BUG: _prime_post_caches

[maciejmackowiak]

Describe the bug

When the get_es_posts runs shouldn't there also be a call to _prime_post_caches?

While testing backend search in wp admin posts list using EP plugins adds ton of additional queries for posts, posts meta, terms meta etc. while the default wp query is using the prime post caches function and do it in a bulk.

For now we added this as a workaround:

add_action('ep_wp_query', function ($new_posts) {
    $post_ids = [];
    foreach ($new_posts as $key => $post) {
        $post_ids[]= (int) $post->ID;
    }
    _prime_post_caches($post_ids);
});

Steps to Reproduce

Described above.

Screenshots, screen recording, code snippet

No response

Environment information

No response

WordPress and ElasticPress information

No response

Code of Conduct

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[felipeelia]

Hey @maciejmackowiak! I'm not 100% sure what you would be trying to achieve with that. Do you mind expanding on it a bit? We would not want to make additional calls to the database after calling ES because one of the main reasons for using ES is to actually avoid that, but perhaps I'm misunderstanding your point. Thanks!

[maciejmackowiak]

Hey @felipeelia
we don't have object cache enabled so when we get search results from EP plugin on the backend (in the posts list page) we get ton of additional queries - even more then when EP plugin is disabled.
WP by default runs the _prime_post_caches when returning the results - it only updates the caches for posts that are not already cached (it runs first the _get_non_cached_ids in _prime_post_caches).

So the number of queries will not increase at all when all posts/terms are already in the object cache but it will decrease if more then 1 posts is not cached - currently without priming the caches WP instead of doing the query in bulk for all posts it queries for each posts and associated term.

https://github.com/WordPress/WordPress/blob/master/wp-includes/post.php#L8230

[burhandodhy]

Hi @maciejmackowiak,

Thanks for sharing the context. I will review this further and update the bug once I have an update.

Regards,
Burhan