Database Tests with Answers

Tests on the topic: “Databases” with answers

The correct answer is marked with a + sign.

1. Databases are:

– a complex program aimed at recording incoming information

+ data sets under the control of management systems

– an infinite volume of data, constantly managed by a DBMS

2. The main difference between a relational database:

+ data is organized into relationships

– strictly tree-like structure

– presented in the form of graphs

3. The DB file extension is:

– .f2

+ .mdb, .db

– .mcs

4. The word Null in the database is used to indicate:

+ undefined values

– empty values

– zero

5. What is a tuple?

– a set of attributes

+ a set of pairs of attributes and their values

– data relationship diagram

6. The power of a relationship is:

– the number of branches in the graph system

– the order of data subordination in the tree structure of the database

+ number of tuples in relation

7. The main condition of comparable relations:

+ the same relationship pattern

– the exact number of comparable features

– the presence of quantitative characteristics

8. The projection operation is aimed at:

– overlaying data from one database on data from another database

+ data selection according to specified attributes

– comparison of databases based on similarity

9. Unlike user-defined data types, basic data types:

+ are present in the database initially

– must be in any database

– have a simpler structure

10. If a is the price, b is the mass, then the attribute c, denoting the cost, will be:

– basic attribute

+ virtual attribute

– complex attribute

11. A subschema of the original schema, consisting of one or more attributes for which the condition of uniqueness of values ​​in tuples of relations is declared, is called?

– global scheme of relations

+ key

– report

12. The index for a subschema consisting of several attributes is called:

+ composite

– non-unique

– difficult

13. In MS Access, it is impossible to execute a query on:

– data update

+ data creation

– adding data

14. MS Access, when closing the program:

– suggests saving the database

+ automatically saves as you enter data

– automatically saves when closing the program

15. For the database to operate efficiently, the following condition must be met:

+ data consistency

– reliability of data

– objectivity of data

16. The “Counter” field is different in that:

– integers must be entered

– only the value is stored in the field, and the data itself is stored in another field

+ it has automatic build-up

17. Which function allows you to select multiple attributes from multiple tables at once and get a new table with the result?

– form

+ request

– report

18. What are forms used for in MS Access?

+ for entering data in a convenient order

– to output data in a convenient format

– to present the final information in a convenient form

19. Which character replaces everything when querying a database?

+ symbol *

– symbol “

– symbol &

Test 20. What allows you to automate data entry into a table?

– sample

– default value

+ substitution list

21. Queries are created using:

+ query wizards

– query services

– client requests

22. Basic concepts of a hierarchical database:

– table, column, row

+ level, node, connection

– relation, attribute, tuple

23. What is the peculiarity of a factual database?

+ contains brief information about the described objects, presented in a strictly defined format

– contains information of different types

– contains information of a certain type

24. Example of a factual database:

– legislative act

– order for the institution

+ information about the institution’s personnel

25. What is an information system?

+ a set of databases and DBMS

– a set of hardware and software designed to work with information

– a set of data

26. Data is:

– presentation of information in a formalized form for working with it

– information in a certain context

+ facts that have not been processed

27. What data model can be represented by the graph shown in the figure?

– relational

– hierarchical

+ network

28. Network DB assumes:

+ the presence of both vertical and horizontal hierarchical connections

– relationships between several tables

– relationships between data in the form of a tree

29. The most accurate analogue of a relational database:

+ two-dimensional table

– vector

– unordered data set

30. The table layout is:

+ description of table columns

– description of table rows

– general view of the table