1 files changed, 48 insertions, 0 deletions
diff --git a/db/post_migrate/20170830150306_drop_events_for_migration_table.rb b/db/post_migrate/20170830150306_drop_events_for_migration_table.rb
new file mode 100644
index 00000000000..763ee9a810d
--- /dev/null
+++ b/db/post_migrate/20170830150306_drop_events_for_migration_table.rb
@@ -0,0 +1,48 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class DropEventsForMigrationTable < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  class Event < ActiveRecord::Base
+    include EachBatch
+  end
+
+  def up
+    transaction do
+      drop_table :events_for_migration
+    end
+  end
+
+  # rubocop: disable Migration/Datetime
+  def down
+    create_table :events_for_migration do |t|
+      t.string :target_type, index: true
+      t.integer :target_id, index: true
+      t.string :title
+      t.text :data
+      t.integer :project_id
+      t.datetime :created_at, index: true
+      t.datetime :updated_at
+      t.integer :action, index: true
+      t.integer :author_id, index: true
+
+      t.index [:project_id, :id]
+    end
+
+    Event.all.each_batch do |relation|
+      start_id, stop_id = relation.pluck('MIN(id), MAX(id)').first
+
+      execute <<-EOF.strip_heredoc
+      INSERT INTO events_for_migration (target_type, target_id, project_id, created_at, updated_at, action, author_id)
+      SELECT target_type, target_id, project_id, created_at, updated_at, action, author_id
+      FROM events
+      WHERE id BETWEEN #{start_id} AND #{stop_id}
+      EOF
+    end
+  end
+end