Ignore RECHECK in CREATE OPERATOR CLASS, just throwing a NOTICE, instead of

throwing an error as 8.4 had been doing.  The error interfered with porting
old database definitions (particularly for pg_migrator) without really buying
any safety.  Per bug #4817 and subsequent discussion.

src/backend/parser/gram.y

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.663 2009/04/28 09:09:41 heikki Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.664 2009/05/27 20:42:29 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -3639,9 +3639,14 @@ opt_opfamily:	FAMILY any_name				{ $$ = $2; }
 
 opt_recheck:	RECHECK
 				{
-					ereport(ERROR,
+					/*
+					 * RECHECK no longer does anything in opclass definitions,
+					 * but we still accept it to ease porting of old database
+					 * dumps.
+					 */
+					ereport(NOTICE,
 							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-							 errmsg("RECHECK is no longer supported"),
+							 errmsg("RECHECK is no longer required"),
 							 errhint("Update your data type."),
 							 scanner_errposition(@1)));
 					$$ = TRUE;

src/bin/pg_dump/pg_dump.c

@@ -12,7 +12,7 @@
  *	by PostgreSQL
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.537 2009/05/26 17:36:05 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.538 2009/05/27 20:42:29 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -8159,8 +8159,10 @@ dumpOpclass(Archive *fout, OpclassInfo *opcinfo)
 		 * pg_depend entries.
 		 *
 		 * XXX RECHECK is gone as of 8.4, but we'll still print it if dumping
-		 * an older server's table in which it is used.  Would it be better
-		 * to silently ignore it?
+		 * an older server's opclass in which it is used.  This is to avoid
+		 * hard-to-detect breakage if a newer pg_dump is used to dump from
+		 * an older server and then reload into that old version.  This can
+		 * go away once 8.3 is so old as to not be of interest to anyone.
 		 */
 		appendPQExpBuffer(query, "SELECT amopstrategy, false AS amopreqcheck, "
 						  "amopopr::pg_catalog.regoperator "
@@ -8370,8 +8372,10 @@ dumpOpfamily(Archive *fout, OpfamilyInfo *opfinfo)
 	{
 		/*
 		 * XXX RECHECK is gone as of 8.4, but we'll still print it if dumping
-		 * an older server's table in which it is used.  Would it be better
-		 * to silently ignore it?
+		 * an older server's opclass in which it is used.  This is to avoid
+		 * hard-to-detect breakage if a newer pg_dump is used to dump from
+		 * an older server and then reload into that old version.  This can
+		 * go away once 8.3 is so old as to not be of interest to anyone.
 		 */
 		appendPQExpBuffer(query, "SELECT amopstrategy, false AS amopreqcheck, "
 					  "amopopr::pg_catalog.regoperator "