New Feature In Oracle 12 C - Pluggable Databases

In Oracle 12c, in a plug-gable database environment, we can create a single database container, and plug multiple databases into this container. All these databases then share the exact same oracle server/background processes and memory, unlike the previous versions where each database has its own background processes and shared memory. This helps in database consolidation and reduces the overhead of managing multiple desperate databases.

Container Database (CDB): Are the core data dictionary objects that come after an Oracle database installation.

Pluggable Database (PDB): Data dictionary objects and data related to the application. We can have many PDB plugged into a single CDB.

A new admin role "CDB Administrator" has been introduced in Oracle 12.1 release databases.

Multiple databases can then share a master LGWR process, but have their own dedicated LGWR process within the container.

All Oracle database options/features are available on the PDB level.

RMAN backup at CDB level.

We can unplug a PDB from a CDB to another CDB.

PDB's can be cloned inside the CDB.

Management of PDB (clone/creation/plug/unplug/drop) are implemented as SQLs.

Extremely fast PDB-provisioning (clone inside the CDB), because each CDB comes with a “PDB Seed”.

Database patch/upgrade management very quick as CDB is a single point of installation.

Each PDB has its own data dictionary.

Data Guard configuration on CDB as whole

RMAN point-in-time recovery at PDB level (while other PDB's remains open)

Resource Manager is extended for creating, unplugging, plugging in, and cloning, dropping or even setting up for the open mode of the PDB.   

Flashback of a PDB should be available for Oracle12c Release 2.

Entire containers can be backed up in single run, regardless of how many databases they contain.

Upgrade one container database and all pluggable databases are upgraded.

New Commands

create pluggable database
alter pluggable database
drop pluggable database