diff options
Diffstat (limited to 'src/backend/optimizer/path/indxpath.c')
| -rw-r--r-- | src/backend/optimizer/path/indxpath.c | 44 |
1 files changed, 40 insertions, 4 deletions
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c index 6af480629e2..68fb4eda07e 100644 --- a/src/backend/optimizer/path/indxpath.c +++ b/src/backend/optimizer/path/indxpath.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.70 1999/08/21 03:49:00 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.71 1999/09/13 00:17:19 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -48,6 +48,9 @@ static void match_index_orclauses(RelOptInfo *rel, RelOptInfo *index, int indexk int xclass, List *restrictinfo_list); static List *match_index_orclause(RelOptInfo *rel, RelOptInfo *index, int indexkey, int xclass, List *or_clauses, List *other_matching_indices); +static bool match_or_subclause_to_indexkey(RelOptInfo *rel, RelOptInfo *index, + int indexkey, int xclass, + Expr *clause); static List *group_clauses_by_indexkey(RelOptInfo *rel, RelOptInfo *index, int *indexkeys, Oid *classes, List *restrictinfo_list); static List *group_clauses_by_ikey_for_joins(RelOptInfo *rel, RelOptInfo *index, @@ -327,8 +330,8 @@ match_index_orclause(RelOptInfo *rel, { Expr *clause = lfirst(clist); - if (match_clause_to_indexkey(rel, index, indexkey, xclass, - clause, false)) + if (match_or_subclause_to_indexkey(rel, index, indexkey, xclass, + clause)) { /* OK to add this index to sublist for this subclause */ lfirst(matching_indices) = lcons(index, @@ -341,6 +344,38 @@ match_index_orclause(RelOptInfo *rel, return index_list; } +/* + * See if a subclause of an OR clause matches an index. + * + * We accept the subclause if it is an operator clause that matches the + * index, or if it is an AND clause all of whose members are operators + * that match the index. (XXX Would accepting a single match be useful?) + */ +static bool +match_or_subclause_to_indexkey(RelOptInfo *rel, + RelOptInfo *index, + int indexkey, + int xclass, + Expr *clause) +{ + if (and_clause((Node *) clause)) + { + List *item; + + foreach(item, clause->args) + { + if (! match_clause_to_indexkey(rel, index, indexkey, xclass, + lfirst(item), false)) + return false; + } + return true; + } + else + return match_clause_to_indexkey(rel, index, indexkey, xclass, + clause, false); +} + + /**************************************************************************** * ---- ROUTINES TO CHECK RESTRICTIONS ---- ****************************************************************************/ @@ -559,7 +594,8 @@ group_clauses_by_ikey_for_joins(RelOptInfo *rel, * * Returns true if the clause can be used with this index key. * - * NOTE: returns false if clause is an or_clause; that's handled elsewhere. + * NOTE: returns false if clause is an OR or AND clause; to the extent + * we cope with those at all, it is done by higher-level routines. */ static bool match_clause_to_indexkey(RelOptInfo *rel, |