Hi Luis,
if you have enabled detail step logging in your scenario and/or have set log level to config in your xcellerator.cfg, which is very usefu for debugging, then B1if logs huge amount of informations in the database. Then the db grows and grows.
For production environment disable detailed step logging and set log level to severe in xcellerator.cfg.
Consider also to save all your scenarios, uninstall and reinstall b1if to start over with a new db, then import your scenarios.
Regards
Pierre