Cache metadata for set of posts

Question

I have a query that can only be done using straight SQL, but I need to loop through the returns as a set of posts. As I understand it, WP_Query automatically gets all the metadata for all the posts retrieved, and caches it for when get_post_meta is called. But since I have to use wpdb->query, I was wondering if there was anyway I could call another function after it with a set of like post ids, which would cache all their meta; this way I don't hit the database for every post in the loop.

Right now I am actually inner joining the fields I need from the post_meta, but this just seems like a bad (and messy) idea.

Thanks,
Max

Answer 1

I did a lot of digging into wordpress, and it looks like WP_Query ends up calling (indirectly) update_postmeta_cache($postIDs); which looks like it is exactly what I need.

Hope that helps somebody else out. In 3.5.1 it's located in wp-includes/post.php#2735.