Remove pg_depend entries from columnar metadata indexes to columnar-am

In the past, having columnar tables in the cluster was causing pg
upgrades to fail when attempting to access columnar metadata. This is
because, pg_dump doesn't see objects that we use for columnar-am related
booking as the dependencies of the tables using columnar-am.
To fix that; in #5456, we inserted some "normal dependency" edges (from
those objects to columnar-am) into pg_depend.

This helped us ensuring the existency of a class of metadata objects
--such as columnar.storageid_seq-- and helped fixing #5437.

However, the normal-dependency edges that we added for indexes on
columnar metadata tables --such columnar.stripe_pkey-- didn't help at
all because they were indeed causing dependency loops (#5510) and
pg_dump was not able to take those dependency edges into the account.

For this reason, this commit deletes those dependency edges so that
pg_dump stops complaining about them. Note that it's not critical to
delete those edges from pg_depend since they're not breaking pg upgrades
but were triggering some warning messages. And given that backporting
a sql change into older versions is hard a lot, we skip backporting
this.

src/backend/columnar/sql/citus_columnar--11.1-1--11.2-1.sql

@@ -1 +1,19 @@
 -- citus_columnar--11.1-1--11.2-1
+
+#include "udfs/columnar_ensure_am_depends_catalog/11.2-1.sql"
+
+DELETE FROM pg_depend
+WHERE classid = 'pg_am'::regclass::oid
+    AND objid IN (select oid from pg_am where amname = 'columnar')
+    AND objsubid = 0
+    AND refclassid = 'pg_class'::regclass::oid
+    AND refobjid IN (
+        'columnar_internal.stripe_first_row_number_idx'::regclass::oid,
+        'columnar_internal.chunk_group_pkey'::regclass::oid,
+        'columnar_internal.chunk_pkey'::regclass::oid,
+        'columnar_internal.options_pkey'::regclass::oid,
+        'columnar_internal.stripe_first_row_number_idx'::regclass::oid,
+        'columnar_internal.stripe_pkey'::regclass::oid
+    )
+    AND refobjsubid = 0
+    AND deptype = 'n';

src/backend/columnar/sql/downgrades/citus_columnar--11.2-1--11.1-1.sql

@@ -1 +1,4 @@
 -- citus_columnar--11.2-1--11.1-1
+
+-- Note that we intentionally do not re-insert the pg_depend records that we
+-- deleted via citus_columnar--11.1-1--11.2-1.sql.

src/backend/columnar/sql/udfs/columnar_ensure_am_depends_catalog/11.2-1.sql

@@ -0,0 +1,43 @@
+CREATE OR REPLACE FUNCTION columnar_internal.columnar_ensure_am_depends_catalog()
+  RETURNS void
+  LANGUAGE plpgsql
+  SET search_path = pg_catalog
+AS $func$
+BEGIN
+  INSERT INTO pg_depend
+  WITH columnar_schema_members(relid) AS (
+    SELECT pg_class.oid AS relid FROM pg_class
+      WHERE relnamespace =
+            COALESCE(
+	       (SELECT pg_namespace.oid FROM pg_namespace WHERE nspname = 'columnar_internal'),
+	       (SELECT pg_namespace.oid FROM pg_namespace WHERE nspname = 'columnar')
+	    )
+        AND relname IN ('chunk',
+                        'chunk_group',
+                        'options',
+                        'storageid_seq',
+                        'stripe')
+  )
+  SELECT -- Define a dependency edge from "columnar table access method" ..
+         'pg_am'::regclass::oid as classid,
+         (select oid from pg_am where amname = 'columnar') as objid,
+         0 as objsubid,
+         -- ... to some objects registered as regclass and that lives in
+         -- "columnar" schema. That contains catalog tables and the sequences
+         -- created in "columnar" schema.
+         --
+         -- Given the possibility of user might have created their own objects
+         -- in columnar schema, we explicitly specify list of objects that we
+         -- are interested in.
+         'pg_class'::regclass::oid as refclassid,
+         columnar_schema_members.relid as refobjid,
+         0 as refobjsubid,
+         'n' as deptype
+  FROM columnar_schema_members
+  -- Avoid inserting duplicate entries into pg_depend.
+  EXCEPT TABLE pg_depend;
+END;
+$func$;
+COMMENT ON FUNCTION columnar_internal.columnar_ensure_am_depends_catalog()
+  IS 'internal function responsible for creating dependencies from columnar '
+     'table access method to the rel objects in columnar schema';

