In my WordPress, I have implemented a logic where each CPT shop_order has a post_meta called "luck_number". However, the issue arises when there are more than 1000 sales per post in this CPT. When I try to retrieve the post_meta with get_post_meta inside a while loop, the page takes around 15 minutes to load.
I conducted a test and found that the speed is acceptable when there are only a few post_meta. But as soon as we reach the thousands, it becomes significantly slower.
Is there a better approach to ensure good performance even in scenarios where there are thousands of post_meta per POST?
The relevant section of code looks like this:
<?php
$loop = new WP_Query( $args );
while ( $loop->have_posts() ) : $loop->the_post();
$numbers = get_post_meta(get_the_ID(),"luck_number",false);
$a = 0;
while($a<count($numbers)):
// DO SOMETHING WITH THE NUMBER
$a++;
endwhile;
endwhile;
wp_reset_query();
When each post contains an average of 0 to 500 numbers, everything works fine. However, when the count exceeds 1000, the performance degrades significantly.
I typically have 'posts_per_page' set at 25, but even reducing this number doesn't have much impact on the result. The server infrastructure (a reliable VPS) and PHP memory_limit (currently set to 1024M) do not seem to be major factors influencing the performance.