Update findoidjoins for 6.5: remove workaround for long-dead bug,

use NOT EXISTS() which is a lot faster than NOT IN (),
update documentation.

contrib/findoidjoins/make_oidjoins_check

@@ -1,17 +1,37 @@
-:
+#! /bin/sh
+
 # You first run findoidjoins on the template1 database, and send that
 # output into this file to generate a list of SQL statements.
+
+# NOTE: any field that findoidjoins thinks joins to more than one table
+# will NOT be checked by the output of this script.  You should be
+# suspicious of multiple entries in findoidjoins' output.
+
+# Caution: you may need to use GNU awk.
+AWK=${AWK:-awk}
+
 trap "rm -f /tmp/$$ /tmp/$$a /tmp/$$b" 0 1 2 3 15
 
+# Read input
 cat "$@" >/tmp/$$
+
+# Look for fields with multiple references.
 cat /tmp/$$ | cut -d' ' -f2 | sort | uniq -d >/tmp/$$a
+if [ -s /tmp/$$a ] ; then
+	echo "Ignoring these fields that link to multiple tables:" 1>&2
+	cat /tmp/$$a 1>&2
+fi
+
+# Get the non-multiply-referenced fields.
 cat /tmp/$$ | while read LINE
 do
 	set -- $LINE
 	grep "$2" /tmp/$$a >/dev/null 2>&1 || echo $LINE
 done >/tmp/$$b
+
+# Generate the output.
 cat /tmp/$$b |
-awk -F'[ \.]' '\
+$AWK -F'[ \.]' '\
 	BEGIN \
 	{
 		printf "\
@@ -23,13 +43,11 @@ awk -F'[ \.]' '\
 		printf "\
 SELECT	oid, %s.%s \n\
 FROM	%s \n\
-WHERE	%s%s.%s%s NOT IN (SELECT oid FROM %s) AND \n\
-	%s%s.%s%s != 0;\n", 	$2, $3, $2,
-				($5 == "pg_proc") ? "RegprocToOid(" : "",
-				$2, $3,
-				($5 == "pg_proc") ? ")" : "",
-				$5,
-				($5 == "pg_proc") ? "RegprocToOid(" : "",
-				$2, $3,
-				($5 == "pg_proc") ? ")" : "";
+WHERE	%s.%s != 0 AND \n\
+	NOT EXISTS(SELECT * FROM %s AS t1 WHERE t1.oid = %s.%s);\n",
+	$2, $3, $2,
+	$2, $3,
+	$5, $2, $3;
 	}'
+
+exit 0