1. Among the three stages of data management development, the stage where there is no special software to manage data is ().
A. File system
B, database
C, manual management
D, manual management and document management
reference answer C
2. It is () that describes the global logical structure and characteristics of all data in the database.
A, user mode
B, internal mode
C, mode
D, external mode
reference answer C
3. The ER diagram provides a way to represent entity types, attributes, and connections. Among them, the entity type is ().
A, ellipse
B, undirected side
C, rhombus
D, rectangle
reference answer D
4. The relationship between database (DB), database system (DBS) and database management system (DBMS) is ().
A, DBS includes DB and DBMS
B, DBS is DB, that is, DBMS
C, DBMS includes DB and DBS
D, DB includes DBS and DBMS
reference answer A
5. The three elements of the data model are ().
A, field, tuple, code
B, domain, relationship, component
C, data structure, data operation, integrity constraint
D, entity, attribute, contact
reference answer C
6. To ensure the data independence of the database, what needs to be modified is ().
A. Mode and inner mode
B, mode and outer mode
C, second-level mapping between three-level mode
D, three-level mode
reference answer C
7. The following is not the responsibility of the database administrator ().
A. Define the security requirements and integrity constraints of the data.
B. Determine the storage structure and access strategy
of the database. C. Database system design.
D. Monitor the use and operation of the database.
Reference answer C.
8. There is only one relationship ().
A, main attribute
B, main code
C, foreign code
D, candidate code
reference answer B
9. The operation used to split the table in the horizontal direction is ().
A, connect
B, projection
C, cross
D, choose
reference answer D
10. The constraint rule that the "primary attribute" in the relationship does not allow null values is ().
A. Referential integrity rules
B, user-defined integrity rules
C, entity integrity rules
D, data integrity rules
refer to answer C
11. It is () that describes how the data is organized within the database.
A, user mode
B, internal mode
C, mode
D, external mode
reference answer B
12. The five basic relational algebra operations are ().
A, ∪, -, ×, σ, π
B, ∪, ∩, ×, σ, π
C, ∪, -, σ, π
D, ∪, ∩, σ, π
reference answer A
13. The description of the part of the local logical structure and characteristics seen by the user or application is ().
A, external mode
B, mode
C, internal mode
D, physical mode
reference answer A
14. Among the following four items, the one that does not belong to the characteristics of the database system is ().
A. High data redundancy
B, high data sharing and high data independence
C, data structured
D, data is managed and controlled by DBMS in a unified way.
Reference answer A
15. To ensure the physical independence of the database data and the program, what needs to be modified is ().
A. Mode and outer mode image
B, mode and inner mode image
C, two-layer image between three-level mode
D, three- layer image between the
reference answer B
16. To ensure the logical independence of the database data and the program, what needs to be modified is ().
A. Mode and external mode image
B, mode and internal mode image
C, two-layer image between three-level mode
D, three- layer image between the
reference answer A
17. There can be one or more candidate codes in relational mode, and the main code has ().
A, multiple
B, 0
C, 1
D, 1 or more
reference answers C
18. In the relationship, the attribute set that can uniquely identify the tuple is called the relationship mode ().
A, candidate code
B, main code
C, foreign code
D, foreign key
reference answer A