Quote from Alex Dev on September 4, 2026, 15:07

Hello

Thank you for the process list output, that identified it immediately.

That query comes from the plugin. When the bulk editor opens, it builds the author drop-down for the filter and bulk edit panels. To do that it asks WordPress for every user holding a role that can publish, which on your client's site is six roles: administrator, editor, author, shop_manager, wpseo_manager and wpseo_editor. That is why you see six joins against wp_usermeta in the same statement.

One detail worth knowing. The meta keys in that query, wp_iufsr:administrator and so on, are not WordPress core. They are created by the plugin Index WP Users For Speed, which intercepts role based user queries and rewrites them to use its own index rows. So the statement your hosting team captured is that plugin's rewritten version of our query. Two things are worth checking on your side:

First, confirm that its background indexing has actually finished. It indexes users in WP_Cron batches, and until that completes the index rows are missing and the query has nothing to use.

Second, note that its approach adds one join per role. With six roles that is six self joins on wp_usermeta, which will be slow on a large user table regardless of indexing.

You do not need to wait for a plugin update to resolve this. The user query is filterable. Add this to the functions.php of the active theme, or to a small must-use plugin:

add_filter(
	'woobe_users_args',
	function ( $args ) {
		global $wpdb;

		$author_ids = wp_cache_get( 'woobe_product_author_ids' );

		if ( false === $author_ids ) {

			$author_ids = $wpdb->get_col(
				"SELECT DISTINCT post_author
				 FROM {$wpdb->posts}
				 WHERE post_type = 'product'
				   AND post_status IN ( 'publish', 'draft', 'pending', 'private' )"
			);

			$author_ids = array_map( 'intval', (array) $author_ids );

			wp_cache_set( 'woobe_product_author_ids', $author_ids, '', 3600 );
		}

		if ( empty( $author_ids ) ) {
			return $args;
		}

		return array(
			'fields'  => array( 'ID', 'display_name' ),
			'include' => $author_ids,
			'orderby' => 'display_name',
		);
	}
);

This removes the wp_usermeta joins entirely. The products table is queried by post_type, which is indexed, and the users are then fetched by primary key. It also produces a more useful drop-down, since it lists only people who actually own products rather than everyone with a publishing role.

If you want the simplest possible test first, before adding the code above, you can confirm the diagnosis in one line by returning a plain capped query instead:

add_filter( 'woobe_users_args', function ( $args ) {
   return array( 'fields' => array( 'ID', 'display_name' ), 'number' => 200 );
} );

 

If the 504 disappears with that, the user query is confirmed as the cause and you can move to the first snippet for the proper behaviour.

The filter is documented here: https://bulk-editor.com/document/more-settings-implicit

Please let us know the result either way.

add_filter( 'woobe_users_args', function ( $args ) {
   return array( 'fields' => array( 'ID', 'display_name' ), 'number' => 200 );
} );

Quote from Beth on September 7, 2026, 10:21

Hi Alex,

Thank you for coming back to me so quickly, it is much appreciated! The first filter works wonderfully, thank you and the plugin is working as exepcted again. Thank you for your help!

Quote from Alex Dev on September 7, 2026, 13:58

You are Welcome :)