Add scheduled_at column to ci_builds, and add a partial index as well

db/migrate/20180913102839_create_build_schedules.rb

-# frozen_string_literal: true
-
-class CreateBuildSchedules < ActiveRecord::Migration
-  include Gitlab::Database::MigrationHelpers
-
-  DOWNTIME = false
-
-  disable_ddl_transaction!
-
-  def change
-    create_table :ci_build_schedules, id: :bigserial do |t|
-      t.integer :build_id, null: false
-      t.datetime :execute_at, null: false
-
-      t.foreign_key :ci_builds, column: :build_id, on_delete: :cascade
-      t.index :build_id, unique: true
-    end
-  end
-end

db/migrate/20180924190739_add_scheduled_at_to_ci_builds.rb

+# frozen_string_literal: true
+
+class AddScheduledAtToCiBuilds < ActiveRecord::Migration
+  DOWNTIME = false
+
+  def change
+    add_column :ci_builds, :scheduled_at, :datetime_with_timezone
+  end
+end

db/migrate/20180924201039_add_partial_index_to_scheduled_at.rb

+# frozen_string_literal: true
+
+class AddPartialIndexToScheduledAt < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  INDEX_NAME = 'partial_index_ci_builds_on_id_with_scheduled_jobs'.freeze
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index(:ci_builds, :id, where: "scheduled_at <> NULL", name: INDEX_NAME)
+  end
+
+  def down
+    remove_concurrent_index_by_name(:ci_builds, INDEX_NAME)
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20180924141949) do
+ActiveRecord::Schema.define(version: 20180924201039) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -341,6 +341,7 @@ ActiveRecord::Schema.define(version: 20180924141949) do
     t.integer "artifacts_metadata_store"
     t.boolean "protected"
     t.integer "failure_reason"
+    t.datetime_with_timezone "scheduled_at"
   end
 
   add_index "ci_builds", ["artifacts_expire_at"], name: "index_ci_builds_on_artifacts_expire_at", where: "(artifacts_file <> ''::text)", using: :btree
@@ -350,6 +351,7 @@ ActiveRecord::Schema.define(version: 20180924141949) do
   add_index "ci_builds", ["commit_id", "type", "name", "ref"], name: "index_ci_builds_on_commit_id_and_type_and_name_and_ref", using: :btree
   add_index "ci_builds", ["commit_id", "type", "ref"], name: "index_ci_builds_on_commit_id_and_type_and_ref", using: :btree
   add_index "ci_builds", ["id"], name: "partial_index_ci_builds_on_id_with_legacy_artifacts", where: "(artifacts_file <> ''::text)", using: :btree
+  add_index "ci_builds", ["id"], name: "partial_index_ci_builds_on_id_with_scheduled_jobs", where: "(scheduled_at <> NULL::timestamp with time zone)", using: :btree
   add_index "ci_builds", ["project_id", "id"], name: "index_ci_builds_on_project_id_and_id", using: :btree
   add_index "ci_builds", ["protected"], name: "index_ci_builds_on_protected", using: :btree
   add_index "ci_builds", ["runner_id"], name: "index_ci_builds_on_runner_id", using: :btree
@@ -1799,6 +1801,7 @@ ActiveRecord::Schema.define(version: 20180924141949) do
   end
 
   add_index "redirect_routes", ["path"], name: "index_redirect_routes_on_path", unique: true, using: :btree
+  add_index "redirect_routes", ["path"], name: "index_redirect_routes_on_path_text_pattern_ops", using: :btree, opclasses: {"path"=>"varchar_pattern_ops"}
   add_index "redirect_routes", ["source_type", "source_id"], name: "index_redirect_routes_on_source_type_and_source_id", using: :btree
 
   create_table "releases", force: :cascade do |t|