diff options
Diffstat (limited to 'src/backend/optimizer/path/indxpath.c')
| -rw-r--r-- | src/backend/optimizer/path/indxpath.c | 90 |
1 files changed, 18 insertions, 72 deletions
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c index 32c6a8bbdcb..2230b131047 100644 --- a/src/backend/optimizer/path/indxpath.c +++ b/src/backend/optimizer/path/indxpath.c @@ -106,8 +106,7 @@ static List *build_index_paths(PlannerInfo *root, RelOptInfo *rel, IndexOptInfo *index, IndexClauseSet *clauses, bool useful_predicate, ScanTypeControl scantype, - bool *skip_nonnative_saop, - bool *skip_lower_saop); + bool *skip_nonnative_saop); static List *build_paths_for_OR(PlannerInfo *root, RelOptInfo *rel, List *clauses, List *other_clauses); static List *generate_bitmap_or_paths(PlannerInfo *root, RelOptInfo *rel, @@ -706,8 +705,6 @@ eclass_already_used(EquivalenceClass *parent_ec, Relids oldrelids, * index AM supports them natively, we should just include them in simple * index paths. If not, we should exclude them while building simple index * paths, and then make a separate attempt to include them in bitmap paths. - * Furthermore, we should consider excluding lower-order ScalarArrayOpExpr - * quals so as to create ordered paths. */ static void get_index_paths(PlannerInfo *root, RelOptInfo *rel, @@ -716,37 +713,17 @@ get_index_paths(PlannerInfo *root, RelOptInfo *rel, { List *indexpaths; bool skip_nonnative_saop = false; - bool skip_lower_saop = false; ListCell *lc; /* * Build simple index paths using the clauses. Allow ScalarArrayOpExpr - * clauses only if the index AM supports them natively, and skip any such - * clauses for index columns after the first (so that we produce ordered - * paths if possible). + * clauses only if the index AM supports them natively. */ indexpaths = build_index_paths(root, rel, index, clauses, index->predOK, ST_ANYSCAN, - &skip_nonnative_saop, - &skip_lower_saop); - - /* - * If we skipped any lower-order ScalarArrayOpExprs on an index with an AM - * that supports them, then try again including those clauses. This will - * produce paths with more selectivity but no ordering. - */ - if (skip_lower_saop) - { - indexpaths = list_concat(indexpaths, - build_index_paths(root, rel, - index, clauses, - index->predOK, - ST_ANYSCAN, - &skip_nonnative_saop, - NULL)); - } + &skip_nonnative_saop); /* * Submit all the ones that can form plain IndexScan plans to add_path. (A @@ -784,7 +761,6 @@ get_index_paths(PlannerInfo *root, RelOptInfo *rel, index, clauses, false, ST_BITMAPSCAN, - NULL, NULL); *bitindexpaths = list_concat(*bitindexpaths, indexpaths); } @@ -817,27 +793,19 @@ get_index_paths(PlannerInfo *root, RelOptInfo *rel, * to true if we found any such clauses (caller must initialize the variable * to false). If it's NULL, we do not ignore ScalarArrayOpExpr clauses. * - * If skip_lower_saop is non-NULL, we ignore ScalarArrayOpExpr clauses for - * non-first index columns, and we set *skip_lower_saop to true if we found - * any such clauses (caller must initialize the variable to false). If it's - * NULL, we do not ignore non-first ScalarArrayOpExpr clauses, but they will - * result in considering the scan's output to be unordered. - * * 'rel' is the index's heap relation * 'index' is the index for which we want to generate paths * 'clauses' is the collection of indexable clauses (IndexClause nodes) * 'useful_predicate' indicates whether the index has a useful predicate * 'scantype' indicates whether we need plain or bitmap scan support * 'skip_nonnative_saop' indicates whether to accept SAOP if index AM doesn't - * 'skip_lower_saop' indicates whether to accept non-first-column SAOP */ static List * build_index_paths(PlannerInfo *root, RelOptInfo *rel, IndexOptInfo *index, IndexClauseSet *clauses, bool useful_predicate, ScanTypeControl scantype, - bool *skip_nonnative_saop, - bool *skip_lower_saop) + bool *skip_nonnative_saop) { List *result = NIL; IndexPath *ipath; @@ -848,12 +816,13 @@ build_index_paths(PlannerInfo *root, RelOptInfo *rel, List *orderbyclausecols; List *index_pathkeys; List *useful_pathkeys; - bool found_lower_saop_clause; bool pathkeys_possibly_useful; bool index_is_ordered; bool index_only_scan; int indexcol; + Assert(skip_nonnative_saop != NULL || scantype == ST_BITMAPSCAN); + /* * Check that index supports the desired scan type(s) */ @@ -880,19 +849,11 @@ build_index_paths(PlannerInfo *root, RelOptInfo *rel, * on by btree and possibly other places.) The list can be empty, if the * index AM allows that. * - * found_lower_saop_clause is set true if we accept a ScalarArrayOpExpr - * index clause for a non-first index column. This prevents us from - * assuming that the scan result is ordered. (Actually, the result is - * still ordered if there are equality constraints for all earlier - * columns, but it seems too expensive and non-modular for this code to be - * aware of that refinement.) - * * We also build a Relids set showing which outer rels are required by the * selected clauses. Any lateral_relids are included in that, but not * otherwise accounted for. */ index_clauses = NIL; - found_lower_saop_clause = false; outer_relids = bms_copy(rel->lateral_relids); for (indexcol = 0; indexcol < index->nkeycolumns; indexcol++) { @@ -903,30 +864,18 @@ build_index_paths(PlannerInfo *root, RelOptInfo *rel, IndexClause *iclause = (IndexClause *) lfirst(lc); RestrictInfo *rinfo = iclause->rinfo; - /* We might need to omit ScalarArrayOpExpr clauses */ - if (IsA(rinfo->clause, ScalarArrayOpExpr)) + if (skip_nonnative_saop && !index->amsearcharray && + IsA(rinfo->clause, ScalarArrayOpExpr)) { - if (!index->amsearcharray) - { - if (skip_nonnative_saop) - { - /* Ignore because not supported by index */ - *skip_nonnative_saop = true; - continue; - } - /* Caller had better intend this only for bitmap scan */ - Assert(scantype == ST_BITMAPSCAN); - } - if (indexcol > 0) - { - if (skip_lower_saop) - { - /* Caller doesn't want to lose index ordering */ - *skip_lower_saop = true; - continue; - } - found_lower_saop_clause = true; - } + /* + * Caller asked us to generate IndexPaths that omit any + * ScalarArrayOpExpr clauses when the underlying index AM + * lacks native support. + * + * We must omit this clause (and tell caller about it). + */ + *skip_nonnative_saop = true; + continue; } /* OK to include this clause */ @@ -956,11 +905,9 @@ build_index_paths(PlannerInfo *root, RelOptInfo *rel, /* * 2. Compute pathkeys describing index's ordering, if any, then see how * many of them are actually useful for this query. This is not relevant - * if we are only trying to build bitmap indexscans, nor if we have to - * assume the scan is unordered. + * if we are only trying to build bitmap indexscans. */ pathkeys_possibly_useful = (scantype != ST_BITMAPSCAN && - !found_lower_saop_clause && has_useful_pathkeys(root, rel)); index_is_ordered = (index->sortopfamily != NULL); if (index_is_ordered && pathkeys_possibly_useful) @@ -1212,7 +1159,6 @@ build_paths_for_OR(PlannerInfo *root, RelOptInfo *rel, index, &clauseset, useful_predicate, ST_BITMAPSCAN, - NULL, NULL); result = list_concat(result, indexpaths); } |