diff options
Diffstat (limited to 'src/backend/optimizer/path/pathkeys.c')
| -rw-r--r-- | src/backend/optimizer/path/pathkeys.c | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/src/backend/optimizer/path/pathkeys.c b/src/backend/optimizer/path/pathkeys.c index 012cb62f89a..1065b31ad10 100644 --- a/src/backend/optimizer/path/pathkeys.c +++ b/src/backend/optimizer/path/pathkeys.c @@ -480,17 +480,30 @@ build_index_pathkeys(PlannerInfo *root, index->rel->relids, false); - /* - * If the sort key isn't already present in any EquivalenceClass, then - * it's not an interesting sort order for this query. So we can stop - * now --- lower-order sort keys aren't useful either. - */ - if (!cpathkey) - break; - - /* Add to list unless redundant */ - if (!pathkey_is_redundant(cpathkey, retval)) - retval = lappend(retval, cpathkey); + if (cpathkey) + { + /* + * We found the sort key in an EquivalenceClass, so it's relevant + * for this query. Add it to list, unless it's redundant. + */ + if (!pathkey_is_redundant(cpathkey, retval)) + retval = lappend(retval, cpathkey); + } + else + { + /* + * Boolean index keys might be redundant even if they do not + * appear in an EquivalenceClass, because of our special treatment + * of boolean equality conditions --- see the comment for + * indexcol_is_bool_constant_for_query(). If that applies, we can + * continue to examine lower-order index columns. Otherwise, the + * sort key is not an interesting sort order for this query, so we + * should stop considering index columns; any lower-order sort + * keys won't be useful either. + */ + if (!indexcol_is_bool_constant_for_query(index, i)) + break; + } i++; } |