OCP Core Administration And Cdb Pdb Architecture Practice Test 4 — 15 Questions

Question 1

Which THREE features are specific to the Multitenant architecture and distinguish a CDB from a non-CDB?

Accepted Answer

Shared background processes for all PDBs. Option C is correct because in a multitenant CDB, all pluggable databases share the same set of background processes (e.g., PMON, SMON, DBWn, LGWR) belonging to the CDB instance, which is a defining characteristic that distinguishes a CDB from a non-CDB. Option D is correct because the multitenant architecture introduces CDB_ prefixed data dictionary views (such as CDB_TABLES, CDB_USERS, CDB_PDBS) that provide cross-container administrative monitoring, which do not exist in a non-CDB. Option E is correct because DBCA in a multitenant environment supports cloning a PDB (via PDB creation from an existing PDB or remote clone), a capability specific to the multitenant architecture. Option A is incorrect because PDBs do not each have their own SGA; they share the single SGA of the CDB instance. Option B is incorrect because PDBs are identified by a unique PDB name within the CDB, not by a unique SID; the SID belongs to the CDB instance.

Answer

The use of a separate SGA for every PDB

Answer

The requirement for a unique SID for each PDB

Question 2

You are preparing to create a new PDB named DEVPDB in your CDB, and you want it to be created as a clone of an existing PDB named APPPDB while APPPDB remains fully available to users. Which CREATE PLUGGABLE DATABASE clause accomplishes this?

Accepted Answer

CREATE PLUGGABLE DATABASE DEVPDB FROM APPPDB;. Cloning a local PDB while keeping the source online is done with CREATE PLUGGABLE DATABASE ... FROM source_pdb. The FROM clause reads the source's files and creates a new container without closing the original. The other choices either use invalid syntax or describe remote or unplugged-source operations that do not fit this scenario.

Answer

CREATE PLUGGABLE DATABASE DEVPDB USING '/tmp/apppdb.xml';

Answer

CREATE PLUGGABLE DATABASE DEVPDB COPY FROM APPPDB@REMOTE;

Answer

CREATE PLUGGABLE DATABASE DEVPDB AS CLONE OF APPPDB;

Question 3

You are preparing to plug an unplugged PDB into a new CDB named NEWCDB. Before you run CREATE PLUGGABLE DATABASE, you want to verify that the XML metadata file describing the unplugged PDB is well-formed and that the datafiles it references exist in the expected location. Which view should you query from the CDB root to inspect the contents of an unplugged PDB's metadata while it is still unplugged?

Accepted Answer

DBA_PDBS. DBA_PDBS is the dictionary view that tracks every PDB known to the CDB, including those in UNPLUGGED status, and it exposes the path to the PDB's XML metadata file. This lets an administrator confirm that the metadata is present and well-formed before performing CREATE PLUGGABLE DATABASE ... USING. The dynamic performance views focus on running containers and do not expose unplugged metadata details.

Answer

V$PDBS

Answer

CDB_PDBS

Answer

V$CONTAINERS

Question 4

You are the lead DBA for a CDB called PRODCDB. You need to relocate a PDB named SALESPDB to a different host. The PDB is currently open and has active transactions. You plan to unplug it. Which statement should you execute to ensure the PDB is in a consistent state for unplugging?

Accepted Answer

ALTER PLUGGABLE DATABASE SALESPDB UNPLUG INTO '/tmp/salespdb.xml';. To relocate a PDB, you must unplug it, which requires generating an XML metadata file and ensuring the data files are consistent. The ALTER PLUGGABLE DATABASE ... UNPLUG INTO command performs a clean close, checkpoints the data files, and creates the XML file. This single command is the correct approach. Other options either do not fully prepare the PDB or include redundant steps that could cause issues.

Answer

ALTER PLUGGABLE DATABASE SALESPDB CLOSE IMMEDIATE;

Answer

ALTER PLUGGABLE DATABASE SALESPDB CLOSE;

Answer

ALTER PLUGGABLE DATABASE SALESPDB CLOSE IMMEDIATE; ALTER PLUGGABLE DATABASE SALESPDB UNPLUG INTO '/tmp/salespdb.xml';

Question 5

You are managing a multitenant container database (CDB) with several pluggable databases (PDBs). You want to create a new PDB named HRPDB from the seed PDB. Which command correctly creates the PDB and leaves it in a mounted state?

Accepted Answer

CREATE PLUGGABLE DATABASE HRPDB FROM SEED ADMIN USER hr_admin IDENTIFIED BY password;. The CREATE PLUGGABLE DATABASE command with FROM SEED and ADMIN USER creates a new PDB from the seed and leaves it mounted. The OPEN clause would open it, which is not desired. The command without ADMIN USER is valid but less complete. The correct answer includes the ADMIN USER clause and does not include OPEN.

Answer

CREATE PLUGGABLE DATABASE HRPDB FROM SEED ADMIN USER hr_admin IDENTIFIED BY password OPEN;

Answer

CREATE PLUGGABLE DATABASE HRPDB ADMIN USER hr_admin IDENTIFIED BY password;

Answer

CREATE PLUGGABLE DATABASE HRPDB FROM SEED;

Question 6

You are the lead DBA for a CDB named PRODCDB. A developer has created an application PDB named APP1 and now reports that their application cannot connect to it. Upon investigation, you run the following query:

SELECT name, open_mode FROM v$pdbs WHERE name = 'APP1';

Output:
NAME   OPEN_MODE
APP1   MOUNTED

The PDB has no local undo tablespace and its datafiles are all online. What is the most direct cause of the connection failure?

