debian-mirror-gitlab/lib/gitlab/database/migrations/observers/query_statistics.rb
2021-04-17 20:07:23 +05:30

38 lines
1.1 KiB
Ruby

# frozen_string_literal: true
module Gitlab
module Database
module Migrations
module Observers
# This observer gathers statistics from the pg_stat_statements extension.
# Notice that this extension is not installed by default. In case it cannot
# be found, the observer does nothing and doesn't throw an error.
class QueryStatistics < MigrationObserver
include Gitlab::Database::SchemaHelpers
def before
return unless enabled?
connection.execute('select pg_stat_statements_reset()')
end
def record(observation)
return unless enabled?
observation.query_statistics = connection.execute(<<~SQL)
SELECT query, calls, total_time, max_time, mean_time, rows
FROM pg_stat_statements
ORDER BY total_time DESC
SQL
end
private
def enabled?
function_exists?(:pg_stat_statements_reset) && connection.view_exists?(:pg_stat_statements)
end
end
end
end
end
end