Database Reference
In-Depth Information
7
DBMS FUNCTIONS
CHAPTER
LEARNING OBJECTIVES
Introduce the functions, or services, provided by a DBMS
Describe how a DBMS handles updating and retrieving data
Examine the catalog feature of a DBMS
Illustrate the concurrent update problem and describe how a DBMS handles this problem
Explain the data recovery process in a database environment
Describe the security services provided by a DBMS
Examine the data integrity features provided by a DBMS
Discuss the extent to which a DBMS achieves data independence
Define and describe data replication
Present the utility services provided by a DBMS
INTRODUCTION
In this chapter you learn about nine critical functions performed by a DBMS. Some of the functions have been introduced in
previous chapters; however, they are emphasized again here because they are key processing components of a DBMS.
The nine functions of a DBMS are:
Update and retrieve data.
A DBMS must provide users with the ability to update and retrieve data in a database.
Provide catalog services.
A DBMS must store data about the data in a database and make this data accessible
to users.
Support concurrent update.
A DBMS must ensure that the database is updated correctly when multiple users
update the database at the same time.
Recover data.
A DBMS must provide methods to recover a database in the event that the database is damaged in
any way.
Provide security services.
A DBMS must provide ways to ensure that only authorized users can access the
database.
Provide data integrity features.
A DBMS must follow rules so that it updates data accurately and consistently.
Support data independence.
A DBMS must provide facilities to support the independence of programs from the
structure of a database.
Support data replication.
A DBMS must manage multiple copies of the same data at multiple locations.
Provide utility services.
A DBMS must provide services that assist in the general maintenance of a database.