Accepted Answer

The PDB is in MOUNTED state, so its data dictionary is not open for user access.. A PDB in MOUNTED state has its datafiles and control file opened, but its data dictionary is not fully accessible for user connections. Applications require the PDB to be in READ WRITE or READ ONLY mode. The v$pdbs view shows OPEN_MODE as MOUNTED, which is the direct cause. Opening the PDB with ALTER PLUGGABLE DATABASE APP1 OPEN resolves the issue.

Answer

The PDB's datafiles are offline, so Oracle automatically mounted the PDB without opening it.

Answer

The PDB's local undo tablespace is missing, preventing it from being opened in READ WRITE mode.

Answer

The PDB is in MOUNTED state because the CDB root is not open, preventing PDB access.

Question 7

You are a DBA for an Oracle 23ai CDB. You need to create a new PDB named TESTPDB from the seed PDB. Which command should you use?

Accepted Answer

CREATE PLUGGABLE DATABASE TESTPDB ADMIN USER pdbadmin IDENTIFIED BY password;. The CREATE PLUGGABLE DATABASE command with a PDB name and the ADMIN USER clause creates a new PDB from the seed. This is the standard and correct syntax. The other options contain invalid syntax or use the wrong command.

Answer

CREATE PLUGGABLE DATABASE TESTPDB CLONE FROM PDB$SEED;

Answer

CREATE DATABASE TESTPDB AS PLUGGABLE DATABASE;

Answer

CREATE PLUGGABLE DATABASE TESTPDB FROM SEED;

Question 8

You are managing a CDB and need to create a new PDB by cloning an existing PDB named SOURCEPDB. The clone should be named CLONEPDB and should be created from the local PDB without any intermediate files. Which command should you use?

Accepted Answer

CREATE PLUGGABLE DATABASE CLONEPDB FROM SOURCEPDB FILE_NAME_CONVERT = ('/u01/oradata/CDB/SOURCEPDB/', '/u01/oradata/CDB/CLONEPDB/');. To clone a local PDB, you use CREATE PLUGGABLE DATABASE ... FROM ... FILE_NAME_CONVERT. The FILE_NAME_CONVERT clause is necessary to redirect the data files to a new location. The other options either use incorrect syntax or attempt remote cloning. This command creates a full clone of the source PDB.

Answer

CREATE PLUGGABLE DATABASE CLONEPDB FROM SOURCEPDB;

Answer

CREATE PLUGGABLE DATABASE CLONEPDB FROM SOURCEPDB@link;

Answer

CREATE PLUGGABLE DATABASE CLONEPDB AS CLONE OF SOURCEPDB;

Question 9

Which view provides information about the open status of all PDBs in a CDB?

Accepted Answer

V$PDBS. V$PDBS provides the current status of each PDB in the container database.

Answer

V$INSTANCE

Answer

V$CONTAINERS

Answer

V$DATABASE

Answer

DBA_PDBS

Question 10

You need to migrate a non-CDB to a PDB in an existing CDB. Which package should you use to check for compatibility issues before starting the migration?

Accepted Answer

DBMS_PDB.CHECK_PLUG_COMPATIBILITY. DBMS_PDB.CHECK_PLUG_COMPATIBILITY is the standard procedure for pre-migration validation.

Answer

DBMS_PDB_MIGRATE

Answer

DBMS_METADATA.CHECK

Answer

DBMS_CDB_UPGRADE

Question 11

You need to migrate a non-CDB database to a PDB in a 23ai CDB. Which utility is the recommended tool to assess compatibility before migration?

Accepted Answer

DBMS_PDB.CHECK_PLUG_COMPATIBILITY. DBMS_PDB.CHECK_PLUG_COMPATIBILITY is the standard PL/SQL procedure to identify potential issues before plugging a non-CDB into a CDB.

Answer

RMAN CONVERT

Answer

DBUA

Answer

SQL Developer

Answer

Data Pump

Question 12

What is the purpose of the 'Seed' PDB (PDB$SEED)?

Accepted Answer

To act as a template for new PDBs. PDB$SEED is the template for creating new PDBs.

Answer

To store undo data

Answer

To hold CDB diagnostic logs

Answer

To store temporary data

Question 13

Which command is used to move a PDB from one CDB to another without using Data Pump?

Accepted Answer

ALTER PLUGGABLE DATABASE UNPLUG. The unplug/plug method using an XML metadata file is the standard for PDB transport.

Answer

CREATE PDB AS CLONE

Answer

DBMS_PDB.COPY

Answer

MOVE PLUGGABLE DATABASE

Question 14

What happens when you execute 'ALTER PLUGGABLE DATABASE ALL OPEN'?

Accepted Answer

Opens all PDBs in read-write mode. All PDBs in the CDB are opened in READ WRITE mode.

Answer

Opens only PDB$SEED

Answer

Opens all PDBs in read-only mode

Answer

Starts the CDB instance

Question 15

What is the default behavior when shutting down a CDB instance?

Accepted Answer

Closes all PDBs, then the CDB. The SHUTDOWN command closes all PDBs before the CDB.

Answer

Leaves PDBs open

Answer

Only closes the CDB root

Answer

Forces immediate abort