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databases Online Quiz - 135

Description: databases Online Quiz - 135
Number of Questions: 20
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Tags: databases
Attempted 0/20 Correct 0 Score 0

Which of the following objects could not be modified using ALTER statement

  1. Tablespace

  2. Sequence

  3. Views

  4. Index


Correct Option: C

Pick the odd one out

  1. AVG

  2. SUM

  3. STDDEV

  4. ABS


Correct Option: D

Which of the following contains Database Descriptors(DBD)

  1. DB2 Directory

  2. DB2 Catalog

  3. Optimizer

  4. Data Manager


Correct Option: A

Which table gives access path information for a plan/query when EXPLAIN command is used

  1. DSN_STATEMNT_TABLE

  2. PLAN_TABLE

  3. SYSPLAN

  4. SYSPACKAGE


Correct Option: B

Which of the following functions can be used to determine whether a column value is NULL

  1. SUBSTR

  2. VALUE

  3. COALESCE

  4. NULLIF


Correct Option: B,C

Which of the following groups allows its members to connect to a 9i database using the SYSDBA privilege?

  1. 9iDBA

  2. OSADM

  3. OSDBA

  4. OSOPER


Correct Option: C
  1. CREATE SPFILE

  2. CREATE DATABASE

  3. ALTER DATABASE OPEN

  4. STARTUP


Correct Option: B

According to the Oracle recommended prioritized approach for designing, implementing, and maintaining an Oracle Database, which of the following is the task for the DBA to perform before tuning the database?

  1. Install the Oracle Software

  2. Plan the Database

  3. Implement the Database Design

  4. Back Up the Fully Functional Database


Correct Option: D

According to the Oracle recommended prioritized approach for designing, implementing, and maintaining an Oracle Database, which of the following is the first task for the DBA to perform?

  1. Install the Oracle Software

  2. Evaluate the Database Server Hardware

  3. Implement the Database Design

  4. Plan the Database


Correct Option: B

The initial password of CHANGE_ON_INSTALL is used by which of the following user accounts?

  1. SYSTEM

  2. SYS

  3. SYSOPER

  4. MANAGER


Correct Option: B

What environment variable can have direct influence towards the output of the date command?

  1. TZ

  2. TMP

  3. TMPDIR

  4. SHLIB_PATH


Correct Option: A

Which of the following are the functions of the oraenv script

  1. It provides a security scan against all user accounts

  2. It provides a SID scan against all rows

  3. It provides a central means of updating all user accounts

  4. It provides a mechanism for switching between Oracle9i databases with ease


Correct Option: C

A directory name can be a valid value for which of the following parameters?

  1. DB_CACHE_SIZE

  2. DB_FILES

  3. BACKGROUND_DUMP_DEST

  4. DB_BLOCK_SIZE


Correct Option: C

How do you change the block size specified by DB_BLOCK_SIZE?

  1. modify the parameter, backup the init file and the database, and restart the instance

  2. modify the parameter and restart the instance

  3. re-create the database

  4. modify the parameter, backup the init file and restart the instance


Correct Option: C

What is used in Oracle 9i to represent the value of the ORACLE_HOME environment variable?

  1. #

  2. &

  3. !

  4. ?


Correct Option: D

Abbreviation of SQL

  1. Sequel query language

  2. Structured query language

  3. Shortened query language

  4. Simplified query language


Correct Option: C

What is necessary in the SQL query when we are using aggregate functions?

  1. Group by

  2. Order by

  3. Where

  4. Update


Correct Option: D

Which is NOT the single-row functions??

  1. sinh()

  2. to_number()

  3. sqrt()

  4. round()


Correct Option: B

What is the default character for specifying substitution variables in select statements?

  1. Ellipses

  2. Quotation marks

  3. Ampersand

  4. Asterisk


Correct Option: C

AI Explanation

To answer this question, you need to understand the concept of substitution variables in SQL.

Substitution variables are used in SQL to prompt the user for input during the execution of a query. They allow you to dynamically substitute values into a query at runtime.

The default character for specifying substitution variables in select statements is the ampersand (&) symbol. When the SQL statement is executed, the user is prompted to enter a value for the substitution variable.

Let's go through each option to understand why it is correct or incorrect:

Option A) Ellipses - This option is incorrect because ellipses (...) are not used for specifying substitution variables in select statements.

Option B) Quotation marks - This option is incorrect because quotation marks (") are not used for specifying substitution variables in select statements.

Option C) Ampersand - This option is correct because the ampersand (&) symbol is the default character for specifying substitution variables in select statements.

Option D) Asterisk - This option is incorrect because the asterisk (*) is not used for specifying substitution variables in select statements.

The correct answer is Option C) Ampersand. This option is correct because the ampersand (&) symbol is the default character for specifying substitution variables in select statements.

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