diff options
Diffstat (limited to 'src/backend/optimizer/path/orindxpath.c')
| -rw-r--r-- | src/backend/optimizer/path/orindxpath.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/src/backend/optimizer/path/orindxpath.c b/src/backend/optimizer/path/orindxpath.c index 1556bf74df6..c13a48d46b6 100644 --- a/src/backend/optimizer/path/orindxpath.c +++ b/src/backend/optimizer/path/orindxpath.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/path/orindxpath.c,v 1.84 2008/01/09 20:42:27 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/path/orindxpath.c,v 1.84.2.1 2009/04/16 20:42:28 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -89,12 +89,18 @@ create_or_index_quals(PlannerInfo *root, RelOptInfo *rel) ListCell *i; /* - * Find potentially interesting OR joinclauses. Note we must ignore any - * joinclauses that are marked outerjoin_delayed or !is_pushed_down, - * because they cannot be pushed down to the per-relation level due to - * outer-join rules. (XXX in some cases it might be possible to allow - * this, but it would require substantially more bookkeeping about where - * the clause came from.) + * Find potentially interesting OR joinclauses. + * + * We must ignore clauses for which the target rel is in nullable_relids; + * that means there's an outer join below the clause and so it can't be + * enforced at the relation scan level. + * + * We must also ignore clauses that are marked !is_pushed_down (ie they + * are themselves outer-join clauses). It would be safe to extract an + * index condition from such a clause if we are within the nullable rather + * than the non-nullable side of its join, but we haven't got enough + * context here to tell which applies. OR clauses in outer-join quals + * aren't exactly common, so we'll let that case go unoptimized for now. */ foreach(i, rel->joininfo) { @@ -102,7 +108,7 @@ create_or_index_quals(PlannerInfo *root, RelOptInfo *rel) if (restriction_is_or_clause(rinfo) && rinfo->is_pushed_down && - !rinfo->outerjoin_delayed) + !bms_is_member(rel->relid, rinfo->nullable_relids)) { /* * Use the generate_bitmap_or_paths() machinery to estimate the |