This topic describes the basic concepts involved with provisioning VDBs from SQL Server dSources.
A dSource is a virtualized representation of a physical or logical source database. As a virtual representation, it cannot be accessed or manipulated using database tools. Instead, you must create a Virtual Database (VDB) from a dSource snapshot. A VDB is an independent, writeable copy of a dSource snapshot. You can also create VDBs from other VDBs. Once a VDB has been provisioned to a target environment, you can also implement a snapshot policy for that VDB, to capture changes within it as if it were any other logical or physical database.
For an overview of the high-level components involved in provisioning a SQL Server VDB refer to Setting Up SQL Server Environments: An Overview.
Validated Sync and LogSync
When you link a source database into Delphix, you must also specify a target environment that will host a staging database for the validated sync process, as described in Setting Up SQL Server Environments: An Overview. In this process, the Delphix Engine continuously monitors the source database for new transaction log backups. When it detects one, it restores that backup to the staging database. The result is a TimeFlow with consistent points from which you can provision a VDB, also known as snapshots.
Snapshots accumulate over time, and are available when you select the dSource in the My Databases panel of the Delphix Admin application. Each snapshot is represented as a card that includes information about the source database, operating system, end stamp, and snapshot database change number (SCN for Oracle and LSN for SQL Server). You can scroll through these cards to select the one you want, or enter a date and time to search for a specific snapshot.If LogSync is enabled, you will also see a LogSync slider control at the top of the snapshot card. If you slide this control to the right to open LogSync, you will see a pointer that you can move along a timeline to select the exact time from which you want to provision a VDB.
Once a VDB has been provisioned, you can also take snapshots of it. As with the dSource snapshots, you can find these when you select the VDB in the My Databases panel. You can then provision additional VDBs from these VDB snapshots.