Display the Number of SQL Queries on Your blog:

The problem. When trying to optimize your blog’s loading time, knowing the number of queries made to the database is important. In order to reduce queries, the first thing to know is how many queries are made on a single page.

The solution.

1. This time, no need to log in to phpMyAdmin. Simply open the footer.php file in your theme and append the following lines of code:

   <?php if (is_user_logged_in()) { ?>
       <?php echo get_num_queries(); ?> queries in <?php timer_stop(1); ?> seconds.
   <?php } ?>

2. Save the file and visit your blog. In the footer, you’ll see the number of queries made to the WordPress database as well as the time it took to make them.

Explanation. Seems that many WordPress users aren’t aware of this useful function. The get_num_queries() function returns the number of executed queries during a page load.

Note that the above code will only display the number of queries to logged-in users, because regular visitors and search engine bots don’t need to know about it. But, if you’d like to make it public, simply remove the if (is_user_logged_in()) conditional instruction.