Fix oversight in 8.0 modification of RestrictInfo data structures.

tglsfdc · tglsfdc · commit 07e6f93d6b41 · 2005-10-11T16:44:40.000Z
A RestrictInfo representing an OR clause now contains two versions of
the contained expression, one with sub-RestrictInfos and one without.
clause_selectivity() should descend to the version with sub-RestrictInfos
so that it has a chance of caching its results for the OR's sub-clauses.
Failing to do so resulted in redundant planner effort.
diff --git a/src/backend/optimizer/path/clausesel.c b/src/backend/optimizer/path/clausesel.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/path/clausesel.c,v 1.73 2005/06/05 22:32:55 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/path/clausesel.c,v 1.74 2005/10/11 16:44:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -461,8 +461,15 @@ clause_selectivity(PlannerInfo *root,
 			}
 		}
 
-		/* Proceed with examination of contained clause */
-		clause = (Node *) rinfo->clause;
+		/*
+		 * Proceed with examination of contained clause.  If the clause is an
+		 * OR-clause, we want to look at the variant with sub-RestrictInfos,
+		 * so that per-subclause selectivities can be cached.
+		 */
+		if (rinfo->orclause)
+			clause = (Node *) rinfo->orclause;
+		else
+			clause = (Node *) rinfo->clause;
 	}
 
 	if (IsA(clause, Var))

Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,7 @@`
`8`	`8`	`*`
`9`	`9`	`*`
`10`	`10`	`* IDENTIFICATION`
`11`		`- * $PostgreSQL: pgsql/src/backend/optimizer/path/clausesel.c,v 1.73 2005/06/05 22:32:55 tgl Exp $`
	`11`	`+ * $PostgreSQL: pgsql/src/backend/optimizer/path/clausesel.c,v 1.74 2005/10/11 16:44:40 tgl Exp $`
`12`	`12`	`*`
`13`	`13`	`*-------------------------------------------------------------------------`
`14`	`14`	`*/`
`@@ -461,8 +461,15 @@ clause_selectivity(PlannerInfo *root,`
`461`	`461`	`}`
`462`	`462`	`}`
`463`	`463`
`464`		`- /* Proceed with examination of contained clause */`
`465`		`- clause = (Node *) rinfo->clause;`
	`464`	`+ /*`
	`465`	`+ * Proceed with examination of contained clause. If the clause is an`
	`466`	`+ * OR-clause, we want to look at the variant with sub-RestrictInfos,`
	`467`	`+ * so that per-subclause selectivities can be cached.`
	`468`	`+ */`
	`469`	`+ if (rinfo->orclause)`
	`470`	`+ clause = (Node *) rinfo->orclause;`
	`471`	`+ else`
	`472`	`+ clause = (Node *) rinfo->clause;`
`466`	`473`	`}`
`467`	`474`
`468`	`475`	`if (IsA(clause, Var))`