Understanding the Program Life Cycle

Development: In the development phase, you create C source code procedures and integrate them into applications. Database access is provided through embedded SQL statements which are translated by a preprocessor into C procedures. After preprocessing the source, you compile, test, and debug, until the application is satisfactory. Then you install the application on a production system.

Production: In the production phase, the application runs more or less continuously. The goals in this phase are to provide a high degree of concurrent access to data consistent with data security. The programmer can often enhance the performance of an application during production runs by using specific techniques as the code is developed. During production, the database administrator (DBA) can also help improve performance by monitoring the system's use of resources and by allocating additional disk space or shared memory as needed.

Maintenance: In the maintenance phase, you modify the application in response to the changing needs of its users. This may mean updating the code, changing the security structure, or adding code to accomodate changes in the DBEnvironment. By careful coding to anticipate future developments in your databases, you can avoid the need to make extensive changes to production software.