diff options
Diffstat (limited to 'src/backend/optimizer/util')
| -rw-r--r-- | src/backend/optimizer/util/joininfo.c | 36 |
1 files changed, 35 insertions, 1 deletions
diff --git a/src/backend/optimizer/util/joininfo.c b/src/backend/optimizer/util/joininfo.c index b03045d657d..af1eccecb5d 100644 --- a/src/backend/optimizer/util/joininfo.c +++ b/src/backend/optimizer/util/joininfo.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/util/joininfo.c,v 1.52 2010/01/02 16:57:48 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/util/joininfo.c,v 1.52.6.1 2010/09/14 23:15:36 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -98,3 +98,37 @@ add_join_clause_to_rels(PlannerInfo *root, } bms_free(tmprelids); } + +/* + * remove_join_clause_from_rels + * Delete 'restrictinfo' from all the joininfo lists it is in + * + * This reverses the effect of add_join_clause_to_rels. It's used when we + * discover that a relation need not be joined at all. + * + * 'restrictinfo' describes the join clause + * 'join_relids' is the list of relations participating in the join clause + * (there must be more than one) + */ +void +remove_join_clause_from_rels(PlannerInfo *root, + RestrictInfo *restrictinfo, + Relids join_relids) +{ + Relids tmprelids; + int cur_relid; + + tmprelids = bms_copy(join_relids); + while ((cur_relid = bms_first_member(tmprelids)) >= 0) + { + RelOptInfo *rel = find_base_rel(root, cur_relid); + + /* + * Remove the restrictinfo from the list. Pointer comparison is + * sufficient. + */ + Assert(list_member_ptr(rel->joininfo, restrictinfo)); + rel->joininfo = list_delete_ptr(rel->joininfo, restrictinfo); + } + bms_free(tmprelids); +} |