2.2 Understanding Oracle APEX

Oracle APEX provides you with all the tools you need to build apps in a single, extensible platform, which runs as a part of Oracle Database.

When you install APEX, you can install either a runtime environment or a full development environment.

2.2.1 What is Oracle APEX?

Oracle APEX is a hosted declarative development environment for developing and deploying database-centric web applications. Thanks to built-in features such as user interface themes, navigational controls, form handlers, and flexible reports, APEX accelerates the application development process.

The APEX engine renders applications in real time from data stored in database tables. When you create or extend an application, APEX creates or modifies metadata stored in database tables. When the application is run, the APEX engine then reads the metadata and displays the application.

To provide stateful behavior within an application, APEX transparently manages session state in the database. Application developers can get and set session state using simple substitutions and standard SQL bind variable syntax.

2.2.2 How Oracle APEX Works

Oracle APEX installs with your Oracle database and consists of data in tables and PL/SQL code. Whether you run the APEX development environment or run an application built using APEX, the process is the same. Your browser sends a URL request that is translated into the appropriate APEX PL/SQL call. After the database processes the PL/SQL, the results are relayed back to your browser as HTML. This cycle happens each time you either request or submit a page.

APEX does not use a dedicated database connection. Instead, each request is made through a new database session, consuming minimal CPU resources. Application session state is managed in the database tables by the APEX engine.

Behind the scenes, the APEX engine renders and processes pages. The APEX engine also performs these tasks:

  • Session state management

  • Authentication services

  • Authorization services

  • Page flow control

  • Validation processing

2.2.3 About the Differences Between Runtime and Full Development Environments

When you install Oracle APEX, you can install two different environments:

  • Runtime environment. In a runtime environment users can run applications but cannot modify them. Select this option for production implementations.

  • Full development environment. In a full development environment, users can develop, modify, run, and delete APEX applications. This option provides complete access to the APEX environment described in this document.