Add file store indexes

Especially because Geo is adding replication support for
these models. And by default, only locally stored files are
synced. Adding these indexes improves the performance of
the queries that determine what should be synced.

changelogs/unreleased/mk-add-file-store-indexes.yml

+---
+title: 'Geo: Add file store indexes'
+merge_request: 37265
+author:
+type: added

db/migrate/20200718040100_add_index_on_merge_request_diffs_external_diff_store.rb

+# frozen_string_literal: true
+
+class AddIndexOnMergeRequestDiffsExternalDiffStore < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :merge_request_diffs, :external_diff_store
+  end
+
+  def down
+    remove_concurrent_index :merge_request_diffs, :external_diff_store
+  end
+end

db/migrate/20200718040200_add_index_on_terraform_states_file_store.rb

+# frozen_string_literal: true
+
+class AddIndexOnTerraformStatesFileStore < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :terraform_states, :file_store
+  end
+
+  def down
+    remove_concurrent_index :terraform_states, :file_store
+  end
+end

db/migrate/20200718040300_add_index_on_vulnerability_exports_file_store.rb

+# frozen_string_literal: true
+
+class AddIndexOnVulnerabilityExportsFileStore < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :vulnerability_exports, :file_store
+  end
+
+  def down
+    remove_concurrent_index :vulnerability_exports, :file_store
+  end
+end

db/structure.sql

@@ -19717,6 +19717,8 @@ 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_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);
 
 CREATE INDEX index_merge_request_diffs_on_merge_request_id_and_id_partial ON public.merge_request_diffs USING btree (merge_request_id, id) WHERE ((NOT stored_externally) OR (stored_externally IS NULL));
@@ -20487,6 +20489,8 @@ CREATE INDEX index_term_agreements_on_term_id ON public.term_agreements USING bt
 
 CREATE INDEX index_term_agreements_on_user_id ON public.term_agreements USING btree (user_id);
 
+CREATE INDEX index_terraform_states_on_file_store ON public.terraform_states USING btree (file_store);
+
 CREATE INDEX index_terraform_states_on_locked_by_user_id ON public.terraform_states USING btree (locked_by_user_id);
 
 CREATE UNIQUE INDEX index_terraform_states_on_project_id_and_name ON public.terraform_states USING btree (project_id, name);
@@ -20645,6 +20649,8 @@ CREATE INDEX index_vulnerabilities_on_updated_by_id ON public.vulnerabilities US
 
 CREATE INDEX index_vulnerability_exports_on_author_id ON public.vulnerability_exports USING btree (author_id);
 
+CREATE INDEX index_vulnerability_exports_on_file_store ON public.vulnerability_exports USING btree (file_store);
+
 CREATE INDEX index_vulnerability_exports_on_group_id_not_null ON public.vulnerability_exports USING btree (group_id) WHERE (group_id IS NOT NULL);
 
 CREATE INDEX index_vulnerability_exports_on_project_id_not_null ON public.vulnerability_exports USING btree (project_id) WHERE (project_id IS NOT NULL);
@@ -23984,5 +23990,8 @@ COPY "schema_migrations" (version) FROM STDIN;
 20200715202659
 20200716044023
 20200716120419
+20200718040100
+20200718040200
+20200718040300
 \.