Explore topic-wise MCQs in Database.

This section includes 59 Mcqs, each offering curated multiple-choice questions to sharpen your Database knowledge and support exam preparation. Choose a topic below to get started.

1.

Which among the following tags belong to Data Manipulation language?

A. UPDATE
B. ALTER
C. MODIFY
D. All of the mentioned
Answer» E.
2.

Select the sequence for how the query mechanism works?

A. Authentication-> DDL->DML->query optimizer->output
B. DDL->DML->query optimizer-> Authentication->output
C. DML->query optimizer-> Authentication-> DDL-> output
D. All of the mentioned
Answer» B. DDL->DML->query optimizer-> Authentication->output
3.

The users responsible for query processing in database system are ___________

A. Native users
B. Application programmers
C. Sophisticated users
D. Specialized users
Answer» D. Specialized users
4.

What is the meaning of “EMPTY SET” in the following MySQL command?

A. No values
B. Error
C. Access denied
D. None of the mentioned
Answer» B. Error
5.

Which of the following are the valid “database datatypes” in Mysql?

A. Numerical
B. Temporal
C. Text
D. All of the mentioned
Answer» E.
6.

How many of the following implement the default scheduling property of MySQL?

A. 0
B. 1
C. 2
D. 3
Answer» E.
7.

TO enable the compressed client/server protocol the option is _________________

A. –enable
B. –compress
C. –reduce
D. –restrict
Answer» C. –reduce
8.

Which option turns on the –extended-insert?

A. –opt
B. –opti
C. –op
D. –optimize
Answer» B. –opti
9.

What are the results of the following SQL commands if col is an integer column?

A. same
B. different
C. 1 is an error
D. 2 is an error
Answer» B. different
10.

Which of these take more space?

A. variable length
B. same
C. fixed length
D. indeterminate
Answer» D. indeterminate
11.

Which of the following WHERE clauses are faster?

A. 1
B. 2
C. same speed
D. dependent on operating system
Answer» C. same speed
12.

Avoiding NULL in columns may make queries simpler.

A. True
B. False
C. May be True or False
D. Can't say
Answer» B. False
13.

Which clause is used to “group rows together by common columns values”?

A. SELECT
B. GROUP BY
C. FROM
D. WHERE
Answer» C. FROM
14.

To convert an int to string, the function is _________________

A. INET_ATON()
B. INET_NTOA()
C. INET_ITOS()
D. INET_STOI()
Answer» C. INET_ITOS()
15.

Which clause is used to “Filters out unwanted data”?

A. FROM
B. WHERE
C. SELECT
D. ORDER BY
Answer» C. SELECT
16.

Which table is preferred when there are many updates?

A. MyISAM
B. InnoDB
C. MEMORY
D. MERGE
Answer» C. MEMORY
17.

“MODIFY” is used with which “Query clause”?

A. ALTER
B. FROM
C. WHERE
D. ORDER BY
Answer» B. FROM
18.

The number of tables for which DELAYED works is _________________

A. 1
B. 2
C. 3
D. 4
Answer» E.
19.

To maintain performance of tables having variable length rows, which statement is used?

A. MAINTAIN TABLE
B. BALANCE TABLE
C. ADJUST TABLE
D. OPTIMIZE TABLE
Answer» E.
20.

IP numbers can be represented as _________________

A. both integers and a string
B. a string but not integers
C. integers but not a string
D. neither a string nor integers
Answer» B. a string but not integers
21.

The optimizer_prune_level is set by default.

A. True
B. False
C. May be True or False
D. Can't say
Answer» B. False
22.

Which of these can be used to generate hash values?

A. MS5()
B. MA5()
C. MF5()
D. MD5()
Answer» E.
23.

To reactivate indexes the command used is _________________

A. DISABLE KEYS
B. DISABLE INDEXES
C. ENABLE KEYS
D. ENABLE INDEXES
Answer» D. ENABLE INDEXES
24.

Which clause is used to “Identifies table from which to draw table and how the table should be joined”?

A. FROM
B. SELECT
C. ORDER By
D. WHERE
Answer» B. SELECT
25.

To minimize disk I/O, which of these should be chosen?

A. CHAR
B. VARCHAR
C. CHAR & VARCHAR
D. Either CHAR or VARCHAR
Answer» C. CHAR & VARCHAR
26.

Find the odd one out in terms of scheduling policies.

