This tab allows you to separate all tables and other database objects related to contact management and have them hosted in an independent database. Because the contact management records may in some cases take up a very large volume of data, using a separate database makes it easier to administer the application's main database (e.g. when performing regular backups).
To start the separation procedure, click the Separate contact management database button.
If the contact management database is already separated, you can rejoin it with the application's main database by clicking the Join contact management DB with main DB button.
It is strongly recommended to backup your database(s) before performing either of these actions.
Additionally, please note that all websites in the system will temporarily need to be brought offline during the separation or joining process. Ideally, it should be performed at a time when no visitors or editors are accessing the websites.
More resources can be found in On-line marketing guide -> Contact management -> Database separation.