Remove type column from audit_events table

This column is no longer needed as we have moved away from STI model and
it is currently under-utilized (i.e. only contains one type). The
prerequisite work to remove all write logic in application has been
deployed with previous release.

changelogs/unreleased/229727-drop-type-on-audit-events.yml

+---
+title: Remove type column on audit_events table
+merge_request: 43703
+author:
+type: other

db/post_migrate/20200929113254_remove_type_from_audit_events.rb

+# frozen_string_literal: true
+
+class RemoveTypeFromAuditEvents < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::SchemaHelpers
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  SOURCE_TABLE_NAME = 'audit_events'
+  PARTITIONED_TABLE_NAME = 'audit_events_part_5fc467ac26'
+  TRIGGER_FUNCTION_NAME = 'table_sync_function_2be879775d'
+
+  def up
+    with_lock_retries do
+      remove_column SOURCE_TABLE_NAME, :type
+
+      create_trigger_function(TRIGGER_FUNCTION_NAME, replace: true) do
+        <<~SQL
+          IF (TG_OP = 'DELETE') THEN
+            DELETE FROM #{PARTITIONED_TABLE_NAME} where id = OLD.id;
+          ELSIF (TG_OP = 'UPDATE') THEN
+            UPDATE #{PARTITIONED_TABLE_NAME}
+            SET author_id = NEW.author_id,
+              entity_id = NEW.entity_id,
+              entity_type = NEW.entity_type,
+              details = NEW.details,
+              ip_address = NEW.ip_address,
+              author_name = NEW.author_name,
+              entity_path = NEW.entity_path,
+              target_details = NEW.target_details,
+              target_type = NEW.target_type,
+              target_id = NEW.target_id,
+              created_at = NEW.created_at
+            WHERE #{PARTITIONED_TABLE_NAME}.id = NEW.id;
+          ELSIF (TG_OP = 'INSERT') THEN
+            INSERT INTO #{PARTITIONED_TABLE_NAME} (id,
+              author_id,
+              entity_id,
+              entity_type,
+              details,
+              ip_address,
+              author_name,
+              entity_path,
+              target_details,
+              target_type,
+              target_id,
+              created_at)
+            VALUES (NEW.id,
+              NEW.author_id,
+              NEW.entity_id,
+              NEW.entity_type,
+              NEW.details,
+              NEW.ip_address,
+              NEW.author_name,
+              NEW.entity_path,
+              NEW.target_details,
+              NEW.target_type,
+              NEW.target_id,
+              NEW.created_at);
+          END IF;
+          RETURN NULL;
+        SQL
+      end
+
+      remove_column PARTITIONED_TABLE_NAME, :type
+    end
+  end
+
+  def down
+    with_lock_retries do
+      add_column SOURCE_TABLE_NAME, :type, :string
+      add_column PARTITIONED_TABLE_NAME, :type, :string
+
+      create_trigger_function(TRIGGER_FUNCTION_NAME, replace: true) do
+        <<~SQL
+          IF (TG_OP = 'DELETE') THEN
+            DELETE FROM #{PARTITIONED_TABLE_NAME} where id = OLD.id;
+          ELSIF (TG_OP = 'UPDATE') THEN
+            UPDATE #{PARTITIONED_TABLE_NAME}
+            SET author_id = NEW.author_id,
+              type = NEW.type,
+              entity_id = NEW.entity_id,
+              entity_type = NEW.entity_type,
+              details = NEW.details,
+              ip_address = NEW.ip_address,
+              author_name = NEW.author_name,
+              entity_path = NEW.entity_path,
+              target_details = NEW.target_details,
+              target_type = NEW.target_type,
+              target_id = NEW.target_id,
+              created_at = NEW.created_at
+            WHERE #{PARTITIONED_TABLE_NAME}.id = NEW.id;
+          ELSIF (TG_OP = 'INSERT') THEN
+            INSERT INTO #{PARTITIONED_TABLE_NAME} (id,
+              author_id,
+              type,
+              entity_id,
+              entity_type,
+              details,
+              ip_address,
+              author_name,
+              entity_path,
+              target_details,
+              target_type,
+              target_id,
+              created_at)
+            VALUES (NEW.id,
+              NEW.author_id,
+              NEW.type,
+              NEW.entity_id,
+              NEW.entity_type,
+              NEW.details,
+              NEW.ip_address,
+              NEW.author_name,
+              NEW.entity_path,
+              NEW.target_details,
+              NEW.target_type,
+              NEW.target_id,
+              NEW.created_at);
+          END IF;
+          RETURN NULL;
+        SQL
+      end
+    end
+  end
+end

db/schema_migrations/20200929113254

+260f392c3ff257960dc7b198473056e7bf9b9a668403d2f05391d2b7989cf83c
\ No newline at end of file

db/structure.sql

@@ -19,7 +19,6 @@ IF (TG_OP = 'DELETE') THEN
 ELSIF (TG_OP = 'UPDATE') THEN
   UPDATE audit_events_part_5fc467ac26
   SET author_id = NEW.author_id,
-    type = NEW.type,
     entity_id = NEW.entity_id,
     entity_type = NEW.entity_type,
     details = NEW.details,
@@ -34,7 +33,6 @@ ELSIF (TG_OP = 'UPDATE') THEN
 ELSIF (TG_OP = 'INSERT') THEN
   INSERT INTO audit_events_part_5fc467ac26 (id,
     author_id,
-    type,
     entity_id,
     entity_type,
     details,
@@ -47,7 +45,6 @@ ELSIF (TG_OP = 'INSERT') THEN
     created_at)
   VALUES (NEW.id,
     NEW.author_id,
-    NEW.type,
     NEW.entity_id,
     NEW.entity_type,
     NEW.details,
@@ -69,7 +66,6 @@ COMMENT ON FUNCTION table_sync_function_2be879775d() IS 'Partitioning migration:
 CREATE TABLE audit_events_part_5fc467ac26 (
     id bigint NOT NULL,
     author_id integer NOT NULL,
-    type character varying,
     entity_id integer NOT NULL,
     entity_type character varying NOT NULL,
     details text,
@@ -9541,7 +9537,6 @@ ALTER SEQUENCE atlassian_identities_user_id_seq OWNED BY atlassian_identities.us
 CREATE TABLE audit_events (
     id integer NOT NULL,
     author_id integer NOT NULL,
-    type character varying,
     entity_id integer NOT NULL,
     entity_type character varying NOT NULL,
     details text,