OCP Practice Test 21 — 15 Questions

Question 1

What is the purpose of the 'ASH' report?

Accepted Answer

To analyze short-term performance. ASH reports analyze transient problems by looking at recent active session history.

Answer

To backup the database

Answer

To analyze long-term trends

Answer

To manage user accounts

Question 2

You need to monitor wait events for a specific PDB. Which view is most appropriate?

Accepted Answer

V$SESSION. V$SESSION filtered by CON_ID allows viewing PDB-specific sessions.

Answer

V$PDB_WAIT

Answer

V$SYSTEM_EVENT

Answer

DBA_WAIT_EVENTS

Question 3

Which TWO views are used to check for plug-in compatibility?

Accepted Answer

V$PDB_COMPATIBILITY. PDB_PLUG_IN_VIOLATIONS and DBMS_PDB.CHECK_PLUG_COMPATIBILITY are standard.

Answer

V$PDB_STATUS

Answer

DBA_PDB_ERRORS

Answer

DBA_OBJECTS

Question 4

What is the result of setting STATISTICS_LEVEL to 'BASIC'?

Accepted Answer

It disables AWR and ADDM. Setting it to BASIC disables many diagnostic features, including AWR and ADDM.

Answer

It increases CPU overhead

Answer

It enables SQL Tuning Advisor

Answer

It enables all features

Question 5

What is the primary benefit of using a SQL Profile?

Accepted Answer

They improve the accuracy of the optimizer. SQL Profiles improve the optimizer's choices by providing better selectivity and cardinality estimates.

Answer

They fix the execution plan forever

Answer

They speed up physical I/O

Answer

They automatically gather new statistics

Question 6

An administrator needs to identify the top wait events causing performance degradation in the database over the last hour. Which tool provides the most granular, session-level view of these wait events?

Accepted Answer

Active Session History (ASH). ASH provides real-time, session-level performance data, making it the ideal tool for analyzing short-term, granular performance spikes.

Answer

SQL Tuning Advisor

Answer

Automatic Database Diagnostic Monitor (ADDM)

Answer

Automatic Workload Repository (AWR)

Question 7

Which TWO types of reports are most useful for diagnosing long-term database performance trends?

Accepted Answer

AWR Report. AWR reports and ADDM reports are standard tools for analyzing performance trends over extended periods (hours, days, or weeks).

Answer

V$SESSION_WAIT view

Answer

ASH Report

Answer

SQL Trace (tkprof)

Question 8

Which initialization parameter determines the maximum number of PDBs allowed in a CDB?

Accepted Answer

MAX_PDB_CONTAINERS. MAX_PDB_CONTAINERS defines the hard limit for PDBs in a CDB.

Answer

DB_FILES

Answer

PDB_LIMIT

Answer

CONTAINERS_MAX

Question 9

Which component is responsible for managing background processes across all containers in a CDB?

Accepted Answer

CDB Instance. The instance (CDB root) manages background processes for all containers.

Answer

Shared Service Layer

Answer

Global Process Manager

Answer

PDB Instance

Question 10

Which THREE characteristics are unique to PDBs?

Accepted Answer

Dedicated local users. PDBs have their own datafiles, their own users, and their own services.

Answer

Shared redo logs

Answer

Shared background processes

Question 11

You want to enforce password complexity in 23ai using a profile. Which clause is used to reference a custom verification function?

Accepted Answer

PASSWORD_VERIFY_FUNCTION. The PASSWORD_VERIFY_FUNCTION clause in the CREATE PROFILE statement allows for custom verification logic.

Answer

FAILED_LOGIN_ATTEMPTS

Answer

PASSWORD_LOCK_TIME

Answer

PASSWORD_LIFE_TIME

Question 12

An application is experiencing high library cache lock contention. Which view is best suited to investigate this specific wait event?

Accepted Answer

V$SESSION_WAIT. V$SESSION_WAIT shows details about wait events for active sessions.

Answer

V$PARAMETER

Answer

V$SQL

Answer

V$LOCK

Question 13

When using SQL Tuning Advisor, what is a 'SQL Tuning Set' (STS)?

Accepted Answer

A container for SQL statements and their metadata. An STS is a collection of SQL statements with their associated execution context.

Answer

A backup set of the database

Answer

A list of database users

Answer

A set of database indexes

Question 14

Which THREE steps are involved in upgrading a PDB?

Accepted Answer

Check PDB_PLUG_IN_VIOLATIONS. Run the upgrade script, compile invalid objects, and check for errors.

Answer

Restart the CDB

Answer

Recreate all users

Question 15

Which view should you query to verify the encryption status of tablespaces in 23ai?

Accepted Answer

V$ENCRYPTED_TABLESPACES. V$ENCRYPTED_TABLESPACES shows the encryption status of all tablespaces in the database.

Answer

DBA_ENCRYPTED_COLUMNS

Answer

DBA_ENCRYPTION_KEYS

Answer

DBA_TABLESPACES

Answer

V$WALLET