Oracle Database Multiple Choice Questions (MCQs) and Answers

Listener is not running

Incorrect connection string

User lacks privileges

Database is offline

Incorrect tnsnames.ora configuration

Listener not running

Database not started

Missing privileges

A single variable

A group of elements of the same type

A database table

A SQL query

VARRAYs are unbounded; nested tables are bounded

Nested tables maintain order; VARRAYs do not

VARRAYs have a fixed size; nested tables do not

Nested tables are faster than VARRAYs

To handle single-row queries

To fetch multiple rows into a collection

To speed up DML operations

To update indexes

DECLARE my_varray VARRAY(5) OF NUMBER; BEGIN ...

DECLARE my_varray ARRAY[5] OF NUMBER; BEGIN ...

DECLARE VARRAY my_varray(5) AS NUMBER; BEGIN ...

DECLARE my_varray VARRAY(5) IS NUMBER; BEGIN ...

DECLARE my_collection TABLE OF NUMBER; BULK COLLECT INTO my_collection ...

DECLARE my_collection TABLE IS NUMBER; BEGIN BULK COLLECT ...

DECLARE TYPE my_collection IS TABLE OF NUMBER; BEGIN SELECT * BULK COLLECT INTO my_collection ...

DECLARE TABLE my_collection OF NUMBER; BEGIN BULK SELECT ...

Collection type mismatch

Missing INTO clause

Invalid syntax

Null values in the table

Collection is declared but not initialized

Invalid loop construct

Incorrect data type

Invalid bulk operation

To improve data security

To provide high availability and scalability

To optimize SQL queries

To backup data

By using redo logs

By using cache fusion

By using control files

By using archive logs

Nodes are physical servers; instances are memory and processes

Nodes are virtual; instances are physical

Nodes and instances are the same

Instances manage storage; nodes manage connections

SELECT INSTANCE_NAME, STATUS FROM V$INSTANCE;

SELECT NODE_NAME, STATUS FROM V$NODE_STATUS;

SELECT * FROM GV$INSTANCE_STATUS;

SELECT INSTANCE_STATUS FROM GV$INSTANCE;

SELECT * FROM GV$LOAD_BALANCING;

SELECT INSTANCE_NAME, LOAD FROM GV$LOAD_BALANCING_STATUS;

SELECT INSTANCE_NAME, LOAD FROM GV$SESSION;

SELECT INSTANCE_NAME, SESSIONS_ACTIVE FROM GV$INSTANCE;

Cluster synchronization failure

Instance corruption

Redo log missing

Datafile is corrupted

Incorrect TNS configuration

Listener not running

Node is down

Database is offline

To improve query performance

To provide disaster recovery and data protection

To manage user privileges

To optimize storage

Physical standby is a block-for-block copy; logical standby allows data transformations

Physical standby stores only redo logs; logical standby stores only transactions

Physical standby is slower

Logical standby does not support updates

To manage user sessions

To automate configuration and monitoring

To create backups

To optimize queries

ALTER SYSTEM SET DG_BROKER_START=TRUE;

START DG BROKER;

ENABLE DATAGUARD BROKER;

ALTER DATABASE ENABLE DG_BROKER;

ALTER DATABASE SWITCH TO STANDBY;

ALTER DATABASE CONVERT TO STANDBY;

ALTER DATABASE SWITCHOVER TO STANDBY;

SWITCH DATABASE ROLE TO STANDBY;

Redo logs not applied

Standby database not synchronized

Network connection issue

All of the above

Network issue

Redo logs corrupted

Primary database is down

Standby database is corrupted

To explore practical applications

To improve database security

To study query performance

To optimize backups

By using parallel queries

By indexing all columns

By enabling Data Pump

By disabling constraints

To improve query performance and manage large datasets

To create database backups

To enhance user privileges

To secure the database

CREATE TABLE sales (id NUMBER, sales_date DATE, amount NUMBER) PARTITION BY RANGE (sales_date) (PARTITION p1 VALUES LESS THAN (TO_DATE('2023-01-01','YYYY-MM-DD')), PARTITION p2 VALUES LESS THAN (MAXVALUE));

CREATE TABLE sales PARTITION BY RANGE ON sales_date;

CREATE TABLE sales PARTITION BY RANGE (sales_date) PARTITION LESS_THAN ('2023-01-01');

PARTITION TABLE sales (sales_date RANGE) LESS_THAN ('2023-01-01');

CREATE MATERIALIZED VIEW mv_sales AS SELECT product_id, SUM(amount) FROM sales GROUP BY product_id;

CREATE VIEW mv_sales AS SELECT product_id, SUM(amount) FROM sales;

CREATE TABLE mv_sales AS SELECT product_id, SUM(amount) FROM sales GROUP BY product_id;

MATERIALIZE VIEW mv_sales SELECT product_id, SUM(amount) FROM sales;

Missing refresh clause

Corrupted base table

Incorrect query syntax

Database in read-only mode

Missing index on partition key

Incorrect partition strategy

Outdated statistics

All of the above