Change SearchSysCache coding conventions so that a reference count is

maintained for each cache entry.  A cache entry will not be freed until
the matching ReleaseSysCache call has been executed.  This eliminates
worries about cache entries getting dropped while still in use.  See
my posting to pg-hackers of even date for more info.

src/backend/executor/nodeHash.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *
- *	$Id: nodeHash.c,v 1.52 2000/08/24 03:29:03 tgl Exp $
+ *	$Id: nodeHash.c,v 1.53 2000/11/16 22:30:22 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -29,8 +29,8 @@
 #include "executor/nodeHashjoin.h"
 #include "miscadmin.h"
 #include "parser/parse_expr.h"
-#include "parser/parse_type.h"
 #include "utils/memutils.h"
+#include "utils/lsyscache.h"
 
 
 static int	hashFunc(Datum key, int len, bool byVal);
@@ -237,7 +237,6 @@ ExecHashTableCreate(Hash *node)
 	int			totalbuckets;
 	int			bucketsize;
 	int			i;
-	Type		typeInfo;
 	MemoryContext oldcxt;
 
 	/* ----------------
@@ -353,9 +352,9 @@ ExecHashTableCreate(Hash *node)
 	 *	Get info about the datatype of the hash key.
 	 * ----------------
 	 */
-	typeInfo = typeidType(exprType(node->hashkey));
-	hashtable->typByVal = typeByVal(typeInfo);
-	hashtable->typLen = typeLen(typeInfo);
+	get_typlenbyval(exprType(node->hashkey),
+					&hashtable->typLen,
+					&hashtable->typByVal);
 
 	/* ----------------
 	 *	Create temporary memory contexts in which to keep the hashtable
@@ -546,7 +545,9 @@ ExecHashGetBucket(HashJoinTable hashtable,
 	}
 	else
 	{
-		bucketno = hashFunc(keyval, hashtable->typLen, hashtable->typByVal)
+		bucketno = hashFunc(keyval,
+							(int) hashtable->typLen,
+							hashtable->typByVal)
 			% hashtable->totalbuckets;
 	}