diff options
Diffstat (limited to 'src/backend/optimizer/path/pathkeys.c')
| -rw-r--r-- | src/backend/optimizer/path/pathkeys.c | 41 |
1 files changed, 16 insertions, 25 deletions
diff --git a/src/backend/optimizer/path/pathkeys.c b/src/backend/optimizer/path/pathkeys.c index 2994421e5b7..52075fbf465 100644 --- a/src/backend/optimizer/path/pathkeys.c +++ b/src/backend/optimizer/path/pathkeys.c @@ -11,7 +11,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/path/pathkeys.c,v 1.67 2005/06/05 22:32:55 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/path/pathkeys.c,v 1.68 2005/06/09 04:18:59 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1157,11 +1157,11 @@ make_pathkeys_for_mergeclauses(PlannerInfo *root, /* * pathkeys_useful_for_merging * Count the number of pathkeys that may be useful for mergejoins - * above the given relation (by looking at its joininfo lists). + * above the given relation (by looking at its joininfo list). * * We consider a pathkey potentially useful if it corresponds to the merge * ordering of either side of any joinclause for the rel. This might be - * overoptimistic, since joinclauses that appear in different join lists + * overoptimistic, since joinclauses that require different other relations * might never be usable at the same time, but trying to be exact is likely * to be more trouble than it's worth. */ @@ -1179,31 +1179,22 @@ pathkeys_useful_for_merging(PlannerInfo *root, RelOptInfo *rel, List *pathkeys) foreach(j, rel->joininfo) { - JoinInfo *joininfo = (JoinInfo *) lfirst(j); - ListCell *k; - - foreach(k, joininfo->jinfo_restrictinfo) - { - RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(k); - - if (restrictinfo->mergejoinoperator == InvalidOid) - continue; - cache_mergeclause_pathkeys(root, restrictinfo); + RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(j); - /* - * We can compare canonical pathkey sublists by simple - * pointer equality; see compare_pathkeys. - */ - if (pathkey == restrictinfo->left_pathkey || - pathkey == restrictinfo->right_pathkey) - { - matched = true; - break; - } - } + if (restrictinfo->mergejoinoperator == InvalidOid) + continue; + cache_mergeclause_pathkeys(root, restrictinfo); - if (matched) + /* + * We can compare canonical pathkey sublists by simple + * pointer equality; see compare_pathkeys. + */ + if (pathkey == restrictinfo->left_pathkey || + pathkey == restrictinfo->right_pathkey) + { + matched = true; break; + } } /* |