diff options
Diffstat (limited to 'src/backend/optimizer/path/clausesel.c')
| -rw-r--r-- | src/backend/optimizer/path/clausesel.c | 105 |
1 files changed, 50 insertions, 55 deletions
diff --git a/src/backend/optimizer/path/clausesel.c b/src/backend/optimizer/path/clausesel.c index e788f27873..6db42c5f58 100644 --- a/src/backend/optimizer/path/clausesel.c +++ b/src/backend/optimizer/path/clausesel.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/path/clausesel.c,v 1.91 2008/08/14 18:47:59 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/path/clausesel.c,v 1.92 2008/08/16 00:01:36 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -398,6 +398,50 @@ bms_is_subset_singleton(const Bitmapset *s, int x) return false; } +/* + * treat_as_join_clause - + * Decide whether an operator clause is to be handled by the + * restriction or join estimator. Subroutine for clause_selectivity(). + */ +static inline bool +treat_as_join_clause(Node *clause, RestrictInfo *rinfo, + int varRelid, SpecialJoinInfo *sjinfo) +{ + if (varRelid != 0) + { + /* + * Caller is forcing restriction mode (eg, because we are examining + * an inner indexscan qual). + */ + return false; + } + else if (sjinfo == NULL) + { + /* + * It must be a restriction clause, since it's being evaluated at + * a scan node. + */ + return false; + } + else + { + /* + * Otherwise, it's a join if there's more than one relation used. + * We can optimize this calculation if an rinfo was passed. + * + * XXX Since we know the clause is being evaluated at a join, + * the only way it could be single-relation is if it was delayed + * by outer joins. Although we can make use of the restriction + * qual estimators anyway, it seems likely that we ought to account + * for the probability of injected nulls somehow. + */ + if (rinfo) + return (bms_membership(rinfo->clause_relids) == BMS_MULTIPLE); + else + return (NumRelids(clause) > 1); + } +} + /* * clause_selectivity - @@ -429,9 +473,6 @@ bms_is_subset_singleton(const Bitmapset *s, int x) * root->join_info_list. * 2. For an INNER join, sjinfo is just a transient struct, and only the * relids and jointype fields in it can be trusted. - * 3. XXX sjinfo might be NULL even though it really is a join. This case - * will go away soon, but fixing it requires API changes for oprjoin and - * amcostestimate functions. * It is possible for jointype to be different from sjinfo->jointype. * This indicates we are considering a variant join: either with * the LHS and RHS switched, or with one input unique-ified. @@ -603,36 +644,14 @@ clause_selectivity(PlannerInfo *root, else if (is_opclause(clause) || IsA(clause, DistinctExpr)) { Oid opno = ((OpExpr *) clause)->opno; - bool is_join_clause; - if (varRelid != 0) - { - /* - * If we are considering a nestloop join then all clauses are - * restriction clauses, since we are only interested in the one - * relation. - */ - is_join_clause = false; - } - else - { - /* - * Otherwise, it's a join if there's more than one relation used. - * We can optimize this calculation if an rinfo was passed. - */ - if (rinfo) - is_join_clause = (bms_membership(rinfo->clause_relids) == - BMS_MULTIPLE); - else - is_join_clause = (NumRelids(clause) > 1); - } - - if (is_join_clause) + if (treat_as_join_clause(clause, rinfo, varRelid, sjinfo)) { /* Estimate selectivity for a join clause. */ s1 = join_selectivity(root, opno, ((OpExpr *) clause)->args, - jointype); + jointype, + sjinfo); } else { @@ -671,35 +690,11 @@ clause_selectivity(PlannerInfo *root, #endif else if (IsA(clause, ScalarArrayOpExpr)) { - /* First, decide if it's a join clause, same as for OpExpr */ - bool is_join_clause; - - if (varRelid != 0) - { - /* - * If we are considering a nestloop join then all clauses are - * restriction clauses, since we are only interested in the one - * relation. - */ - is_join_clause = false; - } - else - { - /* - * Otherwise, it's a join if there's more than one relation used. - * We can optimize this calculation if an rinfo was passed. - */ - if (rinfo) - is_join_clause = (bms_membership(rinfo->clause_relids) == - BMS_MULTIPLE); - else - is_join_clause = (NumRelids(clause) > 1); - } - /* Use node specific selectivity calculation function */ s1 = scalararraysel(root, (ScalarArrayOpExpr *) clause, - is_join_clause, + treat_as_join_clause(clause, rinfo, + varRelid, sjinfo), varRelid, jointype, sjinfo); |