1) Which of the following does not improve database write times?
a) Normalising data to reduce amount of data to be written
b) Using transactions for every database operation
c) Removing unnecessary constraints
d) Using a hard disk with faster write speeds
Answer(s) : b) Using transactions for every database operation
2) Which of the following will NOT help when a database begins to become too large to keep on one system
a) Setting up a slave database
b) Setting up daily database dump
c) Archiving data
d) Sharding database
Answer(s) : a) Setting up a slave database
b) Setting up daily database dump
3) In a typical master/slave database system
a) Writes can be made on the master
b) Writes can be made on the slave
c) Reads can be made on the slave
d) Reads can be made on the master
Answer(s) : a) Writes can be made on the master
c) Reads can be made on the slave
4) A SQL database view
a) Contains data not stored in the database tables
b) Is not computed using a SQL query
c) Is computed using a SQL query
d) Is a way to improve the read time of a table in a database
Answer(s) : c) Is computed using a SQL query
5) Which SQL statement isn’t used to update a database table schema?
a) UPDATE TABLE
b) ALTER TABLE
c) CHANGE TABLE
d) MODIFY TABLE
Answer(s) : (a) UPDATE TABLE (c) CHANGE TABLE (d) MODIFY TABLE
6) Database normalisation does not typically
a) Reduce data constraints
b) Reduce chances of data anomalies
c) Reduce database size
d) Reduce number of tables
Answer(s) : a) Reduce data constraints
d) Reduce number of tables
7) Which of the following are not SQL aggregate functions?
a) SELECT
b) AVG
c) JOIN
d) MIN
Answer(s) : a) SELECT
c) JOIN
8) A database index
a) Doesn’t increase database size
b) Decreases database size
c) Doesn’t affect database size
d) None of the above
Answer(s) : d) None of the above
9) Which of the following code will create an index named stu_sub on the columns roll_no and subject of the stu_subjects table?
a) create index stu_sub from stu_subjects(roll_no, subject);
b) create index stu_subjects on stu_sub(roll_no, subject);
c) create index stu_sub on stu_subjects(roll_no, subject);
d) create index stu_sub on stu_subject(roll_no, subject);
Answer(s) : c) create index stu_sub on stu_subjects(roll_no, subject);
10) For table EMPLOYEE
The query SELECT ID FROM CUSTOMERS WHERE SALARY > 5000 OR age < 25; will produce result
a) 6 7
b) 3 4 5 6 7
c) 1 2 3 4 5 6 7
d) None of the above
Answer(s) : b) 3 4 5 6 7
