Programming strategies

ODABA supports different ways of programming. Typically, fast implementation methods as by means of OSI script language may cause performance problems. Well performing implementation strategies are more time consuming. Usually, scripting is useful for prototype development and for most GUI application rules. Using one of the supported programming languages will improve application performance.

In general, one has to choose between three different strategies:

• Scripting - Implementing methods by means of OSI script language
• Generic access - Implementing application rules in a high level programming language (C#, JAVA) or using generic C++ implementations
• Typed access - Implementing methods in C++ based on class definitions created from persistent data types

In principle, different strategies may be mixed, i.e. one may implement some methods using one of the supported programming language and others by means of OSI. The only restriction is, that one programming language should be chosen, which may be mixed with OSI. Hence, using typed access, requires C++/OSI applications, while generic access may use JAVA or C#.

ODABA applications comprise mainly three areas:

• Stand alone programs - typically used for running batch jobs or performing maintenance tasks
• Business rules - are implemented in database context classes in order to handle events for properties and types (comparable to triggers and stored procedures in relational databases)
• GUI Application rules - are implemented as application context classes within the GUI frame work.

Usually, a strategy has to be chosen for each of the defined areas, i.e. different strategies may be used e.g. for business and application rules.

The following sections describe implementation rules for different strategies used for implementation in all three areas.