Compare performance of query that retrieves posts by category [WordPress]

compare_cat_queries.php

//SZ Compare queries performance
// Function to fetch and display random posts using the initial slow method
function fetch_random_posts_initial() {
    $start_time = microtime(true);

    $args = array(
        'cat'                 => array(1, 9, 10, 11, 44, 94),
        'posts_per_page'      => 3,
        'no_found_rows'       => true,
        'ignore_sticky_posts' => true,
        'orderby'             => 'rand',
    );
    $news_query = new WP_Query($args);

    if ($news_query->have_posts()) { ?>
        <div class="teaser_wrap">
            <div class="teaser_news">
                <div class="news__inner">
                    <?php while ($news_query->have_posts()) : $news_query->the_post();
                        $thumb = wp_get_attachment_image_src(get_post_thumbnail_id(get_the_ID()), 'full');
                        if ($thumb) { ?>
                            <div class="news__item" style="background-image: url('<?php echo esc_url($thumb[0]); ?>')">
                                <a href="<?php the_permalink(); ?>" class="news__link">
                                    <span class="news__title">
                                        <?php the_title(); ?>
                                    </span>
                                </a>
                            </div>
                        <?php } ?>
                    <?php endwhile; ?>
                </div>
            </div>
        </div>
    <?php }
    wp_reset_postdata(); // Restore global post data stomped by the_post().

    $end_time = microtime(true);
    $execution_time = $end_time - $start_time;
    echo '<!-- Initial method execution time: ' . $execution_time . ' seconds. -->';
}

// Function to fetch and display random posts using the optimized WP_Query method
function fetch_random_posts_optimized() {
    $start_time = microtime(true);

    // Fetch random post IDs
    $categories = array(1, 9, 10, 11, 44, 94);
    $args = array(
        'cat'                 => $categories,
        'posts_per_page'      => 3,
        'orderby'             => 'rand',
        'fields'              => 'ids',
        'no_found_rows'       => true,
        'ignore_sticky_posts' => true,
    );
    $random_posts = new WP_Query($args);
    $random_post_ids = $random_posts->posts;

    // Fetch posts using the random IDs
    if ($random_post_ids) {
        $args = array(
            'post__in'            => $random_post_ids,
            'posts_per_page'      => 3,
            'orderby'             => 'post__in',
            'no_found_rows'       => true,
            'ignore_sticky_posts' => true,
        );
        $news_query = new WP_Query($args);

        if ($news_query->have_posts()) { ?>
            <div class="teaser_wrap">
                <div class="teaser_news">
                    <div class="news__inner">
                        <?php while ($news_query->have_posts()) : $news_query->the_post();
                            $thumb = wp_get_attachment_image_src(get_post_thumbnail_id(get_the_ID()), 'full');
                            if ($thumb) { ?>
                                <div class="news__item" style="background-image: url('<?php echo esc_url($thumb[0]); ?>')">
                                    <a href="<?php the_permalink(); ?>" class="news__link">
                                        <span class="news__title">
                                            <?php the_title(); ?>
                                        </span>
                                    </a>
                                </div>
                            <?php } ?>
                        <?php endwhile; ?>
                    </div>
                </div>
            </div>
        <?php }
        wp_reset_postdata(); // Restore global post data stomped by the_post().
    }

    $end_time = microtime(true);
    $execution_time = $end_time - $start_time;
    echo '<!-- Optimized WP_Query method execution time: ' . $execution_time . ' seconds. -->';
}

// Function to fetch and display random posts using a direct SQL query
function fetch_random_posts_sql() {
    global $wpdb;
    $start_time = microtime(true);

    $category_ids = implode(',', array(1, 9, 10, 11, 44, 94));
    $random_posts_query = "
        SELECT wp_posts.ID 
        FROM wp_posts 
        LEFT JOIN wp_term_relationships ON (wp_posts.ID = wp_term_relationships.object_id) 
        LEFT JOIN wp_term_taxonomy ON (wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id)
        WHERE wp_term_taxonomy.taxonomy = 'category' 
        AND wp_term_taxonomy.term_id IN ($category_ids) 
        AND wp_posts.post_type = 'post' 
        AND wp_posts.post_status = 'publish' 
        GROUP BY wp_posts.ID 
        ORDER BY RAND() 
        LIMIT 3
    ";

    $random_post_ids = $wpdb->get_col($random_posts_query);

    // Fetch posts using the random IDs
    if ($random_post_ids) {
        $args = array(
            'post__in'            => $random_post_ids,
            'posts_per_page'      => 3,
            'orderby'             => 'post__in',
            'no_found_rows'       => true,
            'ignore_sticky_posts' => true,
        );
        $news_query = new WP_Query($args);

        if ($news_query->have_posts()) { ?>
            <div class="teaser_wrap">
                <div class="teaser_news">
                    <div class="news__inner">
                        <?php while ($news_query->have_posts()) : $news_query->the_post();
                            $thumb = wp_get_attachment_image_src(get_post_thumbnail_id(get_the_ID()), 'full');
                            if ($thumb) { ?>
                                <div class="news__item" style="background-image: url('<?php echo esc_url($thumb[0]); ?>')">
                                    <a href="<?php the_permalink(); ?>" class="news__link">
                                        <span class="news__title">
                                            <?php the_title(); ?>
                                        </span>
                                    </a>
                                </div>
                            <?php } ?>
                        <?php endwhile; ?>
                    </div>
                </div>
            </div>
        <?php }
        wp_reset_postdata(); // Restore global post data stomped by the_post().
    }

    $end_time = microtime(true);
    $execution_time = $end_time - $start_time;
    echo '<!-- SQL query method execution time: ' . $execution_time . ' seconds. -->';
}

// Main function to call all methods and measure their performance
function compare_random_post_methods() {
    fetch_random_posts_initial();
    fetch_random_posts_optimized();
    fetch_random_posts_sql();
}

// Hook the main function to the 'wp_loaded' action to run once on page load
//add_action('wp_loaded', 'compare_random_post_methods');