1Z0-183 practice question 1 of 10

A database administrator executes the following command to unplug a PDB named PDB_FIN from a source CDB: ALTER PLUGGABLE DATABASE PDB_FIN UNPLUG INTO '/u01/transfers/pdb_fin.pdb'; What is the result of using the .pdb extension in the destination filename?

Answer options

A: It creates a proprietary RMAN backup set that must be restored using the RESTORE PLUGGABLE DATABASE command.

B: It creates a single compressed archive file containing both the XML metadata describing the PDB and the physical datafiles. Correct answer

C: It creates an XML metadata file only, requiring the administrator to manually copy the datafiles to the target location.

D: It creates a directory object in the database pointing to the live datafiles without performing any physical copy.

Correct Answer:

B. It creates a single compressed archive file containing both the XML metadata describing the PDB and the physical datafiles.

Explanation

When unplugging a Pluggable Database (PDB) using the ALTER PLUGGABLE DATABASE ... UNPLUG INTO command, specifying a destination filename with a .pdb extension instructs Oracle to create a PDB archive file. This archive is a single, compressed file (using a tar and gzip format) that contains both the XML metadata file describing the PDB's structure and a copy of all the PDB's physical datafiles. This creates a self-contained, portable package for easily moving the PDB to another CDB.

Why Incorrect

A. The .pdb archive is a standard compressed tarball (.tar.gz), not a proprietary RMAN backup set format.
C. Creating only an XML metadata file occurs when the specified filename has an .xml extension or an extension other than .pdb.
D. This command creates a portable file for transfer; it does not create a database directory object or point to live datafiles.

References

1. Oracle Database SQL Language Reference, 19c. "ALTER PLUGGABLE DATABASE", unplugclause. The documentation states: "If you specify a file name with a .pdb extension, then the database creates a PDB archive file... The PDB archive file is a compressed file that includes the XML file and the PDB's data files."

2. Oracle Database Multitenant Administrator’s Guide, 19c. Chapter 6, "Unplugging and Plugging In PDBs". The section "About Unplugging a PDB" describes the creation of a PDB archive file when using the .pdb extension.

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