In: Computer Science
Recall that a database has many types of users, each of whom may require a different view of the database. The database user responsible for creating database accounts in a DBMS like Oracle is called the:
Answer: a. The database administrator (DBA)
Explanation: In a database management system, the database administrator is responsible for locking and unlocking user accounts.
Which of the following can be an example of a multi-valued attribute in ER modeling of a database?
Answer: a. address
Explanation: An address consists of many atomic parts, thus it is a multivalued attribute.
One limitation of traditional file system, which runs programs with data, that is solved by using a database management system is:
Answer: a. Provision of data independence
Explanation: Changing files changes programs in a traditional file system.
In a database, integrity constraints must not be violated after
any database update. Given a database table with schema Customer
(Id, Fname, Lname, phone), which has a state having the two tuples
<1, ‘Mark’, ‘Adam’, ‘416-555-2233’> and
<2, ‘Pat’, ‘Moore’, ‘519-333-6161’>, what integrity
constraint is violated by inserting the following new tuple into
Customer
<1, NULL, ‘Hardy’, ‘226-222-1234’>.
Answer: c. Primary Key Integrity constraint
Explanation: Id 1 already exists and it is primary key so the value of primary key cant be repeated.