controls the interaction among the concurrent transactions, to ensure the consistency of the database.

	a.	Concurrency-control manager
	b.	Transaction-management component
	c.	Transaction manager
	d.	Transection

. is a program module that provides the interface between the low-level data stored in the database and the application programs and queries submitted to the system.

	a.	Transection
	b.	Storage manager
	c.	Transaction manager
	d.	SQL

Every DBMS abstraction is a combination of __________________

	a.	Physical level & Logical level
	b.	Physical level, logical view and View level
	c.	Logical level & View Level
	d.	Physical level & View level

One of the candidate keys is selected to be the:

	a.	Primary key
	b.	Super key
	c.	Foreign key

An attribute is a(n):

	a.	row of a table
	b.	Two-dimensional table.
	c.	column of a table

Aggregate functions simply _________ null values

	1.	take into account
	2.	reject
	3.	delete
	4.	ignore

Avg, min, max, sum and count are called _________ functions

	1.	algebra
	2.	normal
	3.	complex
	4.	aggregate

In Relational Algebra, the operation which only selects some of the attributes from a relation and neglects the remaining attributes is known as _________.

	a.	PROJECT operation
	b.	AND operation
	c.	TABLE operation

.. is a set of entities of the same type that share the same properties

	a.	Entity set
	b.	Attributes
	c.	relationship set