Selective data distribution is a flexible tool that allows you to move dSources and virtual databases (VDBs) between Delphix Engines. Selective data distribution relies on the replication infrastructure to transmit masked data, as such selectively distributed data has much of the same capabilities as replicated data. These topics describe several different use cases for selective data distribution.
Geographically Distributed Development
The Delphix Engine allows you to provision VDBs from distributed dSources and VDBs, as described in Provisioning from Replicated Data Sources or VDBs. This allows dSources that are linked in a single central location to be geographically distributed so that developers can provision VDBs remotely without having to sync from the source database in multiple locations. Selective distribution ensures that masked VDBs are sent to the target without transmitting the original unmasked source. As such, the original unmasked source will not be accessible on the target.
Selective data distribution does not support failover. In this environment, the link between the source and the target is never broken, except when remote VDBs need to be preserved. You can refresh remote VDBs as long as the parent objects continue to exist on the source. If they are deleted, then remote VDBs will continue to function but cannot be refreshed.
Because there is no failover, this technology can support more complex topologies such as 1-to-many and many-to-1. Chained distribution (replicating from Site A -> Site B -> Site C) is not supported.
For geographical distribution, follow these best practices:
- Because each replication stream induces load on the source system:
- Minimize the number of simultaneous replication updates
- If possible, avoid heavy VDB workloads on the source
- On the target, the provision only from sources that are effectively permanent. If a source is deleted remote VDBs can no longer be refreshed.
- Provision additional storage capacity on the target
- Remotely provisioned VDBs can consume shared storage on the target even when the parent is deleted on the source
You cannot use selective data distribution for data migration. Full replication is needed for data migration.