From 6c51d5f403e7be515686662f930d6ffbc1af74b1 Mon Sep 17 00:00:00 2001
From: aykut-bozkurt <51649454+aykut-bozkurt@users.noreply.github.com>
Date: Fri, 21 Oct 2022 14:32:42 +0300
Subject: [PATCH] Drop worker_fetch_foreign_file/worker_repartition_cleanup
 only if they exist when upgrading Citus (#6441)

We should not introduce breaking sql changes to upgrade files after they
are released. We did that for worker_fetch_foreign_file in v9.0.0 and
worker_repartition_cleanup in v9.2.0. Later when we try to drop those
udfs, they were missing for some clients unexpectedly due to breaking
change in an old upgrade script. For that case, the fix is to add DROP
IF EXISTS for those 2 udfs in 11.0-4--11.1-1.

(cherry picked from commit 162c8a516089d13f35d42fcbc51b8e314eacde62)
---
 .../distributed/sql/citus--11.0-4--11.1-1.sql       | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/backend/distributed/sql/citus--11.0-4--11.1-1.sql b/src/backend/distributed/sql/citus--11.0-4--11.1-1.sql
index 363ddad3c..53d476eac 100644
--- a/src/backend/distributed/sql/citus--11.0-4--11.1-1.sql
+++ b/src/backend/distributed/sql/citus--11.0-4--11.1-1.sql
@@ -5,14 +5,23 @@
 #include "udfs/citus_internal_delete_partition_metadata/11.1-1.sql"
 #include "udfs/citus_copy_shard_placement/11.1-1.sql"
 
+-- We should not introduce breaking sql changes to upgrade files after they are released.
+-- We did that for worker_fetch_foreign_file in v9.0.0 and worker_repartition_cleanup in v9.2.0.
+-- When we try to drop those udfs in that file, they were missing for some clients unexpectedly
+-- due to buggy changes in old upgrade scripts. For that case, the fix is to change DROP statements
+-- with DROP IF EXISTS for those 2 udfs in 11.0-4--11.1-1.
+-- Fixes an upgrade problem for worker_fetch_foreign_file when upgrade starts from 8.3 up to 11.1
+-- Fixes an upgrade problem for worker_repartition_cleanup when upgrade starts from 9.1 up to 11.1
+-- Refer the related PR https://github.com/citusdata/citus/pull/6441 for more information
+DROP FUNCTION IF EXISTS pg_catalog.worker_fetch_foreign_file(text, text, bigint, text[], integer[]);
+DROP FUNCTION IF EXISTS pg_catalog.worker_repartition_cleanup(bigint);
+
 DROP FUNCTION pg_catalog.worker_create_schema(bigint,text);
 DROP FUNCTION pg_catalog.worker_cleanup_job_schema_cache();
-DROP FUNCTION pg_catalog.worker_fetch_foreign_file(text, text, bigint, text[], integer[]);
 DROP FUNCTION pg_catalog.worker_fetch_partition_file(bigint, integer, integer, integer, text, integer);
 DROP FUNCTION pg_catalog.worker_hash_partition_table(bigint, integer, text, text, oid, anyarray);
 DROP FUNCTION pg_catalog.worker_merge_files_into_table(bigint, integer, text[], text[]);
 DROP FUNCTION pg_catalog.worker_range_partition_table(bigint, integer, text, text, oid, anyarray);
-DROP FUNCTION pg_catalog.worker_repartition_cleanup(bigint);
 
 DO $check_columnar$
 BEGIN