Create partial indexes for pending/running builds

Changelog: performance

changelogs/unreleased/ab-ci-builds-partial-indexes.yml

+---
+title: Create partial indexes for pending/running builds
+merge_request: 60942
+author:
+type: performance

db/migrate/20210504164429_create_partial_indexes_for_pending_and_running_builds.rb

+# frozen_string_literal: true
+
+class CreatePartialIndexesForPendingAndRunningBuilds < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  disable_ddl_transaction!
+
+  INDEX_PENDING = 'index_ci_builds_runner_id_pending'
+  INDEX_RUNNING = 'index_ci_builds_runner_id_running'
+
+  def up
+    add_concurrent_index :ci_builds, :runner_id, where: "status = 'pending' AND type = 'Ci::Build'", name: INDEX_PENDING
+    add_concurrent_index :ci_builds, :runner_id, where: "status = 'running' AND type = 'Ci::Build'", name: INDEX_RUNNING
+  end
+
+  def down
+    remove_concurrent_index_by_name :ci_builds, INDEX_PENDING
+    remove_concurrent_index_by_name :ci_builds, INDEX_RUNNING
+  end
+end

db/schema_migrations/20210504164429

+767cea885e6544b6958082397812357d7223b193d4b73bf09c8486dc2ec645d0
\ No newline at end of file

db/structure.sql

@@ -22368,6 +22368,10 @@ CREATE INDEX index_ci_builds_on_user_id_and_created_at_and_type_eq_ci_build ON c
 
 CREATE INDEX index_ci_builds_project_id_and_status_for_live_jobs_partial2 ON ci_builds USING btree (project_id, status) WHERE (((type)::text = 'Ci::Build'::text) AND ((status)::text = ANY (ARRAY[('running'::character varying)::text, ('pending'::character varying)::text, ('created'::character varying)::text])));
 
+CREATE INDEX index_ci_builds_runner_id_pending ON ci_builds USING btree (runner_id) WHERE (((status)::text = 'pending'::text) AND ((type)::text = 'Ci::Build'::text));
+
+CREATE INDEX index_ci_builds_runner_id_running ON ci_builds USING btree (runner_id) WHERE (((status)::text = 'running'::text) AND ((type)::text = 'Ci::Build'::text));
+
 CREATE UNIQUE INDEX index_ci_builds_runner_session_on_build_id ON ci_builds_runner_session USING btree (build_id);
 
 CREATE INDEX index_ci_daily_build_group_report_results_on_group_id ON ci_daily_build_group_report_results USING btree (group_id);