diff options
Diffstat (limited to 'src/backend/optimizer/path/clausesel.c')
| -rw-r--r-- | src/backend/optimizer/path/clausesel.c | 69 |
1 files changed, 52 insertions, 17 deletions
diff --git a/src/backend/optimizer/path/clausesel.c b/src/backend/optimizer/path/clausesel.c index 1ba578130e9..614c1d127ca 100644 --- a/src/backend/optimizer/path/clausesel.c +++ b/src/backend/optimizer/path/clausesel.c @@ -41,7 +41,8 @@ typedef struct RangeQueryClause static void addRangeClause(RangeQueryClause **rqlist, Node *clause, bool varonleft, bool isLTsel, Selectivity s2); - +static RelOptInfo *find_relation_from_clauses(PlannerInfo *root, + List *clauses); /**************************************************************************** * ROUTINES TO COMPUTE SELECTIVITIES @@ -101,14 +102,14 @@ clauselist_selectivity(PlannerInfo *root, List *clauses, int varRelid, JoinType jointype, - SpecialJoinInfo *sjinfo, - RelOptInfo *rel) + SpecialJoinInfo *sjinfo) { Selectivity s1 = 1.0; RangeQueryClause *rqlist = NULL; ListCell *l; Bitmapset *estimatedclauses = NULL; int listidx; + RelOptInfo *rel; /* * If there's exactly one clause, then extended statistics is futile at @@ -117,7 +118,14 @@ clauselist_selectivity(PlannerInfo *root, */ if (list_length(clauses) == 1) return clause_selectivity(root, (Node *) linitial(clauses), - varRelid, jointype, sjinfo, rel); + varRelid, jointype, sjinfo); + + /* + * Determine if these clauses reference a single relation. If so we might + * like to try applying any extended statistics which exist on it. + * Called many time during joins, so must return NULL quickly if not. + */ + rel = find_relation_from_clauses(root, clauses); /* * When a relation of RTE_RELATION is given as 'rel', we'll try to @@ -164,7 +172,7 @@ clauselist_selectivity(PlannerInfo *root, continue; /* Always compute the selectivity using clause_selectivity */ - s2 = clause_selectivity(root, clause, varRelid, jointype, sjinfo, rel); + s2 = clause_selectivity(root, clause, varRelid, jointype, sjinfo); /* * Check for being passed a RestrictInfo. @@ -418,6 +426,39 @@ addRangeClause(RangeQueryClause **rqlist, Node *clause, } /* + * find_relation_from_clauses + * Process each clause in 'clauses' and determine if all clauses + * reference only a single relation. If so return that relation, + * otherwise return NULL. + */ +static RelOptInfo * +find_relation_from_clauses(PlannerInfo *root, List *clauses) +{ + ListCell *l; + int relid; + int lastrelid = 0; + + foreach(l, clauses) + { + RestrictInfo *rinfo = (RestrictInfo *) lfirst(l); + + if (bms_get_singleton_member(rinfo->clause_relids, &relid)) + { + if (lastrelid != 0 && relid != lastrelid) + return NULL; /* relation not the same as last one */ + lastrelid = relid; + } + else + return NULL; /* multiple relations in clause */ + } + + if (lastrelid != 0) + return find_base_rel(root, lastrelid); + + return NULL; /* no clauses */ +} + +/* * bms_is_subset_singleton * * Same result as bms_is_subset(s, bms_make_singleton(x)), @@ -529,8 +570,7 @@ clause_selectivity(PlannerInfo *root, Node *clause, int varRelid, JoinType jointype, - SpecialJoinInfo *sjinfo, - RelOptInfo *rel) + SpecialJoinInfo *sjinfo) { Selectivity s1 = 0.5; /* default for any unhandled clause type */ RestrictInfo *rinfo = NULL; @@ -650,8 +690,7 @@ clause_selectivity(PlannerInfo *root, (Node *) get_notclausearg((Expr *) clause), varRelid, jointype, - sjinfo, - rel); + sjinfo); } else if (and_clause(clause)) { @@ -660,8 +699,7 @@ clause_selectivity(PlannerInfo *root, ((BoolExpr *) clause)->args, varRelid, jointype, - sjinfo, - rel); + sjinfo); } else if (or_clause(clause)) { @@ -680,8 +718,7 @@ clause_selectivity(PlannerInfo *root, (Node *) lfirst(arg), varRelid, jointype, - sjinfo, - rel); + sjinfo); s1 = s1 + s2 - s1 * s2; } @@ -774,8 +811,7 @@ clause_selectivity(PlannerInfo *root, (Node *) ((RelabelType *) clause)->arg, varRelid, jointype, - sjinfo, - rel); + sjinfo); } else if (IsA(clause, CoerceToDomain)) { @@ -784,8 +820,7 @@ clause_selectivity(PlannerInfo *root, (Node *) ((CoerceToDomain *) clause)->arg, varRelid, jointype, - sjinfo, - rel); + sjinfo); } else { |