src/backend/columnar/sql/udfs/columnar_ensure_am_depends_catalog/latest.sql

@@ -1,4 +1,4 @@
-CREATE OR REPLACE FUNCTION citus_internal.columnar_ensure_am_depends_catalog()
+CREATE OR REPLACE FUNCTION columnar_internal.columnar_ensure_am_depends_catalog()
   RETURNS void
   LANGUAGE plpgsql
   SET search_path = pg_catalog
@@ -14,22 +14,17 @@ BEGIN
 	    )
         AND relname IN ('chunk',
                         'chunk_group',
-                        'chunk_group_pkey',
-                        'chunk_pkey',
                         'options',
-                        'options_pkey',
                         'storageid_seq',
-                        'stripe',
+                        'stripe')
-                        'stripe_first_row_number_idx',
-                        'stripe_pkey')
   )
   SELECT -- Define a dependency edge from "columnar table access method" ..
          'pg_am'::regclass::oid as classid,
          (select oid from pg_am where amname = 'columnar') as objid,
          0 as objsubid,
-         -- ... to each object that is registered to pg_class and that lives
+         -- ... to some objects registered as regclass and that lives in
-         -- in "columnar" schema. That contains catalog tables, indexes
+         -- "columnar" schema. That contains catalog tables and the sequences
-         -- created on them and the sequences created in "columnar" schema.
+         -- created in "columnar" schema.
          --
          -- Given the possibility of user might have created their own objects
          -- in columnar schema, we explicitly specify list of objects that we
@@ -43,6 +38,6 @@ BEGIN
   EXCEPT TABLE pg_depend;
 END;
 $func$;
-COMMENT ON FUNCTION citus_internal.columnar_ensure_am_depends_catalog()
+COMMENT ON FUNCTION columnar_internal.columnar_ensure_am_depends_catalog()
   IS 'internal function responsible for creating dependencies from columnar '
      'table access method to the rel objects in columnar schema';

src/test/regress/expected/multi_extension.out

@@ -1258,6 +1258,43 @@ SELECT * FROM pg_dist_cleanup;
          2 |            0 |           1 | table_with_orphaned_shards_102011 |             0 |           0
 (2 rows)
 
+ALTER EXTENSION citus_columnar UPDATE TO '11.2-1';
+-- Make sure that we defined dependencies from all rel objects (tables,
+-- indexes, sequences ..) to columnar table access method ...
+SELECT pg_class.oid INTO columnar_schema_members
+FROM pg_class, pg_namespace
+WHERE pg_namespace.oid=pg_class.relnamespace AND
+      pg_namespace.nspname='columnar_internal' AND
+      pg_class.relname NOT IN ('chunk_group_pkey',
+                               'chunk_pkey',
+                               'options_pkey',
+                               'stripe_first_row_number_idx',
+                               'stripe_pkey');
+SELECT refobjid INTO columnar_schema_members_pg_depend
+FROM pg_depend
+WHERE classid = 'pg_am'::regclass::oid AND
+      objid = (select oid from pg_am where amname = 'columnar') AND
+      objsubid = 0 AND
+      refclassid = 'pg_class'::regclass::oid AND
+      refobjsubid = 0 AND
+      deptype = 'n';
+-- ... , so this should be empty,
+(TABLE columnar_schema_members EXCEPT TABLE columnar_schema_members_pg_depend)
+UNION
+(TABLE columnar_schema_members_pg_depend EXCEPT TABLE columnar_schema_members);
+ oid
+---------------------------------------------------------------------
+(0 rows)
+
+-- ... , and both columnar_schema_members_pg_depend & columnar_schema_members
+-- should have 5 entries.
+SELECT COUNT(*)=5 FROM columnar_schema_members_pg_depend;
+ ?column?
+---------------------------------------------------------------------
+ t
+(1 row)
+
+DROP TABLE columnar_schema_members, columnar_schema_members_pg_depend;
 -- error out as cleanup records remain
 ALTER EXTENSION citus UPDATE TO '11.0-4';
 ERROR:  pg_dist_cleanup is introduced in Citus 11.1

src/test/regress/expected/upgrade_columnar_after.out

@@ -267,7 +267,12 @@ ROLLBACK;
 SELECT pg_class.oid INTO columnar_schema_members
 FROM pg_class, pg_namespace
 WHERE pg_namespace.oid=pg_class.relnamespace AND
-      pg_namespace.nspname='columnar_internal';
+      pg_namespace.nspname='columnar_internal' AND
+      pg_class.relname NOT IN ('chunk_group_pkey',
+                               'chunk_pkey',
+                               'options_pkey',
+                               'stripe_first_row_number_idx',
+                               'stripe_pkey');
 SELECT refobjid INTO columnar_schema_members_pg_depend
 FROM pg_depend
 WHERE classid = 'pg_am'::regclass::oid AND
@@ -285,8 +290,8 @@ UNION
 (0 rows)
 
 -- ... , and both columnar_schema_members_pg_depend & columnar_schema_members
--- should have 10 entries.
+-- should have 5 entries.
-SELECT COUNT(*)=10 FROM columnar_schema_members_pg_depend;
+SELECT COUNT(*)=5 FROM columnar_schema_members_pg_depend;
  ?column?
 ---------------------------------------------------------------------
  t
@@ -299,7 +304,12 @@ $$
 SELECT pg_class.oid INTO columnar_schema_members
 FROM pg_class, pg_namespace
 WHERE pg_namespace.oid=pg_class.relnamespace AND
-	  pg_namespace.nspname='columnar_internal';
+      pg_namespace.nspname='columnar_internal' AND
+      pg_class.relname NOT IN ('chunk_group_pkey',
+                               'chunk_pkey',
+                               'options_pkey',
+                               'stripe_first_row_number_idx',
+                               'stripe_pkey');
 SELECT refobjid INTO columnar_schema_members_pg_depend
 FROM pg_depend
 WHERE classid = 'pg_am'::regclass::oid AND
@@ -312,8 +322,8 @@ $$
 );
  success |  result
 ---------------------------------------------------------------------
- t       | SELECT 10
+ t       | SELECT 5
- t       | SELECT 10
+ t       | SELECT 5
 (2 rows)
 
