Taking a Snapshot
On initiating a sync, Delphix Engine checks the staging server for the database of the given name and if a match is found, it then takes a snapshot of its data files. Before and after taking the snapshot, Delphix Engine runs a few validations to check the readiness and consistency of the database for the snapshot.
Below are the checks performed by Delphix Engine during snapshot operation:
The staging database is in the
READ ONLY WITH APPLYmode
All data files are present on the Delphix Engine mounted storage
For a non-standby staging database, checkpoint SCN of all online datafiles is the same
The database must be recovered and no data files must be in
Checkpoint SCN must have advanced since the last snapshot was taken
Checkpoint SCN has not advanced during the snapshot operation
CDB dSource snapshots cannot be taken manually. A PDB dSource snapshot operation takes a CDB dSource snapshot first before taking a PDB snapshot.
Taking an incremental snapshot
The staging database can be populated further by:
Restoring incremental backups
Through ongoing managed recovery in case of Physical Standby databases
After the staging database is populated with incremental changes, a snapshot operation will take an incremental snapshot of the dSource.