44 lines
1.4 KiB
Ruby
44 lines
1.4 KiB
Ruby
# frozen_string_literal: true
|
|
|
|
class RemoveOrphanedLabelLinks < ActiveRecord::Migration[4.2]
|
|
include Gitlab::Database::MigrationHelpers
|
|
|
|
DOWNTIME = false
|
|
|
|
disable_ddl_transaction!
|
|
|
|
class LabelLinks < ActiveRecord::Base
|
|
self.table_name = 'label_links'
|
|
include EachBatch
|
|
|
|
def self.orphaned
|
|
where('NOT EXISTS ( SELECT 1 FROM labels WHERE labels.id = label_links.label_id )')
|
|
end
|
|
end
|
|
|
|
def up
|
|
# Some of these queries can take up to 10 seconds to run on GitLab.com,
|
|
# which is pretty close to our 15 second statement timeout. To ensure a
|
|
# smooth deployment procedure we disable the statement timeouts for this
|
|
# migration, just in case.
|
|
disable_statement_timeout do
|
|
# On GitLab.com there are over 2,000,000 orphaned label links. On
|
|
# staging, removing 100,000 rows generated a max replication lag of 6.7
|
|
# MB. In total, removing all these rows will only generate about 136 MB
|
|
# of data, so it should be safe to do this.
|
|
LabelLinks.orphaned.each_batch(of: 100_000) do |batch|
|
|
batch.delete_all
|
|
end
|
|
end
|
|
|
|
add_concurrent_foreign_key(:label_links, :labels, column: :label_id, on_delete: :cascade)
|
|
end
|
|
|
|
def down
|
|
# There is no way to restore orphaned label links.
|
|
if foreign_key_exists?(:label_links, column: :label_id)
|
|
remove_foreign_key(:label_links, column: :label_id)
|
|
end
|
|
end
|
|
end
|