I have a website centered around music. I have 3 main post types- ‘Artist’, ‘Release’, and ‘Version’. There are 4 types of ‘Version’- album, single, video, misc.

Artist is parent of Release. (artist has a single -> many relationship with releases)
Release is a parent of Version. (Release has a single-> many relationship with version)

I’ve established these relationships in the plugin toolset types.

In my single-artist page, I have releases displayed in sections. Here’s an example of the code to display all albums by an artist.

<?php 
$album_args = array(
    'post_per_page' => -1,
    'tax_query' => array(
        array(
            'taxonomy' => 'release-format',
                        'field' => 'slug',
            'terms' => 'album',
            
        ),  
    ),
);

$album_posts = types_child_posts('release', $album_args);

// sort alphabetically by firstname and lastname
usort($album_posts, 'compare_fullname');
    $url = esc_url( home_url() );
?>
<div class="row row-cols-1   justify-content-center">
    <?php foreach ($album_posts as $child_post)  {      ?>
    
    <div class="col py-1">
        <?php include get_template_directory() . '/includes/containers/artist-page-container.php' ;?>
        <?php 
        $versionID= $child_post->ID;
        $version_count = array(
            'post_type' => 'album',
            'post_per_page' => -1,
            'meta_query' => array(
                array(
                    'key' => '_wpcf_belongs_release_id',
                    'value' => $versionID,
                )
            ),
        );

    $version_counter = types_child_posts('release', $version_count);
    $count=0;
    foreach ($version_counter as $counter_child_post  )  {    
        $count++;
    } 
    if ($count==1){
        echo "$count version";
    }else{
        echo "$count versions";
    }
                                
    ?>
</div>
<?php } ?>

So… In the foreach loop, while it is going through a release- it takes a new dive into all the child posts of this release.

This count is VERY slow, when I add this count into each section, it can take 15 seconds or more for a big artist page to load. What is a better way to count these?

I think, specifically, I need to lose the meta_query and the _wpcf_belongs_release_id and instead replace it with a different way of finding all the related child posts of this post. Is there a better way to do this?

The amount of versions doesn’t change until I upload a new version (not often).

Is there a way to run this count BEFORE the user ever sees the page? Can I run the count on the admin side and just associate the final number with the release as a meta_field or some such thing?

Thanks!