From ebb4caa9120d5bcb047dcb5b8562d929c187174a Mon Sep 17 00:00:00 2001
From: Tomas Vondra <tomas.vondra@postgresql.org>
Date: Wed, 16 Oct 2019 13:23:14 +0200
Subject: [PATCH] Improve the check for pg_catalog.line data type in pg_upgrade

The pg_upgrade check for pg_catalog.line data type when upgrading from
9.3 had a couple of issues with domains and composite types. Firstly, it
triggered false positives for composite types unused in objects with
storage. This was enough to trigger an unnecessary pg_upgrade failure:

  CREATE TYPE line_composite AS (l pg_catalog.line)

On the other hand, this only happened with composite types directly on
the pg_catalog.line data type, but not with a domain. So this was not
detected

  CREATE DOMAIN line_domain AS pg_catalog.line;
  CREATE TYPE line_composite_2 AS (l line_domain);

unlike the first example. These false positives and inconsistencies are
unfortunate, but what's worse we've failed to detected objects using the
pg_catalog.line data type through a domain. So we missed cases like this

  CREATE TABLE t (l line_composite_2);

The consequence is clusters broken after a pg_upgrade.

This fixes these false positives and false negatives by using the same
recursive CTE introduced by eaf900e842 for sql_identifier. 9.3 did not
support domains on composite types, but we can still have multi-level
composite types.

Backpatch all the way to 9.4, where the format for pg_catalog.line data
type changed.

Author: Tomas Vondra
Backpatch-to: 9.4-
Discussion: https://postgr.es/m/16045-673e8fa6b5ace196%40postgresql.org
---
 src/bin/pg_upgrade/version.c | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/bin/pg_upgrade/version.c b/src/bin/pg_upgrade/version.c
index 701b17740d..ac488f0bf2 100644
--- a/src/bin/pg_upgrade/version.c
+++ b/src/bin/pg_upgrade/version.c
@@ -131,14 +131,42 @@ old_9_3_check_for_line_data_type_usage(ClusterInfo *cluster)
 		DbInfo	   *active_db = &cluster->dbarr.dbs[dbnum];
 		PGconn	   *conn = connectToServer(cluster, active_db->db_name);
 
+		/*
+		 * The pg_catalog.line type may be wrapped in a domain or composite
+		 * type, or both (9.3 did not allow domains on composite types, but
+		 * there may be multi-level composite type). To detect these cases
+		 * we need a recursive CTE.
+		 */
 		res = executeQueryOrDie(conn,
+								"WITH RECURSIVE oids AS ( "
+		/* the pg_catalog.line type itself */
+								"	SELECT 'pg_catalog.line'::pg_catalog.regtype AS oid "
+								"	UNION ALL "
+								"	SELECT * FROM ( "
+		/* domains on the type */
+								"		WITH x AS (SELECT oid FROM oids) "
+								"			SELECT t.oid FROM pg_catalog.pg_type t, x WHERE typbasetype = x.oid AND typtype = 'd' "
+								"			UNION "
+		/* composite types containing the type */
+								"			SELECT t.oid FROM pg_catalog.pg_type t, pg_catalog.pg_class c, pg_catalog.pg_attribute a, x "
+								"			WHERE t.typtype = 'c' AND "
+								"				  t.oid = c.reltype AND "
+								"				  c.oid = a.attrelid AND "
+								"				  NOT a.attisdropped AND "
+								"				  a.atttypid = x.oid "
+								"	) foo "
+								") "
 								"SELECT n.nspname, c.relname, a.attname "
 								"FROM	pg_catalog.pg_class c, "
 								"		pg_catalog.pg_namespace n, "
 								"		pg_catalog.pg_attribute a "
 								"WHERE	c.oid = a.attrelid AND "
 								"		NOT a.attisdropped AND "
-								"		a.atttypid = 'pg_catalog.line'::pg_catalog.regtype AND "
+								"		a.atttypid IN (SELECT oid FROM oids) AND "
+								"		c.relkind IN ("
+								CppAsString2(RELKIND_RELATION) ", "
+								CppAsString2(RELKIND_MATVIEW) ", "
+								CppAsString2(RELKIND_INDEX) ") AND "
 								"		c.relnamespace = n.oid AND "
 		/* exclude possible orphaned temp tables */
 								"		n.nspname !~ '^pg_temp_' AND "