VistaDB is the embedded database option used by MDrivenServer for its admin database, intended for administrators who need a server startup database that also works beyond Windows.

What VistaDB stores

MDrivenServer uses an admin database to store application administration data, including the model and its metadata, user accounts, roles, and access rights. VistaDB stores this admin database in the file DatabaseVistaDB.vdb6.

For example, if you upload a model and create server users, those administrative records belong in the admin database. This is different from the application's business data, such as orders or customers. See Documentation:MDriven Backup & Restore Guide for the distinction between the admin database and user database, and for backup and restore procedures.

VistaDB and SQL Compact

VistaDB replaces SQL Compact as the embedded admin-database choice when MDrivenServer starts with no valid admin database. SQL Compact can be retained on Windows, but it does not work on Linux or macOS.

Option	Admin database file	Platform note
VistaDB	DatabaseVistaDB.vdb6	Use this option when the server must run on Linux or macOS.
SQL Compact	DatabaseCompact.sdf	This option works on Windows only; it does not work on Linux or macOS.

How MDrivenServer selects an admin database

When MDrivenServer starts and has no valid admin database, it chooses a startup database based on the VistaDB marker file.

1. If UseVistaDBIfThisFileExists.xml is present, MDrivenServer copies DatabaseVistaDB_TkStartDb.vdb6 to DatabaseVistaDB.vdb6.
2. MDrivenServer then uses DatabaseVistaDB.vdb6 as its admin database on subsequent starts.
3. If the VistaDB marker file is not present, MDrivenServer copies DatabaseCompact_TkStartDb.sdf to DatabaseCompact.sdf and uses SQL Compact as its admin database.

Do not remove or rename a current database file unless you intend MDrivenServer to initialize or select a different admin database. The current admin database contains server administration data.

Switch from VistaDB to SQL Compact on Windows

Use this procedure only when you are running MDrivenServer on Windows and need to return to SQL Compact.

1. Back up the current admin database before making changes. Follow the backup and restore guide to create and download an admin-database snapshot.
2. Stop MDrivenServer.
3. Open the MDrivenServer/App_Data directory.
4. Rename or move DatabaseVistaDB.vdb6 so that MDrivenServer cannot find it. Keep the file in a safe backup location if you may need to return to the VistaDB-based server state.
5. Rename the UseVistaDBIfThisFileExists.xml marker file so that it is no longer present under that name.
6. Start MDrivenServer.

With no VistaDB marker and no active VistaDB admin database, MDrivenServer creates the SQL Compact admin-database file from DatabaseCompact_TkStartDb.sdf as described above.

Important considerations

• Changing the admin-database selection does not preserve the contents of the concealed database automatically. Back it up before switching.
• Do not choose SQL Compact for a Linux or macOS deployment.
• In a container deployment, account for VistaDB behavior when configuring health checks. See Documentation:Deploying MDriven Server and Turnkey with Docker.
• This page concerns the MDrivenServer admin database. For SQL Server persistence mapping, see Documentation:SQL Server.

See also

• Documentation:MDriven Backup & Restore Guide
• Documentation:Deploying MDriven Server and Turnkey with Docker
• Documentation:SQL Server
• Education:TheIndex