This technique uses the XML metadata file that describes the PDB and the files associated with the PDB to associate it with the CDB.The following figure illustrates plugging in an unplugged PDB.You can only create a PDB in a CDB and not within another PDB.The following figure depicts the options for creating a PDB. In this case, Oracle Database does not make a complete copy of source data files, but creates a storage-level snapshot of the underlying file system, and uses it to create PDB clones. The following SQL statement clones a PDB named In its unplugged state, a PDB is a self-contained set of data files and an XML metadata file.The DBA team is reduced from five to three, with one CDB administrator managing the CDB while two PDB administrators split management of the PDBs.data dictionary metadata specific to a PDB in the PDB itself rather than storing all dictionary metadata in one place.To show the problem in reduced scale, Figure 17-2 depicts 11 databases, each with its own application and server.

Optimized for infrastructure and communication applications as well as administration and small file server, this 1U systems features up to 64 GB RAM, up to 3 PCIe slots and up to 10 hard disk drives.

For example, 100 servers may have one database each, with each database using 10% of hardware resources and 10% of an administrator's time.

A team of DBAs must manage the SGA, database files, accounts, security, and so on of each database separately, while system administrators must maintain 100 different computers.

Thus, the users, administrators, and developers of a non-CDB have substantially the same experience after the database has been consolidated.

The following figure depicts the databases in Figure 17-2 after consolidation onto one computer.