20160725104020_merge_request_diff_remove_uniq.rb 1.11 KB
Newer Older
1 2 3
# See http://doc.gitlab.com/ce/development/migration_style_guide.html
# for more information on how to write migrations for GitLab.

4
# rubocop:disable RemoveIndex
5
class MergeRequestDiffRemoveUniq < ActiveRecord::Migration[4.2]
6 7 8 9 10 11
  include Gitlab::Database::MigrationHelpers
  disable_ddl_transaction!

  DOWNTIME = false

  def up
12 13 14 15 16 17 18 19 20 21 22 23
    constraint_name = 'merge_request_diffs_merge_request_id_key'

    transaction do
      if index_exists?(:merge_request_diffs, :merge_request_id)
        remove_index(:merge_request_diffs, :merge_request_id)
      end

      # In some bizarre cases PostgreSQL might have a separate unique constraint
      # that we'll need to drop.
      if constraint_exists?(constraint_name) && Gitlab::Database.postgresql?
        execute("ALTER TABLE merge_request_diffs DROP CONSTRAINT IF EXISTS #{constraint_name};")
      end
24 25 26 27 28
    end
  end

  def down
    unless index_exists?(:merge_request_diffs, :merge_request_id)
29
      add_concurrent_index(:merge_request_diffs, :merge_request_id, unique: true)
30 31
    end
  end
32 33 34 35

  def constraint_exists?(name)
    indexes(:merge_request_diffs).map(&:name).include?(name)
  end
36
end