Expand the 'special index operator' machinery to handle special cases

for boolean indexes.  Previously we would only use such an index with
WHERE clauses like 'indexkey = true' or 'indexkey = false'.  The new
code transforms the cases 'indexkey', 'NOT indexkey', 'indexkey IS TRUE',
and 'indexkey IS FALSE' into one of these.  While this is only marginally
useful in itself, I intend soon to change constant-expression simplification
so that 'foo = true' and 'foo = false' are reduced to just 'foo' and
'NOT foo' ... which would lose the ability to use boolean indexes for
such queries at all, if the indexscan machinery couldn't make the
reverse transformation.

src/backend/optimizer/path/orindxpath.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/path/orindxpath.c,v 1.65 2005/03/01 01:40:05 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/path/orindxpath.c,v 1.66 2005/03/26 23:29:17 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -398,7 +398,7 @@ best_or_subclause_index(Query *root,
 			continue;
 
 		/* Convert clauses to indexquals the executor can handle */
-		indexquals = expand_indexqual_conditions(index, indexclauses);
+		indexquals = expand_indexqual_conditions(rel, index, indexclauses);
 
 		cost_index(&subclause_path, root, rel, index, indexquals, false);
 

src/backend/optimizer/util/pathnode.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/pathnode.c,v 1.112 2005/03/10 23:21:22 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/pathnode.c,v 1.113 2005/03/26 23:29:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -444,7 +444,7 @@ create_index_path(Query *root,
 	pathnode->path.pathkeys = pathkeys;
 
 	/* Convert clauses to indexquals the executor can handle */
-	indexquals = expand_indexqual_conditions(index, restriction_clauses);
+	indexquals = expand_indexqual_conditions(rel, index, restriction_clauses);
 
 	/* Flatten the clause-groups list to produce indexclauses list */
 	restriction_clauses = flatten_clausegroups_list(restriction_clauses);

src/include/catalog/pg_opclass.h

@@ -27,7 +27,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_opclass.h,v 1.62 2004/12/31 22:03:24 pgsql Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_opclass.h,v 1.63 2005/03/26 23:29:19 tgl Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -92,6 +92,7 @@ DATA(insert OID =  397 (	403		array_ops		PGNSP PGUID 2277 t 0 ));
 #define ARRAY_BTREE_OPS_OID 397
 DATA(insert OID =  423 (	403		bit_ops			PGNSP PGUID 1560 t 0 ));
 DATA(insert OID =  424 (	403		bool_ops		PGNSP PGUID   16 t 0 ));
+#define BOOL_BTREE_OPS_OID 424
 DATA(insert OID =  425 (	402		box_ops			PGNSP PGUID  603 t 0 ));
 DATA(insert OID =  426 (	403		bpchar_ops		PGNSP PGUID 1042 t 0 ));
 #define BPCHAR_BTREE_OPS_OID 426
@@ -159,6 +160,7 @@ DATA(insert OID = 2098 (	403		name_pattern_ops	PGNSP PGUID   19 f 0 ));
 #define NAME_PATTERN_BTREE_OPS_OID 2098
 DATA(insert OID = 2099 (	403		money_ops		PGNSP PGUID  790 t 0 ));
 DATA(insert OID = 2222 (	405		bool_ops		PGNSP PGUID   16 t 0 ));
+#define BOOL_HASH_OPS_OID 2222
 DATA(insert OID = 2223 (	405		bytea_ops		PGNSP PGUID   17 t 0 ));
 DATA(insert OID = 2224 (	405		int2vector_ops	PGNSP PGUID   22 t 0 ));
 DATA(insert OID = 2225 (	405		xid_ops			PGNSP PGUID   28 t 0 ));

src/include/optimizer/paths.h

@@ -8,7 +8,7 @@
  * 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 1.78 2005/01/23 02:21:36 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/optimizer/paths.h,v 1.79 2005/03/26 23:29:20 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -41,8 +41,9 @@ extern Path *best_inner_indexscan(Query *root, RelOptInfo *rel,
 extern List *group_clauses_by_indexkey_for_or(RelOptInfo *rel,
 								 IndexOptInfo *index,
 								 Expr *orsubclause);
-extern List *expand_indexqual_conditions(IndexOptInfo *index,
-							List *clausegroups);
+extern List *expand_indexqual_conditions(RelOptInfo *rel,
+										 IndexOptInfo *index,
+										 List *clausegroups);
 extern void check_partial_indexes(Query *root, RelOptInfo *rel);
 extern bool pred_test(List *predicate_list, List *restrictinfo_list);
 extern List *flatten_clausegroups_list(List *clausegroups);