Remove unnecessary queries on Merge Request Metrics population scheduler
What does this MR do?
Are there points in the code the reviewer needs to double check?
Each iteration on each_batch was taking about ~20 seconds on 20171128214150_schedule_populate_merge_request_metrics_with_events_data.rb. Good thing is, the PopulateMergeRequestMetricsWithEventsData code already handles the filtering well in a sense we can basically delete the external queries on the post migration scheduler.
Why was this MR needed?
Migration taking too much time to run on staging gitlab-org/release/tasks#13 (closed).
Edited by Oswaldo Ferreira