Add index on starts_at/ends_at for oncall shifts

changelogs/unreleased/sy-add-shift-timeframe-index.yml

+---
+title: Add index to incident management oncall shifts table
+merge_request: 52961
+author:
+type: performance

db/migrate/20210129225244_add_index_to_oncall_shfts_on_starts_at_and_ends_at.rb

+# frozen_string_literal: true
+
+class AddIndexToOncallShftsOnStartsAtAndEndsAt < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  NEW_NAME = 'index_oncall_shifts_on_rotation_id_and_starts_at_and_ends_at'
+  OLD_NAME = 'index_incident_management_oncall_shifts_on_rotation_id'
+
+  def up
+    add_concurrent_index :incident_management_oncall_shifts, %i[rotation_id starts_at ends_at], name: NEW_NAME
+
+    remove_concurrent_index_by_name :incident_management_oncall_shifts, OLD_NAME
+  end
+
+  def down
+    add_concurrent_index :incident_management_oncall_shifts, :rotation_id, name: OLD_NAME
+
+    remove_concurrent_index_by_name :incident_management_oncall_shifts, NEW_NAME
+  end
+end

db/schema_migrations/20210129225244

+6cb54c71a9835ec1b3cf801a19c2cd385d224e0438c7924b6a29d298ecebe8a7
\ No newline at end of file

db/structure.sql

@@ -22130,8 +22130,6 @@ CREATE INDEX index_incident_management_oncall_schedules_on_project_id ON inciden
 
 CREATE INDEX index_incident_management_oncall_shifts_on_participant_id ON incident_management_oncall_shifts USING btree (participant_id);
 
-CREATE INDEX index_incident_management_oncall_shifts_on_rotation_id ON incident_management_oncall_shifts USING btree (rotation_id);
-
 CREATE UNIQUE INDEX index_index_statuses_on_project_id ON index_statuses USING btree (project_id);
 
 CREATE INDEX index_insights_on_namespace_id ON insights USING btree (namespace_id);
@@ -22578,6 +22576,8 @@ CREATE INDEX index_onboarding_progresses_for_verify_track ON onboarding_progress
 
 CREATE UNIQUE INDEX index_onboarding_progresses_on_namespace_id ON onboarding_progresses USING btree (namespace_id);
 
+CREATE INDEX index_oncall_shifts_on_rotation_id_and_starts_at_and_ends_at ON incident_management_oncall_shifts USING btree (rotation_id, starts_at, ends_at);
+
 CREATE INDEX index_open_project_tracker_data_on_service_id ON open_project_tracker_data USING btree (service_id);
 
 CREATE INDEX index_operations_feature_flags_issues_on_issue_id ON operations_feature_flags_issues USING btree (issue_id);