Revise hash join and hash aggregation code to use the same datatype-

specific hash functions used by hash indexes, rather than the old
not-datatype-aware ComputeHashFunc routine.  This makes it safe to do
hash joining on several datatypes that previously couldn't use hashing.
The sets of datatypes that are hash indexable and hash joinable are now
exactly the same, whereas before each had some that weren't in the other.

1 files changed, 20 insertions, 15 deletions

diff --git a/src/backend/executor/nodeHash.c b/src/backend/executor/nodeHash.c
index b338c8961e2..f00cc28684d 100644
--- a/src/backend/executor/nodeHash.c
+++ b/src/backend/executor/nodeHash.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeHash.c,v 1.75 2003/03/27 16:51:27 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/nodeHash.c,v 1.76 2003/06/22 22:04:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -192,7 +192,7 @@ ExecEndHash(HashState *node)
  * ----------------------------------------------------------------
  */
 HashJoinTable
-ExecHashTableCreate(Hash *node)
+ExecHashTableCreate(Hash *node, List *hashOperators)
 {
 	HashJoinTable hashtable;
 	Plan	   *outerNode;
@@ -201,7 +201,7 @@ ExecHashTableCreate(Hash *node)
 	int			nbatch;
 	int			nkeys;
 	int			i;
-	List	   *hk;
+	List	   *ho;
 	MemoryContext oldcxt;
 
 	/*
@@ -237,17 +237,20 @@ ExecHashTableCreate(Hash *node)
 	hashtable->outerBatchSize = NULL;
 
 	/*
-	 * Get info about the datatypes of the hash keys.
+	 * Get info about the hash functions to be used for each hash key.
 	 */
-	nkeys = length(node->hashkeys);
-	hashtable->typLens = (int16 *) palloc(nkeys * sizeof(int16));
-	hashtable->typByVals = (bool *) palloc(nkeys * sizeof(bool));
+	nkeys = length(hashOperators);
+	hashtable->hashfunctions = (FmgrInfo *) palloc(nkeys * sizeof(FmgrInfo));
 	i = 0;
-	foreach(hk, node->hashkeys)
+	foreach(ho, hashOperators)
 	{
-		get_typlenbyval(exprType(lfirst(hk)),
-						&hashtable->typLens[i],
-						&hashtable->typByVals[i]);
+		Oid		hashfn;
+
+		hashfn = get_op_hash_function(lfirsto(ho));
+		if (!OidIsValid(hashfn))
+			elog(ERROR, "Could not find hash function for hash operator %u",
+				 lfirsto(ho));
+		fmgr_info(hashfn, &hashtable->hashfunctions[i]);
 		i++;
 	}
 
@@ -520,7 +523,7 @@ ExecHashGetBucket(HashJoinTable hashtable,
 
 	/*
 	 * We reset the eval context each time to reclaim any memory leaked in
-	 * the hashkey expressions or ComputeHashFunc itself.
+	 * the hashkey expressions.
 	 */
 	ResetExprContext(econtext);
 
@@ -545,9 +548,11 @@ ExecHashGetBucket(HashJoinTable hashtable,
 		 */
 		if (!isNull)			/* treat nulls as having hash key 0 */
 		{
-			hashkey ^= ComputeHashFunc(keyval,
-									   (int) hashtable->typLens[i],
-									   hashtable->typByVals[i]);
+			uint32		hkey;
+
+			hkey = DatumGetUInt32(FunctionCall1(&hashtable->hashfunctions[i],
+												keyval));
+			hashkey ^= hkey;
 		}
 
 		i++;