Drop index `index_events_on_author_id_and_created_at_merge_requests` from events table
The events table has many indexes. We have found some, including index_events_on_author_id_and_created_at_merge_requests
, that are not used. This issue is to remove that index from the database.
UPDATE: index_events_on_author_id_and_created_at_merge_requests
is not completely un-used, but not used much - see pg_stat_user_indexes_idx_scan, and pg_stat_user_indexes_idx_tup_read
By reducing the number of indexes on that table, it will help to mitigate another issue (gitlab-com/gl-infra/scalability#2301 (closed))
We just did this for a different table and wrote down the process we followed here: #402497 (closed)
Edited by Thong Kuah