Per Tatsuo's recommendation, change mdopen so that it won't

automatically create the file, except during bootstrap mode where that
seems to be necessary.

src/backend/storage/smgr/md.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/smgr/md.c,v 1.52 1999/09/02 02:57:49 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/smgr/md.c,v 1.53 1999/09/05 23:24:53 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -284,13 +284,23 @@ mdopen(Relation reln)
 	fd = FileNameOpenFile(path, O_RDWR | O_BINARY, 0600);
 #endif
 
-	/* this should only happen during bootstrap processing */
 	if (fd < 0)
+	{
+		/* in bootstrap mode, accept mdopen as substitute for mdcreate */
+		if (IsBootstrapProcessingMode())
+		{
 #ifndef __CYGWIN32__
-		fd = FileNameOpenFile(path, O_RDWR | O_CREAT | O_EXCL, 0600);
+			fd = FileNameOpenFile(path, O_RDWR | O_CREAT | O_EXCL, 0600);
 #else
-		fd = FileNameOpenFile(path, O_RDWR | O_CREAT | O_EXCL | O_BINARY, 0600);
+			fd = FileNameOpenFile(path, O_RDWR | O_CREAT | O_EXCL | O_BINARY, 0600);
 #endif
+		}
+		if (fd < 0)
+		{
+			elog(ERROR, "mdopen: couldn't open %s: %m", path);
+			return -1;
+		}
+	}
 
 	vfd = _fdvec_alloc();
 	if (vfd < 0)