Merge branch 'mk/part-1-enforce-not-null-external-diff-store-on-mr-diffs' into 'master'

Geo: Part 1 of Enforce not null merge_request_diffs.external_diff_store

See merge request gitlab-org/gitlab!38549

changelogs/unreleased/mk-part-1-enforce-not-null-external-diff-store-on-mr-diffs.yml

+---
+title: Add database migrations to prepare for future Geo replication
+merge_request: 38549
+author:
+type: changed

db/migrate/20200804041018_add_default_value_for_external_diff_store_to_merge_request_diffs.rb

+# frozen_string_literal: true
+
+class AddDefaultValueForExternalDiffStoreToMergeRequestDiffs < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def up
+    with_lock_retries do
+      change_column_default :merge_request_diffs, :external_diff_store, 1
+    end
+  end
+
+  def down
+    with_lock_retries do
+      change_column_default :merge_request_diffs, :external_diff_store, nil
+    end
+  end
+end

db/post_migrate/20200804035230_add_partial_index_on_id_to_merge_request_diffs.rb

+# frozen_string_literal: true
+
+class AddPartialIndexOnIdToMergeRequestDiffs < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  INDEX_NAME = 'index_merge_request_diffs_external_diff_store_is_null'
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :merge_request_diffs, :id, where: 'external_diff_store IS NULL', name: INDEX_NAME
+  end
+
+  def down
+    remove_concurrent_index_by_name :merge_request_diffs, INDEX_NAME
+  end
+end

db/post_migrate/20200804041930_add_not_null_constraint_on_external_diff_store_to_merge_request_diffs.rb

+# frozen_string_literal: true
+
+class AddNotNullConstraintOnExternalDiffStoreToMergeRequestDiffs < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_not_null_constraint(:merge_request_diffs, :external_diff_store, validate: false)
+  end
+
+  def down
+    remove_not_null_constraint(:merge_request_diffs, :external_diff_store)
+  end
+end

db/schema_migrations/20200804035230

+f1e2f11710ca7175b7a77b0f52bd204403dfcfd0b6b33cd00e3fa0d020be1287
\ No newline at end of file

db/schema_migrations/20200804041018

+ac65340525eba0cd025be706dde4deaf4574f8a7ffb9531d56ffae707e7e8b6d
\ No newline at end of file

db/schema_migrations/20200804041930

+3177e2f9549add35789e64b14c5958c4fb42fdce4b4705505bc9bbe326d9a875
\ No newline at end of file

db/structure.sql

@@ -13003,7 +13003,7 @@ CREATE TABLE public.merge_request_diffs (
     start_commit_sha character varying,
     commits_count integer,
     external_diff character varying,
-    external_diff_store integer,
+    external_diff_store integer DEFAULT 1,
     stored_externally boolean
 );
 
@@ -17614,6 +17614,9 @@ ALTER TABLE public.design_management_designs
 ALTER TABLE public.vulnerability_scanners
     ADD CONSTRAINT check_37608c9db5 CHECK ((char_length(vendor) <= 255)) NOT VALID;
 
+ALTER TABLE public.merge_request_diffs
+    ADD CONSTRAINT check_93ee616ac9 CHECK ((external_diff_store IS NOT NULL)) NOT VALID;
+
 ALTER TABLE ONLY public.ci_build_needs
     ADD CONSTRAINT ci_build_needs_pkey PRIMARY KEY (id);
 
@@ -19850,6 +19853,8 @@ CREATE INDEX index_merge_request_diff_commits_on_sha ON public.merge_request_dif
 
 CREATE UNIQUE INDEX index_merge_request_diff_files_on_mr_diff_id_and_order ON public.merge_request_diff_files USING btree (merge_request_diff_id, relative_order);
 
+CREATE INDEX index_merge_request_diffs_external_diff_store_is_null ON public.merge_request_diffs USING btree (id) WHERE (external_diff_store IS NULL);
+
 CREATE INDEX index_merge_request_diffs_on_external_diff_store ON public.merge_request_diffs USING btree (external_diff_store);
 
 CREATE INDEX index_merge_request_diffs_on_merge_request_id_and_id ON public.merge_request_diffs USING btree (merge_request_id, id);