Forgot that I had intended to replace division by masking in hash calculation.

tglsfdc · tglsfdc · commit dffbbb3e5520 · 2005-03-13T19:59:40.000Z
diff --git a/src/backend/executor/nodeHash.c b/src/backend/executor/nodeHash.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeHash.c,v 1.89 2005/03/06 22:15:04 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeHash.c,v 1.90 2005/03/13 19:59:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -709,7 +709,8 @@ ExecHashGetBucketAndBatch(HashJoinTable hashtable,
 	if (nbatch > 1)
 	{
 		*bucketno = hashvalue % nbuckets;
-		*batchno = (hashvalue / nbuckets) % nbatch;
+		/* since nbatch is a power of 2, can do MOD by masking */
+		*batchno = (hashvalue / nbuckets) & (nbatch - 1);
 	}
 	else
 	{

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/executor/nodeHash.c,v 1.89 2005/03/06 22:15:04 tgl Exp $`
	`11`	`+ * $PostgreSQL: pgsql/src/backend/executor/nodeHash.c,v 1.90 2005/03/13 19:59:40 tgl Exp $`
`12`	`12`	`*`
`13`	`13`	`*-------------------------------------------------------------------------`
`14`	`14`	`*/`
`@@ -709,7 +709,8 @@ ExecHashGetBucketAndBatch(HashJoinTable hashtable,`
`709`	`709`	`if (nbatch > 1)`
`710`	`710`	`{`
`711`	`711`	`*bucketno = hashvalue % nbuckets;`
`712`		`- *batchno = (hashvalue / nbuckets) % nbatch;`
	`712`	`+ /* since nbatch is a power of 2, can do MOD by masking */`
	`713`	`+ *batchno = (hashvalue / nbuckets) & (nbatch - 1);`
`713`	`714`	`}`
`714`	`715`	`else`
`715`	`716`	`{`