Drop unused index on merge_requests table
What does this MR do?
9d8ebcfc introduced a temporary index on merge_requests
, which this MR drops again.
This came up during gitlab-com/gl-infra/production#2424 (comment 381214360), though it wasn't the actual cause (it just happened to surface the problem described in #229852 (comment 381380624)).
I also checked the index isn't being actively used on the GitLab.com primary and replicas.
Does this MR meet the acceptance criteria?
Conformity
Edited by Andreas Brandl