debian-mirror-gitlab/db/migrate/20210201140434_add_oldest_merge_requests_index_again.rb
2021-03-11 19:13:27 +05:30

60 lines
1.6 KiB
Ruby

# frozen_string_literal: true
class AddOldestMergeRequestsIndexAgain < ActiveRecord::Migration[6.0]
include Gitlab::Database::SchemaHelpers
include Gitlab::Database::MigrationHelpers
disable_ddl_transaction!
DOWNTIME = false
INDEX = 'index_on_merge_requests_for_latest_diffs'
def up
execute "DROP INDEX CONCURRENTLY #{INDEX}" if invalid_index?
return if index_exists_by_name?('merge_requests', INDEX)
begin
disable_statement_timeout do
execute "CREATE INDEX CONCURRENTLY #{INDEX} ON merge_requests " \
'USING btree (target_project_id) INCLUDE (id, latest_merge_request_diff_id)'
end
rescue ActiveRecord::StatementInvalid => ex
# Due to https://github.com/lfittl/pg_query/issues/184, if the CREATE
# INDEX statement fails, we trigger a separate error due to the Gem not
# supporting the INCLUDE syntax.
#
# To work around this, we raise a custom error instead, as these won't
# have a query context injected.
raise "The index #{INDEX} couldn't be added: #{ex.message}"
end
create_comment(
'INDEX',
INDEX,
'Index used to efficiently obtain the oldest merge request for a commit SHA'
)
end
def down
return unless index_exists_by_name?('merge_requests', INDEX)
disable_statement_timeout do
execute "DROP INDEX CONCURRENTLY #{INDEX}"
end
end
def invalid_index?
result = execute(<<~SQL)
SELECT pg_class.relname
FROM pg_class, pg_index
WHERE pg_index.indisvalid = false
AND pg_index.indexrelid = pg_class.oid
AND pg_class.relname = '#{INDEX}';
SQL
result.values.any?
end
end