Add secondary indexes to partitioned audit_events

Add a new migration to create the secondary indexes on the partitioned
audit_events copy. This uses the partitioning migration helpers to
create an index on each partition before creating the index on the base
table.

changelogs/unreleased/241267-add-partitioned-audit-events-indexes.yml

+---
+title: Add secondary indexes to partitioned audit_events
+merge_request: 48270
+author:
+type: added

db/migrate/20201112215028_add_partitioned_audit_event_indexes.rb

+# frozen_string_literal: true
+
+class AddPartitionedAuditEventIndexes < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::PartitioningMigrationHelpers
+
+  DOWNTIME = false
+
+  CREATED_AT_AUTHOR_ID_INDEX_NAME = 'analytics_index_audit_events_part_on_created_at_and_author_id'
+  ENTITY_ID_DESC_INDEX_NAME = 'idx_audit_events_part_on_entity_id_desc_author_id_created_at'
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_partitioned_index :audit_events_part_5fc467ac26,
+      [:created_at, :author_id],
+      name: CREATED_AT_AUTHOR_ID_INDEX_NAME
+
+    add_concurrent_partitioned_index :audit_events_part_5fc467ac26,
+      [:entity_id, :entity_type, :id, :author_id, :created_at],
+      order: { id: :desc },
+      name: ENTITY_ID_DESC_INDEX_NAME
+  end
+
+  def down
+    remove_concurrent_partitioned_index_by_name :audit_events_part_5fc467ac26, ENTITY_ID_DESC_INDEX_NAME
+
+    remove_concurrent_partitioned_index_by_name :audit_events_part_5fc467ac26, CREATED_AT_AUTHOR_ID_INDEX_NAME
+  end
+end

db/schema_migrations/20201112215028

+d8d774e788eeaaecbda3cb7c5530926e74843d844bfad27b6a6e65bf5f89ac8a
\ No newline at end of file

db/structure.sql

@@ -20039,6 +20039,8 @@ CREATE INDEX active_billable_users ON users USING btree (id) WHERE (((state)::te
 
 CREATE INDEX analytics_index_audit_events_on_created_at_and_author_id ON audit_events USING btree (created_at, author_id);
 
+CREATE INDEX analytics_index_audit_events_part_on_created_at_and_author_id ON ONLY audit_events_part_5fc467ac26 USING btree (created_at, author_id);
+
 CREATE INDEX analytics_index_events_on_created_at_and_author_id ON events USING btree (created_at, author_id);
 
 CREATE INDEX analytics_repository_languages_on_project_id ON analytics_language_trend_repository_languages USING btree (project_id);
@@ -20083,6 +20085,8 @@ CREATE INDEX finding_links_on_vulnerability_occurrence_id ON vulnerability_findi
 
 CREATE INDEX idx_audit_events_on_entity_id_desc_author_id_created_at ON audit_events USING btree (entity_id, entity_type, id DESC, author_id, created_at);
 
+CREATE INDEX idx_audit_events_part_on_entity_id_desc_author_id_created_at ON ONLY audit_events_part_5fc467ac26 USING btree (entity_id, entity_type, id DESC, author_id, created_at);
+
 CREATE INDEX idx_ci_pipelines_artifacts_locked ON ci_pipelines USING btree (ci_ref_id, id) WHERE (locked = 1);
 
 CREATE INDEX idx_container_exp_policies_on_project_id_next_run_at_enabled ON container_expiration_policies USING btree (project_id, next_run_at, enabled);