Address the PK Overflow risk for the ci_build_needs - Step 3

- Remove build_id_convert_to_bigint column
- Remove trigger_21e7a2602957 trigger

Related to https://gitlab.com/gitlab-org/gitlab/-/issues/338060

Changelog: added

db/post_migrate/20210902144144_drop_temporary_columns_and_triggers_for_ci_build_needs.rb

+# frozen_string_literal: true
+
+class DropTemporaryColumnsAndTriggersForCiBuildNeeds < Gitlab::Database::Migration[1.0]
+  disable_ddl_transaction!
+
+  TABLE = 'ci_build_needs'
+  TEMPORARY_COLUMN = 'build_id_convert_to_bigint'
+  MAIN_COLUMN = 'build_id'
+
+  # rubocop:disable Migration/WithLockRetriesDisallowedMethod
+  def up
+    with_lock_retries do
+      cleanup_conversion_of_integer_to_bigint(TABLE, MAIN_COLUMN)
+    end
+  end
+
+  def down
+    check_trigger_permissions!(TABLE)
+
+    with_lock_retries do
+      add_column(TABLE, TEMPORARY_COLUMN, :int, default: 0, null: false)
+      install_rename_triggers(TABLE, MAIN_COLUMN, TEMPORARY_COLUMN)
+    end
+  end
+  # rubocop:enable Migration/WithLockRetriesDisallowedMethod
+end

db/schema_migrations/20210902144144

+c99df310082dd6f5faff3cfd90dfca88af26d840889910ebac0e73ba483a09b2
\ No newline at end of file

db/structure.sql

@@ -52,15 +52,6 @@ RETURN NULL;
 END
 $$;
 
-CREATE FUNCTION trigger_21e7a2602957() RETURNS trigger
-    LANGUAGE plpgsql
-    AS $$
-BEGIN
-  NEW."build_id_convert_to_bigint" := NEW."build_id";
-  RETURN NEW;
-END;
-$$;
-
 CREATE FUNCTION trigger_3f6129be01d2() RETURNS trigger
     LANGUAGE plpgsql
     AS $$
@@ -11224,7 +11215,6 @@ ALTER SEQUENCE chat_teams_id_seq OWNED BY chat_teams.id;
 
 CREATE TABLE ci_build_needs (
     id integer NOT NULL,
-    build_id_convert_to_bigint integer DEFAULT 0 NOT NULL,
     name text NOT NULL,
     artifacts boolean DEFAULT true NOT NULL,
     optional boolean DEFAULT false NOT NULL,
@@ -27285,8 +27275,6 @@ ALTER INDEX product_analytics_events_experimental_pkey ATTACH PARTITION gitlab_p
 
 ALTER INDEX product_analytics_events_experimental_pkey ATTACH PARTITION gitlab_partitions_static.product_analytics_events_experimental_63_pkey;
 
-CREATE TRIGGER trigger_21e7a2602957 BEFORE INSERT OR UPDATE ON ci_build_needs FOR EACH ROW EXECUTE FUNCTION trigger_21e7a2602957();
-
 CREATE TRIGGER trigger_3f6129be01d2 BEFORE INSERT OR UPDATE ON ci_builds FOR EACH ROW EXECUTE FUNCTION trigger_3f6129be01d2();
 
 CREATE TRIGGER trigger_542d6c2ad72e BEFORE INSERT OR UPDATE ON ci_builds_metadata FOR EACH ROW EXECUTE FUNCTION trigger_542d6c2ad72e();

spec/migrations/20210902144144_drop_temporary_columns_and_triggers_for_ci_build_needs_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+require_migration!('drop_temporary_columns_and_triggers_for_ci_build_needs')
+
+RSpec.describe DropTemporaryColumnsAndTriggersForCiBuildNeeds do
+  let(:ci_build_needs_table) { table(:ci_build_needs) }
+
+  it 'correctly migrates up and down' do
+    reversible_migration do |migration|
+      migration.before -> {
+        expect(ci_build_needs_table.column_names).to include('build_id_convert_to_bigint')
+      }
+
+      migration.after -> {
+        ci_build_needs_table.reset_column_information
+        expect(ci_build_needs_table.column_names).not_to include('build_id_convert_to_bigint')
+      }
+    end
+  end
+end