12
Sorry, Yep
Go to your host´s control panel and look for Databases > phpMyAdmin (or any other app that controls you DB).
Click on it and once in the app look for your XOOPS db. Click on it, scroll down and look for a checkbox named "check all", clickon it look at your right and you´ll find a drop down menu with some functions. Find the ones labled "repair tables" and "otmize table".
I hope it helps
BTW . if you´re still usaing XOOPS 2014 look for a nice and old module "DBtools" It´s pretty handy once you logged.