SQL Cron is a Drupal module that allows you to create and manage a set of SQL statements that are executed during cron runs. The last execution time and execution result is displayed for each SQL statement. Any SQL statement that is valid for the Drupal db_query function can be used. This includes INSERT, TRUNCATE, UPDATE, DELETE, etc. This module is similar to the DB Cron module which hasn't been maintained since Drupal 4.7.
This module can be useful for pruning and updating custom database tables used by your Drupal installation. For example, you may want to periodically update information about your top rated or most viewed content in a custom table. You may have a log of user visits or actions that you want to truncate or prune periodically. SQL Cron provides you an easy method for accomplishing this without having to set up separate cron jobs on your web server.