ITS_DATABSE #2

The terms "bitmap," "b-tree," and "hash" refer to which type of database structure?

• A. View

• B. Function

• C. Index

• D. Stored procedure

• E. Trigger Correct

Answer explanation

An index contains keys built from one or more columns in the table or view. These keys are stored in a structure (B-tree) that enables SQL Server to find the row or rows associated with the key values quickly and efficiently

One reason to add an index is to:

• A. Decrease storage space.

• B. Increase database security.

• C. Improve performance of select statements.

• D. Improve performance of insert statements. Correct

Answer explanation

Indexes are used to retrieve data from the database more quickly than otherwise.

• A. defragmentation

• B. normalization

• C. fragmentation

• D. denormalization

Answer explanation

In brief, normalization is a way of organizing the data in the database. Normalization entails organizing the columns and tables of a database to ensure that their dependencies are properly enforced by database integrity constraints.

You have a table that contains the following data.

Which database term is used to describe the relationship between ProductID and ProductCategory?

• A. Cohort

• B. Relationally dependent

• C. Deterministic

• D. Functionally dependent

• E. Compositional Correct

Answer explanation

Functional dependency is a constraint between two sets of attributes in a relation from a database. In other words, functional dependency is a constraint that describes the relationship between attributes in a relation.

Which key uniquely identifies a row in a table?

• A. foreiqn

• B. primary

• C. local

• D. superkey

Answer explanation

The PRIMARY KEY constraint uniquely identifies each record in a table. Primary keys must contain UNIQUE values, and cannot contain NULL values.

Which statement creates a composite key?

• A. Option A

• B. Option B

• C. Option C

• D. Option D

Answer explanation

A composite key is a combination of two or more columns in a table that can be used to uniquely identify each row in the table

At 3:00 P.M. (1500 hours), you create a backup of your database. At 4:00 P.M. (1600 hours), you create a table named Customer and import data into the table. At 5:00 P.M. (1700 hours), your server fails. You run a script to apply only the 3:00 P.M. backup to your database. What is the result of the script?

• A. The Customer table no longer exists.

• B. The Customer table is unaffected.

• C. The Customer table exists but has no data.

• D. The script fails.

In which situation do you need to perform a restore on a database?

• A. when data becomes corrupted in the database

• B. when you need to roll back a transaction

• C. when you encounter an error in your application

• D. when data needs to be deleted from the database

Which command should you use to give a user permission to read the data in a table?

• A. ALLOW SELECT

• B. LET READ

• C. PERMIT READ

• D. GRANT SELECT Correct

Answer explanation

SQL GRANT is a command used to provide access or privileges on the database objects to the users.

You need to enable a new employee to authenticate to your database. Which command should you use?

• A. ALLOW USER

• B. CREATE USER

• C. ADD USER

• D. INSERT USER

• E. ALTER USER