Date: Tue, 15 Oct 2019 02:18:17 +0200
From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andres Freund <andres@anarazel.de>, buschmann@nidsa.net,
	pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #16045: vacuum_db crash and illegal memory alloc after
 pg_upgrade from PG11 to PG12
Message-ID: <20191015001817.zei45apgpu5dzngr@development>
References: <20191010134303.bkwjzchjb2w66iro@development>
 <30706.1570717152@sss.pgh.pa.us>
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 <20191010204022.6hiiubm2cueu3ghk@development>
 <20191013001032.lqrn4kqaovhrf77l@development>
 <17717.1570991208@sss.pgh.pa.us>
 <20191013203848.2eksimmpux3546wr@development>
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On Mon, Oct 14, 2019 at 06:35:38PM +0200, Tomas Vondra wrote:
> ...
>
>Aha! I forgot we copy the necessary stuff into pg_attribute. Thanks for
>clarifying, I'll polish and push the fix shortly.
>

I've pushed and backpatched the fix. Attached are similar fixes for the
existing pg_upgrade checks for pg_catalog.line and pg_catalog.unknown
types, which have the same issues with composite types and domains.

There are some additional details & examples in the commit messages.

I've kept this in two patches primarily because of backpatching - the
line fix should go back up to 9.4, the unknown is for 10.

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

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From 52821ea02fca502ff070508ee7be278563117509 Mon Sep 17 00:00:00 2001
From: Tomas Vondra <tv@fuzzy.cz>
Date: Tue, 15 Oct 2019 01:16:21 +0200
Subject: [PATCH 1/2] Correct the check for pg_catalog.line in pg_upgrade

The pg_upgrade check for pg_catalog.line data type when upgrading from
9.3 had a number of issues with domains and composite types. Firstly, it
detected even composite types unused in objects with storage. So for
example this was enough to trigger 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. What's worse, we have not detected this even
when used in a table. So we missed cases like this:

  CREATE TABLE t (l line_composite_2);

This fixes these false positives and false negatives by adopting the same
recursive CTE introduced by eaf900e842 for sql_identifier. Backpatch all
the way to 9.4, where the storage 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 | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/bin/pg_upgrade/version.c b/src/bin/pg_upgrade/version.c
index 8375a46454..cfe69ea554 100644
--- a/src/bin/pg_upgrade/version.c
+++ b/src/bin/pg_upgrade/version.c
@@ -131,14 +131,41 @@ 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);
 
+		/*
+		 * We need the recursive CTE because the pg_catalog.line may be wrapped
+		 * either 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).
+		 */
 		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 "
-- 
2.21.0


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From de98ca82812798e6b7392196fdcf34dff8a78133 Mon Sep 17 00:00:00 2001
From: Tomas Vondra <tv@fuzzy.cz>
Date: Tue, 15 Oct 2019 01:16:47 +0200
Subject: [PATCH 2/2] Correct the check for pg_catalog.unknown in pg_upgrade

The pg_upgrade check for pg_catalog.unknown type when upgrading from 9.6
had a couple of issues with domains and composite types. Firstly, it
detected even composite types unused in objects with storage. So for
example this was enough to trigger pg_upgrade failure:

  CREATE TYPE unknown_composite AS (u pg_catalog.unknown)

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

  CREATE DOMAIN unknown_domain AS pg_catalog.unknown;
  CREATE TYPE unknown_composite_2 AS (u unknown_domain);

unlike the first example. What's worse, we have not detected this even
when used in a table. So we missed cases like this:

  CREATE TABLE t (u unknown_composite_2);

This fixes these false positives and false negatives by using the same
recursive CTE introduced by eaf900e842 for sql_identifier. Backpatch all
the way to 10, where the of pg_catalog.unknown data type was restricted.

Author: Tomas Vondra
Backpatch-to: 10-
Discussion: https://postgr.es/m/16045-673e8fa6b5ace196%40postgresql.org
---
 src/bin/pg_upgrade/version.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/src/bin/pg_upgrade/version.c b/src/bin/pg_upgrade/version.c
index cfe69ea554..ccfb83c7eb 100644
--- a/src/bin/pg_upgrade/version.c
+++ b/src/bin/pg_upgrade/version.c
@@ -256,16 +256,33 @@ old_9_6_check_for_unknown_data_type_usage(ClusterInfo *cluster)
 		PGconn	   *conn = connectToServer(cluster, active_db->db_name);
 
 		res = executeQueryOrDie(conn,
+								"WITH RECURSIVE oids AS ( "
+		/* the sql_identifier type itself */
+								"	SELECT 'pg_catalog.unknown'::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.unknown'::pg_catalog.regtype AND "
+								"		a.atttypid IN (SELECT oid FROM oids) AND "
 								"		c.relkind IN ("
 								CppAsString2(RELKIND_RELATION) ", "
-								CppAsString2(RELKIND_COMPOSITE_TYPE) ", "
 								CppAsString2(RELKIND_MATVIEW) ") AND "
 								"		c.relnamespace = n.oid AND "
 		/* exclude possible orphaned temp tables */
-- 
2.21.0


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