diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/optimizer/path/indxpath.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c index 7fc70804f8b..594ac8eacbe 100644 --- a/src/backend/optimizer/path/indxpath.c +++ b/src/backend/optimizer/path/indxpath.c @@ -1866,6 +1866,7 @@ check_index_only(RelOptInfo *rel, IndexOptInfo *index) bool result; Bitmapset *attrs_used = NULL; Bitmapset *index_canreturn_attrs = NULL; + Bitmapset *index_cannotreturn_attrs = NULL; ListCell *lc; int i; @@ -1905,7 +1906,11 @@ check_index_only(RelOptInfo *rel, IndexOptInfo *index) /* * Construct a bitmapset of columns that the index can return back in an - * index-only scan. + * index-only scan. If there are multiple index columns containing the + * same attribute, all of them must be capable of returning the value, + * since we might recheck operators on any of them. (Potentially we could + * be smarter about that, but it's such a weird situation that it doesn't + * seem worth spending a lot of sweat on.) */ for (i = 0; i < index->ncolumns; i++) { @@ -1922,13 +1927,21 @@ check_index_only(RelOptInfo *rel, IndexOptInfo *index) index_canreturn_attrs = bms_add_member(index_canreturn_attrs, attno - FirstLowInvalidHeapAttributeNumber); + else + index_cannotreturn_attrs = + bms_add_member(index_cannotreturn_attrs, + attno - FirstLowInvalidHeapAttributeNumber); } + index_canreturn_attrs = bms_del_members(index_canreturn_attrs, + index_cannotreturn_attrs); + /* Do we have all the necessary attributes? */ result = bms_is_subset(attrs_used, index_canreturn_attrs); bms_free(attrs_used); bms_free(index_canreturn_attrs); + bms_free(index_cannotreturn_attrs); return result; } |