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Dataguard PDB level failover support for Multitenant Oracle 19c

user591200 Member Posts: 42 Bronze Badge
edited Aug 11, 2021 10:02PM in Data Guard


Multitenancy has been a driving topic but there is not much of clear direction on how the HA is implemented for Multitenancy.

The general approach seems to be CDB level failover to standby , so the failover takes place at CDB to CDB , in an event where a single PDB is experiencing an issue , we will have to failover the whole instance ..this will impact all PDB's on the CDB.

next option seems to be with "refreshable PDB" , then I don't know how the log transfer happens , I am unable to find clear direction on this approach.

Is there a way to accomplish PDB level failover with Dataguard or how to minimize failover time with refreshable PDB's ?

The refreshable PDB's seems to be available only on Oracle Exadata/ODA or Oracle Cloud Service. Is my understanding correct or is it available on Oracle enterprise edition for all 19c supported platforms ?


  • brian.mcginity
    brian.mcginity Member Posts: 140 Bronze Badge
    edited Apr 14, 2022 2:00PM

    I've been wondering sort of the same thing.

    I contacted and asked if their product could handle DG at the PDB level. Specifically, I asked to set up DG from one PDB to another PDB (on another server). They think this is possile.

    Sounds like you want to set up DG on the CDB and failover to just a single PDB without failing over the other PDBs. That sounds much more complex.

  • Jan Klinke
    Jan Klinke Member Posts: 1 Blue Ribbon

    Just to provide clear answer here: Dbvisit handles PDB synchronization through synchronization of CDB. If you have 19c SE2 and 3 PDBs inside single CBD, you can't split the synchronization to multiple standby CDBs. For example it's not possible to synchronize PDB1 to standby CDB X and PDB2 to standby CDB Y.

    That goes also for Failover operation. It's whole CDB or nothing. You can't activate only single PDB (as the whole concept works on CDB level).

  • User_WWV1N
    User_WWV1N Member Posts: 2 Red Ribbon

    I am trying to use DG Broker to SWITCHOVER from one CDB (PRIMARY) to another CDB STANDBY.

    When I do ...


    Connecting to instance "STANDBYDB" on database "STANDBYDB" ...

    Unable to connect to database using (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(


    ORA-12521: TNS: listener does not currently know of instance requested in connect descriptor


    Warning: Cannot connect to instance "STANDBYDB" on database "STANDBYDB".

    Connecting to instance "STANDBYDB" on database "STANDBYDB" ...

    ORA-01017: invalid username/password; logon denied

    Logged in as dgmgrl SYS/"X1_X2"...

    Error code: ORA-24542

    Description: PRELIM mode logon not allowed to a pluggable database

    Cause: PRELIM mode logon was attempted to a pluggable database.

    Action: Create PRELIM mode connections to CDB$ROOT only.

    What action should I take to VALIDATE the NETWORK?

    I haven't found any direction on how to "Create PRELIM mode connections to CDB$ROOT"

  • LaserSoft
    LaserSoft ChennaiMember Posts: 270 Silver Badge

    Hi user591200

    Greetings !!!

    Please have a look PDB level is available from 21.7 and also go through you will get some idea.