
}
RestrictInfo* expand_indexqual_scalar_array_op_expr(IndexOptInfo* index, RestrictInfo* rinfo,
Oid opfamily, int indexcol)
{
int prefixkey_len = get_index_column_prefix_lenth(index, indexcol);
if (prefixkey_len == 0) {
return rinfo;
}
RestrictInfo* new_rinfo = (RestrictInfo*)copyObject((Node*)rinfo);
ScalarArrayOpExpr* saop = (ScalarArrayOpExpr*)new_rinfo->clause;
Oid op_oid = saop->opno;
Node* rexpr = (Node*)lsecond(saop->args);
rexpr = strip_array_coercion(rexpr);
if (rexpr && IsA(rexpr, Const)) {
prefix_array_const_items((Const*)rexpr, prefixkey_len);
} else if (rexpr && IsA(rexpr, ArrayExpr) && !((ArrayExpr*)rexpr)->multidims) {
prefix_array_expr_items((ArrayExpr*)rexpr, prefixkey_len);
} else {
ereport(ERROR, (errcode(ERRCODE_UNRECOGNIZED_NODE_TYPE),
errmsg("unsupported indexqual type when expand indexqual conditions: %d", (int)nodeTag(saop)),
errdetail("Cannot rewrite expression %d for prefix key index.", rexpr ? (int)nodeTag(rexpr) : 0)));
}
* Operators "> and "<" may cause required keys to be skipped.
* Replace them with ">=" or "<=".
*/
int strategy = get_op_opfamily_strategy(op_oid, opfamily);
if (strategy == BTGreaterStrategyNumber) {
saop->opno = replace_operator_by_strategy(op_oid, opfamily, BTGreaterStrategyNumber);
} else if (strategy == BTLessStrategyNumber) {
saop->opno = replace_operator_by_strategy(op_oid, opfamily, BTLessStrategyNumber);
}
if (saop->opno == InvalidOid) {
ereport(ERROR, (errcode(ERRCODE_OPTIMIZER_INCONSISTENT_STATE),
errmsg("no >= or <= operator for opfamily %u when generate indexqual for prefix key", opfamily)));
}
saop->opfuncid = get_opcode(saop->opno);
return new_rinfo;
}
