M-Files uses Firebird as the default vault database engine. It is recommended, however, to use Microsoft SQL Server as the database engine for vaults that contain several hundreds of thousands of objects. If a vault has originally been set up to use Firebird but the number of objects in the vault has significantly increased, it might be beneficial to have the vault use Microsoft SQL Server as the database engine instead. You can migrate your vault database from Firebird to Microsoft SQL Server via M-Files Admin.
To migrate your vault database from Firebird to Microsoft SQL Server: