Database and file concepts：练习题

In a relational database, which of the following is defined as a field or a set of fields in one table that refers to the primary key in another table to establish a link between the data?

A database developer is creating a data dictionary for a new system. Which of the following would NOT typically be included as a component of a data dictionary entry for a specific field?

A table is in Second Normal Form (2NF) but contains a transitive dependency (where a non-key attribute is dependent on another non-key attribute). What must be done to bring this table into Third Normal Form (3NF)?

A database designer is using a primary key in one table as a field in another table to create a relationship.
What is the specific name of this field in the second table?

A database developer is selecting a method to access records in a very large file where records are stored in a specific order based on a key field. The system needs to support both batch processing of all records and occasional fast access to individual records.

Which access method is most appropriate?

State the primary difference between a flat file and a relational database.

Describe how a Management Information System (MIS) uses database data to assist a manager in making strategic decisions.

Evaluate the use of referential integrity in a relational database, specifically explaining the consequences to the child table if a record is deleted from the parent table without it.

A national retail company manages a customer database that has become increasingly difficult to maintain due to data redundancy.

(a) Describe the characteristics of a database table that is in First Normal Form (1NF).
(b) Explain the advantages of normalizing a database to Third Normal Form (3NF) for an organization.

A developer is creating a data dictionary for a new library management system that tracks books, authors, and loans. The 'Loans' table currently contains the following fields: Loan_ID, Book_ISBN, Member_ID, Date_Out, and Returned_Status.

(a) Identify four different components that should be included in a data dictionary for each field listed above.
(b) Explain why it is vital to create a data dictionary during the design phase of a database before any actual data is entered.