Explore topic-wise MCQs in Database.

This section includes 39 Mcqs, each offering curated multiple-choice questions to sharpen your Database knowledge and support exam preparation. Choose a topic below to get started.

1.

Oracle directly supports the definition of surrogate keys.~!

A. True
B. False
Answer» C.
2.

Oracle maintains a System Change Number (SCN) which is a database-wide value that is incremented by Oracle whenever database changes are made.~!

A. True
B. False
Answer» B. False
3.

Oracle will let you define Notepad as your default editor, and whenever you type NOTEPAD, SQL*Plus will invoke Notepad.~!

A. True
B. False
Answer» C.
4.

You can check on the status of tables with the DESCRIBE or DESC command.%!

A. True
B. False
Answer» B. False
5.

The left-leaning slash tells Oracle to execute whatever statement is in the buffer.%!

A. True
B. False
Answer» C.
6.

Sequences guarantee valid surrogate key values.%!

A. True
B. False
Answer» C.
7.

When you type Start FILENAME, the statement in your file will be executed automatically.%!

A. True
B. False
Answer» B. False
8.

The default extension for SQL*Plus is .sql.%!

A. True
B. False
Answer» B. False
9.

Oracle does NOT support a CASCADE UPDATE constraint.%!

A. True
B. False
Answer» B. False
10.

SQL*Plus is a text editor.%!

A. True
B. False
Answer» B. False
11.

Money is defined in Oracle with the Currency data type.%!

A. True
B. False
Answer» C.
12.

Oracle allows the ORDER BY clause in view definitions.%!

A. True
B. False
Answer» B. False
13.

The semicolon terminates a SQL statement (and executes it).%!

A. True
B. False
Answer» B. False
14.

Indexes are created to enforce uniqueness on columns and to enable fast retrieval by column values.%!

A. True
B. False
Answer» B. False
15.

When you type into SQL*Plus and press enter, the statement will be finished and executed.%!

A. True
B. False
Answer» C.
16.

Which of the following is not true about indexes?%!

A. Indexes are created to enforce uniqueness on columns.
B. Indexes are created to enable fast retrieval by column values.
C. Columns that are frequently used with equal conditions in WHERE clauses are good candidates for indexes.
D. Indexes are created with the ALTER TABLE command.
Answer» E.
17.

Which of the following is not true about modifying table columns?%!

A. You can drop a column at any time.
B. You can add a column at any time as long as it is a NULL column.
C. You can increase the number of characters in character columns or the number of digits in numeric columns
D. You cannot increase or decrease the number of decimal places.
Answer» E.
18.

To see the contents of the SQL*Plus buffer, type:%!

A. CONTENTS
B. BUFFER
C. CURRENT
D. LIST
Answer» E.
19.

What is the type of Oracle backup in which all uncommitted changes have been removed from the datafiles?%!

A. Full backup
B. Consistent backup
C. Inconsistent backup
D. Differential backup
Answer» C. Inconsistent backup
20.

*$_Which of the following is not true about modifying table columns??

A. You can drop a column at any time.
B. You can add a column at any time as long as it is a NULL column.
C. You can increase the number of characters in character columns or the number of digits in numeric columns
D. You cannot increase or decrease the number of decimal places.
Answer» E.
21.

*$_To see the contents of the SQL*Plus buffer, type:?

A. CONTENTS
B. BUFFER
C. CURRENT
D. LIST
Answer» E.
22.

*$_What is the type of Oracle backup in which all uncommitted changes have been removed from the datafiles??

A. Full backup
B. Consistent backup
C. Inconsistent backup
D. Differential backup
Answer» C. Inconsistent backup
23.

*$_Which of the following is not true about indexes??

A. Indexes are created to enforce uniqueness on columns.
B. Indexes are created to enable fast retrieval by column values.
C. Columns that are frequently used with equal conditions in WHERE clauses are good candidates for indexes.
D. Indexes are created with the ALTER TABLE command.
Answer» E.
24.

