Merge branch '425975-drop-idx_namespaces_on_ldap_sync_last_successful_update_at' into 'master'

Drop namespaces_on_ldap_sync_last_successful_update_at for Gitlab.com

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/135040



Merged-by: Gregory Havenga <11164960-ghavenga@users.noreply.gitlab.com>
Approved-by: Terri Chu <tchu@gitlab.com>
Approved-by: Gregory Havenga <11164960-ghavenga@users.noreply.gitlab.com>
Co-authored-by: Prabakaran Murugesan <pmurugesan@gitlab.com>

db/docs/namespaces.yml

@@ -15,3 +15,6 @@ schema_inconsistencies:
 - type: missing_indexes
   object_name: index_namespaces_on_created_at
   introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/134948
+- type: missing_indexes
+  object_name: index_namespaces_on_ldap_sync_last_successful_update_at
+  introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/135040

db/migrate/20231109133153_drop_idx_namespaces_on_ldap_sync_last_successful_update_at_for_gitlab.rb

+# frozen_string_literal: true
+
+class DropIdxNamespacesOnLdapSyncLastSuccessfulUpdateAtForGitlab < Gitlab::Database::Migration[2.2]
+  milestone '16.6'
+
+  disable_ddl_transaction!
+
+  TABLE_NAME = :namespaces
+  INDEX_NAME = :index_namespaces_on_ldap_sync_last_successful_update_at
+
+  def up
+    return unless should_run?
+
+    remove_concurrent_index_by_name TABLE_NAME, INDEX_NAME
+  end
+
+  def down
+    return unless should_run?
+
+    add_concurrent_index TABLE_NAME, :ldap_sync_last_successful_update_at, name: INDEX_NAME
+  end
+
+  private
+
+  def should_run?
+    Gitlab.com_except_jh?
+  end
+end

db/schema_migrations/20231109133153

+fb17684ac5976811bd08e4a2edb3b3c45baaf293ee3c04e986ae3c197c59c54a
\ No newline at end of file