Add support for DAG

This implements the support for `needs:` keyword
as part of GitLab CI. That makes some of the jobs
to be run out of order.

1 files changed, 20 insertions, 0 deletions

diff --git a/db/migrate/20190731084415_add_build_need.rb b/db/migrate/20190731084415_add_build_need.rb
new file mode 100644
index 00000000000..45b8abb480d
--- /dev/null
+++ b/db/migrate/20190731084415_add_build_need.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class AddBuildNeed < ActiveRecord::Migration[5.2]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def change
+    create_table :ci_build_needs, id: :serial do |t|
+      t.integer :build_id, null: false
+      t.text :name, null: false
+
+      t.index [:build_id, :name], unique: true
+      t.foreign_key :ci_builds, column: :build_id, on_delete: :cascade
+    end
+  end
+end