A. MyISAM
B. InnoDB
C. MEMORY
D. MERGE
Answer» C. MEMORY
27.

Which Key is used to link two tables in Mysql?

A. Primary Key
B. Foreign Key
C. Both Primary and Foreign Key
D. None of the mentioned
Answer» C. Both Primary and Foreign Key
28.

Calculations involving numbers are faster than those involving string.

A. True
B. False
C. May be True or False
D. Can't say
Answer» B. False
29.

Which clause is used to “sort the rows of the final result set by one or more columns”?

A. HAVING
B. ORDER BY
C. WHERE
D. FROM
Answer» C. WHERE
30.

What jobs “Query Optimizer” perform in Mysql?

A. Determine the efficient way to execute a query
B. Syntax errors
C. Permissions
D. All of the mentioned
Answer» B. Syntax errors
31.

Which system variable tells how far into the rest of each incomplete plan the optimizer should look to evaluate whether it should be expanded further?

A. optimizer_prune_level
B. optimizer_search_depth
C. optimizer_search
D. optimizer_prune
Answer» C. optimizer_search
32.

Which clause is used to “filter out unwanted Groups”?

A. HAVING
B. FROM
C. WHERE
D. SELECT
Answer» B. FROM
33.

The number of tables among the following for which HIGH_PRIORITY have an effect are _________________

A. 0
B. 1
C. 2
D. 3
Answer» E.
34.

Which among the following is not a “query clause”?

A. WHERE
B. MODIFY
C. ALTER
D. FROM
Answer» B. MODIFY
35.

Which system variable tells the optimizer to skip certain plans based on estimates of the number of rows accessed for each table?

A. optimizer_prune_level
B. optimizer_search_depth
C. optimizer_search
D. optimizer_prune
Answer» B. optimizer_search_depth
36.

Query Mechanism performs the following functions?

A. Syntax correction
B. Checking permission for executing the query
C. Checking permission for accessing the desired data
D. All of the mentioned
Answer» E.
37.

The use of table level locks is always useful in MyISAM tables.

A. True
B. False
C. May be True or False
D. Can't say
Answer» C. May be True or False
38.

Installing more memory into the machine enables to configure larger values for cache server.

A. True
B. False
C. May be True or False
D. Can't say
Answer» B. False
39.

The option which delays index flushing for slave server is _________________

A. –delay-write-key=ALL
B. –delay-key-write=ALL
C. –key-write-delay=NONE
D. –key-delay-write=NONE
Answer» C. –key-write-delay=NONE
40.

Which clause is used to determine “which column to include in the query sets”?

A. SELECT
B. FROM
C. WHERE
D. ORDER BY
Answer» B. FROM
41.

Which line of the following statements will produce error?

A. SELECT * FROM person WHERE person_id=1;
B. SELECT pname FROM person;
C. SELECT pname, lname, person_id FROM person;
D. None of the mentioned
Answer» E.
42.

Which of these columns are faster?

A. same
B. variable length
C. fixed length
D. indeterminate
Answer» D. indeterminate
43.

To convert a string to an int, the function is _________________

A. INET_ATON()
B. INET_NTOA()
C. INET_ITOS()
D. INET_STOI()
Answer» B. INET_NTOA()
44.

To how many of these does the LOW_PRIORITY modifier apply to?

A. 1
B. 2
C. 3
D. 4
Answer» E.
45.

For a table having 4 columns, the number of columns to which hash function is applied when using hash indexes is __________

A. 1
B. 2
C. 3
D. 4
Answer» E.
46.

The slow query log can be used to identify queries that may be performing badly.

A. True
B. False
C. May be True or False
D. Can't say
Answer» B. False
47.

If a column contains 7 values and 6 distinct values, the cardinality is __________

A. 7
B. 6
C. 13
D. 1
Answer» C. 13
48.

Suppose tbl_1 is a table consisting of 8 rows and tbl_2 is a table consisting of 6 rows, the number of combinations through which the search is performed is __________

A. 14
B. 2
C. 1
D. 48
Answer» E.
49.

The slow query log is written as __________

A. numbers
B. text
C. image
D. graph
Answer» C. image
50.

IN_________________THE_MANAGEMENT_OF_THE_PASSWORD_FOR_THE_ACCOUNT_CAN_BE_HANDLED_OUTSIDE_OF_ORACLE_SUCH_AS_OPERATING_SYSTEM.?$

A. Database Authentication
B. Operating System Authentication
C. Internal Authentication
D. External Authentication
Answer» C. Internal Authentication