diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/optimizer/path/equivclass.c | 37 |
1 files changed, 32 insertions, 5 deletions
diff --git a/src/backend/optimizer/path/equivclass.c b/src/backend/optimizer/path/equivclass.c index 5d92c7c8df2..bf93fc2e667 100644 --- a/src/backend/optimizer/path/equivclass.c +++ b/src/backend/optimizer/path/equivclass.c @@ -10,7 +10,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/path/equivclass.c,v 1.6 2007/11/15 22:25:15 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/path/equivclass.c,v 1.7 2007/11/23 19:57:44 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -559,6 +559,25 @@ generate_base_implied_equalities_const(PlannerInfo *root, EquivalenceMember *const_em = NULL; ListCell *lc; + /* + * In the trivial case where we just had one "var = const" clause, + * push the original clause back into the main planner machinery. There + * is nothing to be gained by doing it differently, and we save the + * effort to re-build and re-analyze an equality clause that will be + * exactly equivalent to the old one. + */ + if (list_length(ec->ec_members) == 2 && + list_length(ec->ec_sources) == 1) + { + RestrictInfo *restrictinfo = (RestrictInfo *) linitial(ec->ec_sources); + + if (bms_membership(restrictinfo->required_relids) != BMS_MULTIPLE) + { + distribute_restrictinfo_to_rels(root, restrictinfo); + return; + } + } + /* Find the constant member to use */ foreach(lc, ec->ec_members) { @@ -1047,7 +1066,8 @@ create_join_clause(PlannerInfo *root, rinfo = build_implied_join_equality(opno, leftem->em_expr, rightem->em_expr, - ec->ec_relids); + bms_union(leftem->em_relids, + rightem->em_relids)); /* Mark the clause as redundant, or not */ rinfo->parent_ec = parent_ec; @@ -1165,6 +1185,7 @@ reconsider_outer_join_clause(PlannerInfo *root, RestrictInfo *rinfo, Oid left_type, right_type, inner_datatype; + Relids inner_relids; ListCell *lc1; /* Extract needed info from the clause */ @@ -1176,12 +1197,14 @@ reconsider_outer_join_clause(PlannerInfo *root, RestrictInfo *rinfo, outervar = (Expr *) get_leftop(rinfo->clause); innervar = (Expr *) get_rightop(rinfo->clause); inner_datatype = right_type; + inner_relids = rinfo->right_relids; } else { outervar = (Expr *) get_rightop(rinfo->clause); innervar = (Expr *) get_leftop(rinfo->clause); inner_datatype = left_type; + inner_relids = rinfo->left_relids; } /* Scan EquivalenceClasses for a match to outervar */ @@ -1237,7 +1260,7 @@ reconsider_outer_join_clause(PlannerInfo *root, RestrictInfo *rinfo, newrinfo = build_implied_join_equality(eq_op, innervar, cur_em->em_expr, - cur_ec->ec_relids); + inner_relids); if (process_equivalence(root, newrinfo, true)) match = true; } @@ -1268,6 +1291,8 @@ reconsider_full_join_clause(PlannerInfo *root, RestrictInfo *rinfo) Expr *rightvar; Oid left_type, right_type; + Relids left_relids, + right_relids; ListCell *lc1; /* Extract needed info from the clause */ @@ -1276,6 +1301,8 @@ reconsider_full_join_clause(PlannerInfo *root, RestrictInfo *rinfo) rightvar = (Expr *) get_rightop(rinfo->clause); op_input_types(((OpExpr *) rinfo->clause)->opno, &left_type, &right_type); + left_relids = rinfo->left_relids; + right_relids = rinfo->right_relids; foreach(lc1, root->eq_classes) { @@ -1357,7 +1384,7 @@ reconsider_full_join_clause(PlannerInfo *root, RestrictInfo *rinfo) newrinfo = build_implied_join_equality(eq_op, leftvar, cur_em->em_expr, - cur_ec->ec_relids); + left_relids); if (process_equivalence(root, newrinfo, true)) matchleft = true; } @@ -1369,7 +1396,7 @@ reconsider_full_join_clause(PlannerInfo *root, RestrictInfo *rinfo) newrinfo = build_implied_join_equality(eq_op, rightvar, cur_em->em_expr, - cur_ec->ec_relids); + right_relids); if (process_equivalence(root, newrinfo, true)) matchright = true; } |