Application Developers
Once the database has been implemented, the application programs that provide the
required functionality for the end-users must be implemented. This is the responsibility of
the application developers. Typically, the application developers work from a specification
produced by systems analysts. Each program contains statements that request the
DBMS to perform some operation on the database. This includes retrieving data, inserting,
updating, and deleting data. The programs may be written in a third-generation programming
language or a fourth-generation language, as discussed in the previous section.
End-Users
The end-users are the ‘clients’ for the database, which has been designed and implemented,
and is being maintained to serve their information needs. End-users can be classified
according to the way they use the system:
n Naïve users are typically unaware of the DBMS. They access the database through
specially written application programs that attempt to make the operations as simple as
possible. They invoke database operations by entering simple commands or choosing
options from a menu. This means that they do not need to know anything about the
database or the DBMS. For example, the checkout assistant at the local supermarket
uses a bar code reader to find out the price of the item. However, there is an application
program present that reads the bar code, looks up the price of the item in the database,
reduces the database field containing the number of such items in stock, and displays
the price on the till.
n Sophisticated users. At the other end of the spectrum, the sophisticated end-user is
familiar with the structure of the database and the facilities offered by the DBMS.
Sophisticated end-users may use a high-level query language such as SQL to perform
the required operations. Some sophisticated end-users may even write application programs
for their own use.
Once the database has been implemented, the application programs that provide the
required functionality for the end-users must be implemented. This is the responsibility of
the application developers. Typically, the application developers work from a specification
produced by systems analysts. Each program contains statements that request the
DBMS to perform some operation on the database. This includes retrieving data, inserting,
updating, and deleting data. The programs may be written in a third-generation programming
language or a fourth-generation language, as discussed in the previous section.
End-Users
The end-users are the ‘clients’ for the database, which has been designed and implemented,
and is being maintained to serve their information needs. End-users can be classified
according to the way they use the system:
n Naïve users are typically unaware of the DBMS. They access the database through
specially written application programs that attempt to make the operations as simple as
possible. They invoke database operations by entering simple commands or choosing
options from a menu. This means that they do not need to know anything about the
database or the DBMS. For example, the checkout assistant at the local supermarket
uses a bar code reader to find out the price of the item. However, there is an application
program present that reads the bar code, looks up the price of the item in the database,
reduces the database field containing the number of such items in stock, and displays
the price on the till.
n Sophisticated users. At the other end of the spectrum, the sophisticated end-user is
familiar with the structure of the database and the facilities offered by the DBMS.
Sophisticated end-users may use a high-level query language such as SQL to perform
the required operations. Some sophisticated end-users may even write application programs
for their own use.
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