Feedback-ID: ia2694551:Fastmail
Date: Fri, 22 Sep 2023 13:14:23 +0200
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Bruce Momjian <bruce@momjian.us>,
	Pg Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: pg_upgrade --check fails to warn about abstime
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On 2023-Sep-21, Tom Lane wrote:

> Bruce Momjian <bruce@momjian.us> writes:

> > Wow, I never added code to pg_upgrade to check for that, and no one
> > complained either.
> 
> Yeah, so most people had indeed listened to warnings and moved away
> from those datatypes.  I'm inclined to think that adding code for this
> at this point is a bit of a waste of time.

The migrations from versions prior to 12 have not stopped yet, and I did
receive a complaint about it.  Because the change is so simple, I'm
inclined to patch it anyway, late though it is.

I decided to follow Tristan's advice to add the version number as a
parameter to the new function; this way, the knowledge of where was what
dropped is all in the callsite and none in the function.  It
looked a bit schizoid otherwise.

-- 
Álvaro Herrera               48°01'N 7°57'E  —  https://www.EnterpriseDB.com/
"Postgres is bloatware by design: it was built to house
 PhD theses." (Joey Hellerstein, SIGMOD annual conference 2002)

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	filename="v2-0001-pg_upgrade-check-for-types-removed-in-pg12.patch"

From 5258379693db55618c6451ce8df4971521eb8e66 Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: Tue, 19 Sep 2023 12:30:11 +0200
Subject: [PATCH v2] pg_upgrade: check for types removed in pg12

Commit cda6a8d01d39 removed a few datatypes, but didn't update
pg_upgrade --check to throw error if these types are used.  So the users
find that pg_upgrade --check tells them that everything is fine, only to
fail when the real upgrade is attempted.
---
 src/bin/pg_upgrade/check.c | 51 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 50 insertions(+), 1 deletion(-)

diff --git a/src/bin/pg_upgrade/check.c b/src/bin/pg_upgrade/check.c
index 56e313f562..21a0ff9e42 100644
--- a/src/bin/pg_upgrade/check.c
+++ b/src/bin/pg_upgrade/check.c
@@ -26,6 +26,9 @@ static void check_for_tables_with_oids(ClusterInfo *cluster);
 static void check_for_composite_data_type_usage(ClusterInfo *cluster);
 static void check_for_reg_data_type_usage(ClusterInfo *cluster);
 static void check_for_aclitem_data_type_usage(ClusterInfo *cluster);
+static void check_for_removed_data_type_usage(ClusterInfo *cluster,
+											  const char *version,
+											  const char *datatype);
 static void check_for_jsonb_9_4_usage(ClusterInfo *cluster);
 static void check_for_pg_role_prefix(ClusterInfo *cluster);
 static void check_for_new_tablespace_dir(void);
@@ -111,6 +114,16 @@ check_and_dump_old_cluster(bool live_check)
 	if (GET_MAJOR_VERSION(old_cluster.major_version) <= 1500)
 		check_for_aclitem_data_type_usage(&old_cluster);
 
+	/*
+	 * PG 12 removed types abstime, reltime, tinterval.
+	 */
+	if (GET_MAJOR_VERSION(old_cluster.major_version) <= 1100)
+	{
+		check_for_removed_data_type_usage(&old_cluster, "12", "abstime");
+		check_for_removed_data_type_usage(&old_cluster, "12", "reltime");
+		check_for_removed_data_type_usage(&old_cluster, "12", "tinterval");
+	}
+
 	/*
 	 * PG 14 changed the function signature of encoding conversion functions.
 	 * Conversions from older versions cannot be upgraded automatically
@@ -1215,7 +1228,8 @@ check_for_aclitem_data_type_usage(ClusterInfo *cluster)
 {
 	char		output_path[MAXPGPATH];
 
-	prep_status("Checking for incompatible \"aclitem\" data type in user tables");
+	prep_status("Checking for incompatible \"%s\" data type in user tables",
+				"aclitem");
 
 	snprintf(output_path, sizeof(output_path), "tables_using_aclitem.txt");
 
@@ -1233,6 +1247,41 @@ check_for_aclitem_data_type_usage(ClusterInfo *cluster)
 		check_ok();
 }
 
+/*
+ * check_for_removed_data_type_usage
+ *
+ *	Check for in-core data types that have been removed.  Callers know
+ *	the exact list.
+ */
+static void
+check_for_removed_data_type_usage(ClusterInfo *cluster, const char *version,
+								  const char *datatype)
+{
+	char		output_path[MAXPGPATH];
+	char		typename[NAMEDATALEN];
+
+	prep_status("Checking for removed \"%s\" data type in user tables",
+				datatype);
+
+	snprintf(output_path, sizeof(output_path), "tables_using_%s.txt",
+			 datatype);
+	snprintf(typename, sizeof(typename), "pg_catalog.%s", datatype);
+
+	if (check_for_data_type_usage(cluster, typename, output_path))
+	{
+		pg_log(PG_REPORT, "fatal");
+		pg_fatal("Your installation contains the \"%s\" data type in user tables.\n"
+				 "The \"%s\" type has been removed in PostgreSQL version %s,\n"
+				 "so this cluster cannot currently be upgraded.  You can drop the\n"
+				 "problem columns, or change them to another data type, and restart\n"
+				 "the upgrade.  A list of the problem columns is in the file:\n"
+				 "    %s", datatype, datatype, version, output_path);
+	}
+	else
+		check_ok();
+}
+
+
 /*
  * check_for_jsonb_9_4_usage()
  *
-- 
2.39.2


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