Example of database system engineer's examination questions

1. The description of the data view used by a single user is called ().

A. External mode

B. Conceptual model

C. internal model

D. storage mode

2. The sub-mode ddl is used to describe ()

A. the overall logical structure of the database

B. Local logical structure of database

C. Physical storage structure of the database

D. Conceptual structure of the database

3. In the database system, the relationship between the database management system and the operating system is ().

A. Call each other

B.dbms calls the operating system

C. The operating system calls dbms.

D. and send questions in the afternoon.

In the afternoon, I mainly test the specific application of the database, master the SQL statement, relational operation and schema decomposition of the database, and master the design and optimization of the database. Test1(* *15)

Read the instructions below, answer questions 1 and 2, and fill in the answers in the corresponding columns on the answer sheet.

explain

Suppose a large commercial enterprise consists of a commodity distribution center and a supermarket chain, in which the commodity distribution center includes departments such as purchasing, finance and distribution. In order to achieve efficient management, the information management system of commodity distribution center is designed, and its main functions are described as follows: the system receives the supply request of chain supermarkets and records it in the supply request record file. After receiving the supply request, query the commodity inventory information from the commodity inventory record file. If the inventory meets the supply requirements, send delivery notice to delivery processing; Otherwise, issue a shortage notice to the purchasing department. After receiving the delivery notice, the delivery processor queries the delivery request record file, updates the commodity inventory record file, sends the delivery list to the delivery department, and records the delivery information into the commodity delivery record file at the same time of delivery. After receiving the out-of-stock notice, the purchasing department negotiates with the supplier, carries out the purchase processing of the goods, puts the qualified goods into storage, records the documents from the purchase order to the purchase order, sends the delivery notice to the delivery processing, and informs the finance department to pay the payment to the supplier. The system is developed by structured method, and the data flow diagram to be modified is obtained (as shown in figure 1- 1). Question 1(8)

Using the words in the description, the names of external entities E 1 to E4 and data storage D 1 to D4 in the diagram1are given.

Question 2(7 points)

The graph 1- 1 has four wrong data streams. Please point out their starting and ending points. If the above four wrong data streams are deleted, three more data streams will be added to ensure the correctness of the data stream diagram. Please give the starting point and ending point of the added data stream. (Please use the symbols or names in the data flow diagram 1- 1 for the starting point and the ending point. )