Admin posts overview (edit.php) for hierarchical custom post type loads all posts

[engelen]

It seems as though the admin posts overview for hierarchical post types loads all available posts for the post type through WP_Query. Backtracing from WP_Posts_List_Table::prepare_items leads to wp_edit_posts_query in wp-admin/includes/post.php, which has at the end of the function.

	if ( is_post_type_hierarchical( $post_type ) && !isset($orderby) ) {
		$query['orderby'] = 'menu_order title';
		$query['order'] = 'asc';
		$query['posts_per_page'] = -1;
		$query['posts_per_archive_page'] = -1;
	}

It stems from the original edit-pages.php file, which was merged in 2010 (​https://github.com/WordPress/WordPress/commit/05bf7382ff9a02837cf15030689bd6c613927c01).

So, basically, for hierarchical post types, the posts overview loads all posts from the database (or from cache). Has this ever come up before in Trac ([it has in forums](​https://wordpress.org/support/topic/why-is-wp_edit_posts_query-queryposts_per_page-1?replies=5))? It seems incredibly inefficient and could possibly slow down (or bring down) servers.

[SergeyBiryukov]

Duplicate of #15459.