%_After a table has been created, its structure can be modified using the SQL command:_%

A. UPDATE TABLE [TableName].
B. MODIFY TABLE [TableName].
C. ALTER TABLE [TableName].
D. CHANGE TABLE [TableName].
Answer» D. CHANGE TABLE [TableName].
25.

%_To obtain the structure of an Oracle table, the command to use is:_%

A. STRUCTURE [TableName].
B. DESCRIBE [TableName].
C. DESCRIBE STRUCTURE [TableName].
D. DESC TABLE [TableName].
Answer» C. DESCRIBE STRUCTURE [TableName].
26.

%_Which SQL phrase is not supported by Oracle?_%

A. ON DELETE CASCADE
B. ON UPDATE CASCADE
C. CREATE SEQUENCE [SequenceName]
D. DROP SEQUENCE [SequenceName]
Answer» C. CREATE SEQUENCE [SequenceName]
27.

_ In creating a procedure, you may get a message if you have compile errors. Which of the following is true?$?

A. The line numbers reported match the line numbers you see in your text editor.
B. SQL*Plus will automatically show the errors to you.
C. To see the errors, enter SHOW ERRORS in SQL*Plus.
D. If there are no syntax errors, you will receive the message "NO ERRORS."
Answer» D. If there are no syntax errors, you will receive the message "NO ERRORS."
28.

_Which of the following is NOT an Oracle-supported trigger?$?

A. BEFORE
B. DURING
C. AFTER
D. INSTEAD OF
Answer» C. AFTER
29.

_An Oracle System Change Number (SCN):$?

A. is a value that is incremented whenever a dirty read occurs.
B. is incremented whenever a deadlock occurs.
C. is a value that keeps track of explicit locks.
D. is a value that is incremented whenever database changes are made.
Answer» E.
30.

_When using SQL*Plus, Oracle commands, column names, table names and all other database elements:$?

A. are case insensitive.
B. are case sensitive.
C. must always be in lower case.
D. must always be in upper case.
Answer» B. are case sensitive.
31.

_Which prefixes are available to Oracle triggers?$?

A. :new only
B. :old only
C. Both :new and :old
D. Neither :new nor :old
Answer» D. Neither :new nor :old
32.

Which statement about sequences is not true?$?

A. A sequence is an object that generates a sequential series of unique numbers.
B. Sequences are most often used to provide values for surrogate keys.
C. NextVal and CurrVal are both sequence methods.
D. Sequences guarantee valid surrogate key values.
Answer» E.
33.

SQL*Plus will finish the statement and execute it when the user types in this:$?

A. A left slash ( ) followed by [Enter].
B. A colon ( : ) followed by [Enter].
C. A semicolon ( ; ) followed by [Enter].
D. A period ( . ) followed by [Enter].
Answer» D. A period ( . ) followed by [Enter].
34.

The default extension for an Oracle SQL*Plus file is:$?

A. .txt
B. .pls
C. .ora
D. .sql
Answer» E.
35.

What Oracle backup and recover file contains user and system data?$?

A. Control file
B. Datafile
C. OnLine ReDo file
D. Offline ReDo file
Answer» C. OnLine ReDo file
36.

SQL*Plus will finish the statement and execute it when the user types in this:?

A. A left slash ( ) followed by [Enter].
B. A colon ( : ) followed by [Enter].
C. A semicolon ( ; ) followed by [Enter].
D. A period ( . ) followed by [Enter].
Answer» D. A period ( . ) followed by [Enter].
37.

The default extension for an Oracle SQL*Plus file is:?

A. .txt
B. .pls
C. .ora
D. .sql
Answer» E.
38.

What Oracle backup and recover file contains user and system data??

A. Control file
B. Datafile
C. OnLine ReDo file
D. Offline ReDo file
Answer» C. OnLine ReDo file
39.

Which statement about sequences is not true??

A. A sequence is an object that generates a sequential series of unique numbers.
B. Sequences are most often used to provide values for surrogate keys.
C. NextVal and CurrVal are both sequence methods.
D. Sequences guarantee valid surrogate key values.
Answer» E.