This topic describes the basic concepts involved with provisioning VDBs from PostgreSQL.

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, writable copy of a dSource snapshot. You can also create VDBs from other VDBs. Once you have provisioned a VDB to a target environment, you can also implement snapshot and retention policies for the VDB, which will determine how frequently Delphix Engine will take a database snapshot and how long the snapshots will be retained for recovery and provisioning purposes.

For an overview of the high-level components involved in provisioning a PostgreSQL VDB refer to Setting Up PostgreSQL Environments: An Overview.

Snapshots accumulate over time. To view a snapshot:

  1. From the Datasets pane, click the group containing the dSource.

  2. Select the dSource.

  3. Click the TimeFlow tab.

The TimeFlow appears as a list of dates, each of which expands to show snapshots from that date. Times, when the VDB has been refreshed, are marked by a blue line between dates.

On the TimeFlow, you can also filter by type of snapshot. To do so, click the filter button, which is shaped like an eye.

You can scroll through these lists to select the one you want, or you can enter a date and time to search for a specific snapshot.

Once you have provisioned a VDB, you can also take snapshots of it. As with the dSource snapshots, you can find these when you select the VDB in the Datasets panel. You can then provision additional VDBs from these VDB snapshots.

Dependencies

If there are dependencies on the snapshot, you will not be able to delete the snapshot free space; the dependencies rely on the data associated with the snapshot.