I must thank my fellow DBA César Aguilar and Joel Pérez for his publication in Spanish OTN.

Continuing with the sequence of Oracle Data Guard 12c articles in “Multitenant” Architecture: PDBs behavior, we will end the series by analyzing what happens in the Data Guard “DG” when we delete and when we do an “unplug” of a PDB in the primary CDB.

We will propose the following objectives and scenarios:

Scenario 1: Delete the PDB1 on the primary CDB1 with “DG” configured.

Scenario 2: Unplug the PDB2 of the primary CDB1 with “DG” configured.

Usage Tool: SQL * Plus

Our test environment:

  • The primary CDB1 with “DG” configured has four pluggables: PDB1, PDB2, PDB_SERA and PDB_FINA.
  • The standby CDB1 that forms part of the “DG”.

 

Scenario 1: Delete PDB1 from the primary CDB1.

We entered the CDB1 of the DG.

We list the PDBs of the primary CDB1.

We proceed to delete the PDB1.

We verified that the PDB1 was deleted.

We enter the standby server of the “DG” where we have the standby CDB1.

We verify when listing the PDBs of our standby server that the PDB1 no longer exists as part of the “DG” solution.

Deleting the PDB1 in the primary CDB1 with the option “including datafiles” the datafiles were deleted in the servers: Primary and “Standby”

Scenario 2: “Unplug” the PDB2 of the primary CDB1.

We proceed to disconnect the PDB2 from the primary CDB1.

We list the PDBs, as we can see the PDB2 is in “MOUNTED” mode.

We will enter the CDB1standby to demonstrate that the datafiles of PDB2 remain.

When performing the unplug of the PDB2 on the primary CDB1, the datafiles of the PDB2 are maintained in the primary CDB1 and in the standby similar to the operation of deleting a PDB with the “keep datafiles” option.

The datafiles of a PDB that has been “unplugged” will be present since they should be copied to a destination where the “plug” would be made, these could be deleted later if they are not going to be used by deleting the PDB that has been “unplugged “.

Conclusion:

In this series of articles we analyzed different behaviors of the PDBs in a DG solution, we could see that under the multitenant architecture of Oracle 12c the PDBs associated to the primary CDB have different behaviors within the DG depending on the way they are created, connected, Deleted and disconnected.

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