Merge branch 'restore-accidentally-deleted-index' into 'master'

Restore accidentally removed index

See merge request gitlab-org/gitlab!44266

db/structure.sql

@@ -19445,6 +19445,8 @@ CREATE UNIQUE INDEX idx_jira_connect_subscriptions_on_installation_id_namespace_
 
 CREATE INDEX idx_members_created_at_user_id_invite_token ON members USING btree (created_at) WHERE ((invite_token IS NOT NULL) AND (user_id IS NULL));
 
+CREATE INDEX idx_merge_requests_on_id_and_merge_jid ON merge_requests USING btree (id, merge_jid) WHERE ((merge_jid IS NOT NULL) AND (state_id = 4));
+
 CREATE INDEX idx_merge_requests_on_source_project_and_branch_state_opened ON merge_requests USING btree (source_project_id, source_branch) WHERE (state_id = 1);
 
 CREATE INDEX idx_merge_requests_on_state_id_and_merge_status ON merge_requests USING btree (state_id, merge_status) WHERE ((state_id = 1) AND ((merge_status)::text = 'can_be_merged'::text));