Fix ALTER COLUMN TYPE to preserve the tablespace and reloptions of indexes

it affects.  The original coding neglected tablespace entirely (causing
the indexes to move to the database's default tablespace) and for an index
belonging to a UNIQUE or PRIMARY KEY constraint, it would actually try to
assign the parent table's reloptions to the index :-(.  Per bug #3672 and
subsequent investigation.

8.0 and 8.1 did not have reloptions, but the tablespace bug is present.

1 files changed, 30 insertions, 1 deletions

diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index b15f0f61fb7..e81f89c662c 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/cache/lsyscache.c,v 1.119 2004/12/31 22:01:25 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/cache/lsyscache.c,v 1.119.4.1 2007/10/13 15:56:08 tgl Exp $
  *
  * NOTES
  *	  Eventually, the index information should go through here, too.
@@ -1040,6 +1040,35 @@ get_rel_relkind(Oid relid)
 		return '\0';
 }
 
+/*
+ * get_rel_tablespace
+ *
+ *		Returns the pg_tablespace OID associated with a given relation.
+ *
+ * Note: InvalidOid might mean either that we couldn't find the relation,
+ * or that it is in the database's default tablespace.
+ */
+Oid
+get_rel_tablespace(Oid relid)
+{
+	HeapTuple	tp;
+
+	tp = SearchSysCache(RELOID,
+						ObjectIdGetDatum(relid),
+						0, 0, 0);
+	if (HeapTupleIsValid(tp))
+	{
+		Form_pg_class reltup = (Form_pg_class) GETSTRUCT(tp);
+		Oid			result;
+
+		result = reltup->reltablespace;
+		ReleaseSysCache(tp);
+		return result;
+	}
+	else
+		return InvalidOid;
+}
+
 
 /*				---------- TYPE CACHE ----------						 */