Home Random Page


CATEGORIES:

BiologyChemistryConstructionCultureEcologyEconomyElectronicsFinanceGeographyHistoryInformaticsLawMathematicsMechanicsMedicineOtherPedagogyPhilosophyPhysicsPolicyPsychologySociologySportTourism






B. implies the absence of transitive functional dependencies

C. Normalization is a process that cannot be undone

d. Normalization is performed as a series of steps

 

 

7. Degree of a relation is a

a. number of keys in the relation

b. number of tuples in the relation

c. number of rows in the relation

D. number of attributes in the relation

 

 

8. What is a projection in the relational algebra?

a. Projection defines a relation that contains only those tuples that satisfy the specified condition

B. Projection defines a relation that contains the values of specified attributes

c. Projection defines a relation consisting of the set of all tuples that are in both R and S operand relations

d. Projection defines a relation that contains all the tuples of R, or S, or both R and S operand relations

 

 

9. An attribute with the value calculated based on the values of other attributes is called

a. derived

b. composite

c. multi-valued

d. default

 

 

10. Which of the following statements is not true?

a. A DBMS is a set of software tools that control access, organize, store, manage, retrieve and maintain data in a database

b. Alternate key is a candidate key which is not selected as primary key

c. Cardinality of a relation is a number of tuples in the relation

d. An attribute that cannon be further subdivided into smaller components is called single-valued attribute

 

1. Physical database design involves?

a. Identifying entities, relations, attributes and drawing ER-diagram

b. Deriving relations and performing normalization

c. Creating tables and inserting data into the tables

d. Deriving data from tables. The data corresponds to some condition

 

 

2. What is an alternate key?

a. Alternate key is a candidate key which is not selected as primary key

b. Alternate key is any attribute which can be selected as primary key

c. Alternate key is a set of attributes, each attribute with a unique value

d. Alternate key is another name for primary key

 

 

3. Which of the following statements about normalization is NOT true?

a. Normalization is performed within the conceptual database design

b. Normalization is a process of decomposing complex relations

c. Normalization is performed as a series of steps

d. Normalization is a process that can be undone

 

 

4. Multiplicity is a

a. number of occurrences of a particular value within a relation

b. number of occurrences of entity types within a particular relationship

c. number of cells in the relation

d. number of attributes in the relation

 

 

5. What is a union in the relational algebra?

a. Union defines a relation that contains only those tuples that satisfy the specified condition

b. Union defines a relation that contains all the tuples of R operand relation but not the tuples of S operand relation

c. Union defines a relation consisting of the set of all tuples that are in both R and S operand relations



d. Union defines a relation that contains all the tuples of R, or S, or both R and S operand relations

 

 

6. The Third Normal Form

a. implies the absence of repeating groups of data

b. implies the absence of transitive functional dependencies

c. implies that non-key attributes fully functionally dependent on the primary key

d. implies that non-key attributes fully functionally dependent on the composite primary key

 

 

7. What is a Database Management System?


Date: 2016-01-14; view: 498


<== previous page | next page ==>
Why we are removing a figure from our indicators page | There can be more than one condition in a query
doclecture.net - lectures - 2014-2019 year. Copyright infringement or personal data (0.002 sec.)