diff options
Diffstat (limited to 'src/backend/optimizer/path/equivclass.c')
| -rw-r--r-- | src/backend/optimizer/path/equivclass.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/src/backend/optimizer/path/equivclass.c b/src/backend/optimizer/path/equivclass.c index fc862438ffb..18c6ff93686 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 1.3 2007/07/07 20:46:45 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/path/equivclass.c,v 1.4 2007/11/08 21:49:47 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -294,6 +294,7 @@ process_equivalence(PlannerInfo *root, RestrictInfo *restrictinfo, ec->ec_has_volatile = false; ec->ec_below_outer_join = below_outer_join; ec->ec_broken = false; + ec->ec_sortref = 0; ec->ec_merged = NULL; em1 = add_eq_member(ec, item1, item1_relids, false, item1_type); em2 = add_eq_member(ec, item2, item2_relids, false, item2_type); @@ -354,6 +355,9 @@ add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids, * class it is a member of; if none, build a new single-member * EquivalenceClass for it. * + * sortref is the SortGroupRef of the originating SortClause, if any, + * or zero if not. + * * This can be used safely both before and after EquivalenceClass merging; * since it never causes merging it does not invalidate any existing ECs * or PathKeys. @@ -367,7 +371,8 @@ EquivalenceClass * get_eclass_for_sort_expr(PlannerInfo *root, Expr *expr, Oid expr_datatype, - List *opfamilies) + List *opfamilies, + Index sortref) { EquivalenceClass *newec; EquivalenceMember *newem; @@ -382,7 +387,9 @@ get_eclass_for_sort_expr(PlannerInfo *root, EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1); ListCell *lc2; - /* we allow matching to a volatile EC here */ + /* Never match to a volatile EC */ + if (cur_ec->ec_has_volatile) + continue; if (!equal(opfamilies, cur_ec->ec_opfamilies)) continue; @@ -423,6 +430,7 @@ get_eclass_for_sort_expr(PlannerInfo *root, newec->ec_has_volatile = contain_volatile_functions((Node *) expr); newec->ec_below_outer_join = false; newec->ec_broken = false; + newec->ec_sortref = sortref; newec->ec_merged = NULL; newem = add_eq_member(newec, expr, pull_varnos((Node *) expr), false, expr_datatype); |