1. () can reduce the phenomenon of repeated storage of the same data
A. Record B. Field C. File D. Database
Answer: D.
A database is a collection of organized, shareable, and large amounts of data stored in a computer for a long time, with less redundancy and higher data independence.
2. The term in the information world, the corresponding database term is ()
A. File B. Database C. Field D. Record
Answer: D
Information world is an entity, which is stored as a record in a table in the database.
3. The database administrator is a person who specializes in developing databases. ()
Answer: False.
Database developers include database administrators, database designers, application programmers, and more.
4. The database type is divided according to ().
A. Data description function B. Record form C. Data model D. Data access method
Answer: The C
relational database system adopts the relational model as the data organization method.
5. The main function of the database management system is ( )
A. Modify the database B. Define the database C. Apply the database D. Protect the database
Answer: B
6. The definition of the index is stored in the object referred to by which of the following ()
A, view B, schema C, data dictionary D, file
Answer: The C
data dictionary is a set of system tables inside the DBMS system, which records all the definition information in the DB, including the definition of relational schema, view definition, index definition, integrity constraint definition, and various user permissions to operate the database definition etc.
7. If the candidate key of the relation schema R is a single attribute, then R must be _____NF.
Answer: 2
Single attribute, there is no partial functional dependence of non-primary attributes on the code.
8. Selection is an operation that selects several attributes from a relationship to form a new relationship ()
Answer: False
Selection is the operation of finding tuples from a relation that satisfy a given condition. Projection is the operation of selecting several attributes from a relationship to form a new relationship.
9. In a relational database, in order to simplify the user's query operation without increasing the storage space of the data, the method often used is to create ()
A, index B, cursor C, view D, trigger
Answer: The C
view can simplify the user's operation. At the same time, the view does not store the corresponding data, so it does not occupy storage space.
10. In relational algebra, from the Cartesian product of two relations, the operation of selecting tuples that satisfy certain conditions between their attributes is called ()
A. projection B. selection C. natural connection D. connection
Answer: D
Selection is the operation of finding tuples from a relation that satisfy a given condition. Projection is the operation of selecting several attributes from a relationship to form a new relationship. Connection: From the Cartesian product of two relations, select tuples that satisfy certain conditions between their attributes, where the natural connection requires the components to be compared in the two relations to be the same attribute group, and remove duplicate attributes in the result .