diff options
| -rw-r--r-- | src/backend/optimizer/path/indxpath.c | 7 | ||||
| -rw-r--r-- | src/backend/optimizer/path/pathkeys.c | 21 | ||||
| -rw-r--r-- | src/include/optimizer/paths.h | 4 |
3 files changed, 20 insertions, 12 deletions
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c index a00ad764c71..4eea16a0183 100644 --- a/src/backend/optimizer/path/indxpath.c +++ b/src/backend/optimizer/path/indxpath.c @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.198 2006/01/26 02:35:49 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.199 2006/01/29 17:27:42 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -343,7 +343,8 @@ find_usable_indexes(PlannerInfo *root, RelOptInfo *rel, if (istoplevel && index_is_ordered && !isjoininner) { index_pathkeys = build_index_pathkeys(root, index, - ForwardScanDirection); + ForwardScanDirection, + true); useful_pathkeys = truncate_useless_pathkeys(root, rel, index_pathkeys); } @@ -1705,7 +1706,7 @@ match_index_to_query_keys(PlannerInfo *root, ListCell *r; /* Get the pathkeys that exactly describe the index */ - index_pathkeys = build_index_pathkeys(root, index, indexscandir); + index_pathkeys = build_index_pathkeys(root, index, indexscandir, false); /* * Can we match to the query's requested pathkeys? The inner loop skips diff --git a/src/backend/optimizer/path/pathkeys.c b/src/backend/optimizer/path/pathkeys.c index 4216768212c..dc7687916f6 100644 --- a/src/backend/optimizer/path/pathkeys.c +++ b/src/backend/optimizer/path/pathkeys.c @@ -11,7 +11,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/path/pathkeys.c,v 1.74 2005/11/22 18:17:12 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/path/pathkeys.c,v 1.75 2006/01/29 17:27:42 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -909,13 +909,20 @@ get_cheapest_fractional_path_for_pathkeys(List *paths, * If 'scandir' is BackwardScanDirection, attempt to build pathkeys * representing a backwards scan of the index. Return NIL if can't do it. * + * If 'canonical' is TRUE, we remove duplicate pathkeys (which can occur + * if two index columns are equijoined, eg WHERE x = 1 AND y = 1). This + * is required if the result is to be compared directly to a canonical query + * pathkeys list. However, some callers want a list with exactly one entry + * per index column, and they must pass FALSE. + * * We generate the full pathkeys list whether or not all are useful for the * current query. Caller should do truncate_useless_pathkeys(). */ List * build_index_pathkeys(PlannerInfo *root, IndexOptInfo *index, - ScanDirection scandir) + ScanDirection scandir, + bool canonical) { List *retval = NIL; int *indexkeys = index->indexkeys; @@ -956,11 +963,11 @@ build_index_pathkeys(PlannerInfo *root, item = makePathKeyItem(indexkey, sortop, true); cpathkey = make_canonical_pathkey(root, item); - /* - * Eliminate redundant ordering info; could happen if query is such - * that index keys are equijoined... - */ - retval = list_append_unique_ptr(retval, cpathkey); + /* Eliminate redundant ordering info if requested */ + if (canonical) + retval = list_append_unique_ptr(retval, cpathkey); + else + retval = lappend(retval, cpathkey); indexkeys++; ordering++; diff --git a/src/include/optimizer/paths.h b/src/include/optimizer/paths.h index afe3a70d71b..d9fab6ac042 100644 --- a/src/include/optimizer/paths.h +++ b/src/include/optimizer/paths.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/optimizer/paths.h,v 1.90 2005/12/20 02:30:36 tgl Exp $ + * $PostgreSQL: pgsql/src/include/optimizer/paths.h,v 1.91 2006/01/29 17:27:42 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -114,7 +114,7 @@ extern Path *get_cheapest_fractional_path_for_pathkeys(List *paths, List *pathkeys, double fraction); extern List *build_index_pathkeys(PlannerInfo *root, IndexOptInfo *index, - ScanDirection scandir); + ScanDirection scandir, bool canonical); extern List *convert_subquery_pathkeys(PlannerInfo *root, RelOptInfo *rel, List *subquery_pathkeys); extern List *build_join_pathkeys(PlannerInfo *root, |