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………… controls the interaction among the concurrent transactions, to ensure the c

ID: 3803192 • Letter: #

Question

………… 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

a.

Concurrency-control manager

b.

Transaction-management component

c.

Transaction manager

d.

Transection

Explanation / Answer

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

Ans)


a.

Concurrency-control manager

…………. 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

b.

Storage manager

Every DBMS abstraction is a combination of


a.

Physical level & Logical level

One of the candidate keys is selected to be the:

a.

Primary key

An attribute is a(n):

c.

column of a table

Aggregate functions simply _________ null values

4.

ignore

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

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

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

a.

Entity set


a.

Concurrency-control manager