Update posgres heavy load
cc/ @jacobvosmaer-gitlab @northrup @jnijhof @eugene3 @maratkalibek
@yorickpeterse Is this query correct? https://gitlab.com/gitlab-com/runbooks/merge_requests/new?merge_request%5Bsource_branch%5D=postgres-load-update&merge_request%5Bsource_project_id%5D=1148549&merge_request%5Btarget_branch%5D=master&merge_request%5Btarget_project_id%5D=1148549#8452035bc25f2c38dbb46607f653f1d488008ce3_45_47