Fix index name udf scripts for 10.2 and bump use of new sql functions

src/backend/distributed/citus.control

@@ -1,6 +1,6 @@
 # Citus extension
 comment = 'Citus distributed database'
-default_version = '10.2-3'
+default_version = '10.2-4'
 module_pathname = '$libdir/citus'
 relocatable = false
 schema = pg_catalog

src/backend/distributed/sql/citus--10.2-3--10.2-4.sql

@@ -0,0 +1,7 @@
+-- citus--10.2-3--10.2-4
+
+-- bump version to 10.2-4
+
+#include "udfs/fix_partition_shard_index_names/10.2-4.sql"
+#include "udfs/fix_all_partition_shard_index_names/10.2-4.sql"
+#include "udfs/worker_fix_partition_shard_index_names/10.2-4.sql"

src/backend/distributed/sql/downgrades/citus--10.2-4--10.2-3.sql

@@ -0,0 +1,5 @@
+-- citus--10.2-4--10.2-3
+
+DROP FUNCTION pg_catalog.fix_all_partition_shard_index_names();
+DROP FUNCTION pg_catalog.fix_partition_shard_index_names(regclass);
+DROP FUNCTION pg_catalog.worker_fix_partition_shard_index_names(regclass, text, text);

src/backend/distributed/sql/udfs/fix_all_partition_shard_index_names/10.2-4.sql

@@ -0,0 +1,21 @@
+CREATE OR REPLACE FUNCTION pg_catalog.fix_all_partition_shard_index_names()
+  RETURNS SETOF regclass
+  LANGUAGE plpgsql
+  AS $$
+DECLARE
+	dist_partitioned_table_name regclass;
+BEGIN
+  FOR dist_partitioned_table_name IN SELECT p.logicalrelid
+                                     FROM pg_dist_partition p
+                                     JOIN pg_class c ON p.logicalrelid = c.oid
+                                     WHERE c.relkind = 'p'
+		                                 ORDER BY c.relname, c.oid
+    LOOP
+      EXECUTE 'SELECT fix_partition_shard_index_names( ' || quote_literal(dist_partitioned_table_name) || ' )';
+      RETURN NEXT dist_partitioned_table_name;
+    END LOOP;
+  RETURN;
+END;
+$$;
+COMMENT ON FUNCTION pg_catalog.fix_all_partition_shard_index_names()
+  IS 'fix index names on partition shards of all tables';

src/backend/distributed/sql/udfs/fix_partition_shard_index_names/10.2-4.sql

@@ -0,0 +1,6 @@
+CREATE FUNCTION pg_catalog.fix_partition_shard_index_names(table_name regclass)
+  RETURNS void
+  LANGUAGE C STRICT
+  AS 'MODULE_PATHNAME', $$fix_partition_shard_index_names$$;
+COMMENT ON FUNCTION pg_catalog.fix_partition_shard_index_names(table_name regclass)
+  IS 'fix index names on partition shards of given table';

src/backend/distributed/sql/udfs/worker_fix_partition_shard_index_names/10.2-4.sql

@@ -0,0 +1,10 @@
+CREATE FUNCTION pg_catalog.worker_fix_partition_shard_index_names(parent_shard_index regclass,
+                                                                  partition_shard text,
+                                                                  new_partition_shard_index_name text)
+  RETURNS void
+  LANGUAGE C STRICT
+  AS 'MODULE_PATHNAME', $$worker_fix_partition_shard_index_names$$;
+COMMENT ON FUNCTION pg_catalog.worker_fix_partition_shard_index_names(parent_shard_index regclass,
+                                                                      partition_shard text,
+                                                                      new_partition_shard_index_name text)
+  IS 'fix the name of the index on given partition shard that is child of given parent_index';

src/test/regress/expected/multi_extension.out

@@ -864,6 +864,41 @@ SELECT * FROM multi_extension.print_extension_changes();
 ---------------------------------------------------------------------
 (0 rows)
 
+-- Test downgrade to 10.2-2 from 10.2-3
+ALTER EXTENSION citus UPDATE TO '10.2-3';
+ALTER EXTENSION citus UPDATE TO '10.2-2';
+-- Should be empty result since upgrade+downgrade should be a no-op
+SELECT * FROM multi_extension.print_extension_changes();
+ previous_object | current_object
+---------------------------------------------------------------------
+(0 rows)
+
+-- Snapshot of state at 10.2-3
+ALTER EXTENSION citus UPDATE TO '10.2-3';
+SELECT * FROM multi_extension.print_extension_changes();
+ previous_object | current_object
+---------------------------------------------------------------------
+(0 rows)
+
+-- Test downgrade to 10.2-3 from 10.2-4
+ALTER EXTENSION citus UPDATE TO '10.2-4';
+ALTER EXTENSION citus UPDATE TO '10.2-3';
+-- Should be empty result since upgrade+downgrade should be a no-op
+SELECT * FROM multi_extension.print_extension_changes();
+ previous_object | current_object
+---------------------------------------------------------------------
+(0 rows)
+
+-- Snapshot of state at 10.2-4
+ALTER EXTENSION citus UPDATE TO '10.2-4';
+SELECT * FROM multi_extension.print_extension_changes();
+ previous_object |                              current_object
+---------------------------------------------------------------------
+                 | function fix_all_partition_shard_index_names() SETOF regclass
+                 | function fix_partition_shard_index_names(regclass) void
+                 | function worker_fix_partition_shard_index_names(regclass,text,text) void
+(3 rows)
+
 DROP TABLE multi_extension.prev_objects, multi_extension.extension_diff;
 -- show running version
 SHOW citus.version;

src/test/regress/sql/multi_extension.sql

@@ -356,6 +356,26 @@ SELECT * FROM multi_extension.print_extension_changes();
 ALTER EXTENSION citus UPDATE TO '10.2-2';
 SELECT * FROM multi_extension.print_extension_changes();
 
+-- Test downgrade to 10.2-2 from 10.2-3
+ALTER EXTENSION citus UPDATE TO '10.2-3';
+ALTER EXTENSION citus UPDATE TO '10.2-2';
+-- Should be empty result since upgrade+downgrade should be a no-op
+SELECT * FROM multi_extension.print_extension_changes();
+
+-- Snapshot of state at 10.2-3
+ALTER EXTENSION citus UPDATE TO '10.2-3';
+SELECT * FROM multi_extension.print_extension_changes();
+
+-- Test downgrade to 10.2-3 from 10.2-4
+ALTER EXTENSION citus UPDATE TO '10.2-4';
+ALTER EXTENSION citus UPDATE TO '10.2-3';
+-- Should be empty result since upgrade+downgrade should be a no-op
+SELECT * FROM multi_extension.print_extension_changes();
+
+-- Snapshot of state at 10.2-4
+ALTER EXTENSION citus UPDATE TO '10.2-4';
+SELECT * FROM multi_extension.print_extension_changes();
+
 DROP TABLE multi_extension.prev_objects, multi_extension.extension_diff;
 
 -- show running version