Benchmark update_meta_cache SQL query with and without ORDER BY $id_colurmn param

gistfile1.php

<?php

// Use this to create a load of meta entries to check its still OK when there are loads of meta entries.
// for ( $i = 0; $i < 500; $i++ ) {
// 	$id = 'test-' . uniqid();
// 	add_post_meta( 1, $id, rand() );
// }

// die();

global $wpdb;

$query = "SELECT post_id, meta_key, meta_value FROM $wpdb->postmeta WHERE post_id IN (1)";

wp_cache_flush();

$start = microtime(true);

for ( $i = 0; $i < 1000; $i++ ) {
	
	$results = $wpdb->flush();
	$results = $wpdb->get_results( $query );

}

$end = microtime(true);

hm( round( $end - $start, 3 ) );

$query = "SELECT post_id, meta_key, meta_value FROM $wpdb->postmeta WHERE post_id IN (1) ORDER BY meta_id";

wp_cache_flush();

$start = microtime(true);

for ( $i = 0; $i < 1000; $i++ ) {
	
	$results = $wpdb->flush();
	$results = $wpdb->get_results( $query );	

}

$end = microtime(true);

hm( round( $end - $start, 3 ) );