 SELECT success, result FROM run_command_on_workers(
@@ -331,7 +341,7 @@ $$
 
 SELECT success, result FROM run_command_on_workers(
 $$
-SELECT COUNT(*)=10 FROM columnar_schema_members_pg_depend;
+SELECT COUNT(*)=5 FROM columnar_schema_members_pg_depend;
 $$
 );
  success | result

src/test/regress/sql/multi_extension.sql

@@ -556,6 +556,39 @@ ALTER EXTENSION citus UPDATE TO '11.2-1';
 SELECT * FROM pg_dist_placement ORDER BY shardid;
 SELECT * FROM pg_dist_cleanup;
 
+ALTER EXTENSION citus_columnar UPDATE TO '11.2-1';
+
+-- Make sure that we defined dependencies from all rel objects (tables,
+-- indexes, sequences ..) to columnar table access method ...
+SELECT pg_class.oid INTO columnar_schema_members
+FROM pg_class, pg_namespace
+WHERE pg_namespace.oid=pg_class.relnamespace AND
+      pg_namespace.nspname='columnar_internal' AND
+      pg_class.relname NOT IN ('chunk_group_pkey',
+                               'chunk_pkey',
+                               'options_pkey',
+                               'stripe_first_row_number_idx',
+                               'stripe_pkey');
+SELECT refobjid INTO columnar_schema_members_pg_depend
+FROM pg_depend
+WHERE classid = 'pg_am'::regclass::oid AND
+      objid = (select oid from pg_am where amname = 'columnar') AND
+      objsubid = 0 AND
+      refclassid = 'pg_class'::regclass::oid AND
+      refobjsubid = 0 AND
+      deptype = 'n';
+
+-- ... , so this should be empty,
+(TABLE columnar_schema_members EXCEPT TABLE columnar_schema_members_pg_depend)
+UNION
+(TABLE columnar_schema_members_pg_depend EXCEPT TABLE columnar_schema_members);
+
+-- ... , and both columnar_schema_members_pg_depend & columnar_schema_members
+-- should have 5 entries.
+SELECT COUNT(*)=5 FROM columnar_schema_members_pg_depend;
+
+DROP TABLE columnar_schema_members, columnar_schema_members_pg_depend;
+
 -- error out as cleanup records remain
 ALTER EXTENSION citus UPDATE TO '11.0-4';
 

src/test/regress/sql/upgrade_columnar_after.sql

@@ -139,7 +139,12 @@ ROLLBACK;
 SELECT pg_class.oid INTO columnar_schema_members
 FROM pg_class, pg_namespace
 WHERE pg_namespace.oid=pg_class.relnamespace AND
-      pg_namespace.nspname='columnar_internal';
+      pg_namespace.nspname='columnar_internal' AND
+      pg_class.relname NOT IN ('chunk_group_pkey',
+                               'chunk_pkey',
+                               'options_pkey',
+                               'stripe_first_row_number_idx',
+                               'stripe_pkey');
 SELECT refobjid INTO columnar_schema_members_pg_depend
 FROM pg_depend
 WHERE classid = 'pg_am'::regclass::oid AND
@@ -155,8 +160,8 @@ UNION
 (TABLE columnar_schema_members_pg_depend EXCEPT TABLE columnar_schema_members);
 
 -- ... , and both columnar_schema_members_pg_depend & columnar_schema_members
--- should have 10 entries.
+-- should have 5 entries.
-SELECT COUNT(*)=10 FROM columnar_schema_members_pg_depend;
+SELECT COUNT(*)=5 FROM columnar_schema_members_pg_depend;
 
 DROP TABLE columnar_schema_members, columnar_schema_members_pg_depend;
 
@@ -167,7 +172,12 @@ $$
 SELECT pg_class.oid INTO columnar_schema_members
 FROM pg_class, pg_namespace
 WHERE pg_namespace.oid=pg_class.relnamespace AND
-	  pg_namespace.nspname='columnar_internal';
+      pg_namespace.nspname='columnar_internal' AND
+      pg_class.relname NOT IN ('chunk_group_pkey',
+                               'chunk_pkey',
+                               'options_pkey',
+                               'stripe_first_row_number_idx',
+                               'stripe_pkey');
 SELECT refobjid INTO columnar_schema_members_pg_depend
 FROM pg_depend
 WHERE classid = 'pg_am'::regclass::oid AND
@@ -189,7 +199,7 @@ $$
 
 SELECT success, result FROM run_command_on_workers(
 $$
-SELECT COUNT(*)=10 FROM columnar_schema_members_pg_depend;
+SELECT COUNT(*)=5 FROM columnar_schema_members_pg_depend;
 $$
 );