Prepare loose FK table for sliding partitioning

db/migrate/20211118100959_change_default_value_of_loose_fk_deleted_records_partition.rb

+# frozen_string_literal: true
+
+class ChangeDefaultValueOfLooseFkDeletedRecordsPartition < Gitlab::Database::Migration[1.0]
+  enable_lock_retries!
+
+  def change
+    change_column_default(:loose_foreign_keys_deleted_records, :partition, from: nil, to: 1)
+  end
+end

db/migrate/20211118103439_remove_hardcoded_partition_from_loose_fk_trigger_function.rb

+# frozen_string_literal: true
+
+class RemoveHardcodedPartitionFromLooseFkTriggerFunction < Gitlab::Database::Migration[1.0]
+  include Gitlab::Database::MigrationHelpers::LooseForeignKeyHelpers
+
+  enable_lock_retries!
+
+  def up
+    execute(<<~SQL)
+      CREATE OR REPLACE FUNCTION #{DELETED_RECORDS_INSERT_FUNCTION_NAME}()
+      RETURNS TRIGGER AS
+      $$
+      BEGIN
+        INSERT INTO loose_foreign_keys_deleted_records
+        (fully_qualified_table_name, primary_key_value)
+        SELECT TG_TABLE_SCHEMA || '.' || TG_TABLE_NAME, old_table.id FROM old_table;
+
+        RETURN NULL;
+      END
+      $$ LANGUAGE PLPGSQL
+    SQL
+  end
+
+  def down
+    execute(<<~SQL)
+      CREATE OR REPLACE FUNCTION #{DELETED_RECORDS_INSERT_FUNCTION_NAME}()
+      RETURNS TRIGGER AS
+      $$
+      BEGIN
+        INSERT INTO loose_foreign_keys_deleted_records
+        (partition, fully_qualified_table_name, primary_key_value)
+        SELECT 1, TG_TABLE_SCHEMA || '.' || TG_TABLE_NAME, old_table.id FROM old_table
+        ON CONFLICT DO NOTHING;
+
+        RETURN NULL;
+      END
+      $$ LANGUAGE PLPGSQL
+    SQL
+  end
+end

db/schema_migrations/20211118100959

+8b1bb9758150151518f16307d3f145431000b7edf946fd44e54cf7301087b002
\ No newline at end of file

db/schema_migrations/20211118103439

+721f1ada9fe5a3d7e5da3750a43d5021a85a26e8adc4d649e7f0fff8cdf68344
\ No newline at end of file

db/structure.sql

@@ -27,9 +27,8 @@ CREATE FUNCTION insert_into_loose_foreign_keys_deleted_records() RETURNS trigger
     AS $$
 BEGIN
   INSERT INTO loose_foreign_keys_deleted_records
-  (partition, fully_qualified_table_name, primary_key_value)
-  SELECT 1, TG_TABLE_SCHEMA || '.' || TG_TABLE_NAME, old_table.id FROM old_table
-  ON CONFLICT DO NOTHING;
+  (fully_qualified_table_name, primary_key_value)
+  SELECT TG_TABLE_SCHEMA || '.' || TG_TABLE_NAME, old_table.id FROM old_table;
 
   RETURN NULL;
 END
@@ -1016,7 +1015,7 @@ ALTER TABLE ONLY analytics_cycle_analytics_merge_request_stage_events ATTACH PAR
 
 CREATE TABLE loose_foreign_keys_deleted_records (
     id bigint NOT NULL,
-    partition bigint NOT NULL,
+    partition bigint DEFAULT 1 NOT NULL,
     primary_key_value bigint NOT NULL,
     status smallint DEFAULT 1 NOT NULL,
     created_at timestamp with time zone DEFAULT now() NOT NULL,
@@ -1037,7 +1036,7 @@ ALTER SEQUENCE loose_foreign_keys_deleted_records_id_seq OWNED BY loose_foreign_
 
 CREATE TABLE gitlab_partitions_static.loose_foreign_keys_deleted_records_1 (
     id bigint DEFAULT nextval('loose_foreign_keys_deleted_records_id_seq'::regclass) NOT NULL,
-    partition bigint NOT NULL,
+    partition bigint DEFAULT 1 NOT NULL,
     primary_key_value bigint NOT NULL,
     status smallint DEFAULT 1 NOT NULL,
     created_at timestamp with time zone DEFAULT now() NOT NULL,