How does WordPress handle the N+1 query problem with post meta, and what is the recommended approach?

Question

WordPress Fundamental — Hard

How does WordPress handle the N+1 query problem with post meta, and what is the recommended approach?

Accepted Answer

WordPress lazy-loads post meta by default, leading to N+1 queries. The recommended approach is to use 'update_meta_cache' => true in WP_Query or get_post_meta() with array return to batch-load all meta in one query, or use 'no_found_rows' and meta_query with EXISTS checks.