perlQuestionnaire allows you to backup and restore your perlQ database. The Restore Bevahior applies to both Restore Data File and Restore From URL. There are two options:

Restore Data: SAVING ALL Current perlQ Data
This is the default option and ensures that you will lose no data that is currently in your perlQ database. When using this option, no data will be imported to the perlQAdmin table (which covers all perlQ Configuration variables and your password). Only individual surveys, questions, and results will be restored. Furthermore, if any clashing survey ids, question ids or user ids are found, new ones will be generated. This is the safest option for a restore, but will also leave your current data in the database and has the potential to change the URLs you may have used to link to your backed up surveys.

Restore Data: ERASING ALL Current perlQ Data
WARNING! This action cannot be undone. ALL DATA currently in perlQ will be erased and the data found in your backup file will be the only data placed into the restored database. This script will actually drop the current perlQ tables in your database, erasing all data and then insert all of your backup data. This function has the advantage of maintaining all survey, question and user ids in the data and replicating your database exactly as it appeared when you backed it up. Your password will be kept the same. Keep in mind that you may want to backup your current database before erasing all existing data, in case you later find there was information you wanted.