What are the different types of Strategies?

In Designer we can specify two types of strategies:

1) Built-in strategies and

2) External strategies

Built-in Strategies: Designer provides a number of default strategies which we can use. These are strategies for extracting joins, detecting cardinalities, and creating default classes and objects. Options for indicating default strategies are located in the Database tab of the Options dialog box.

External Strategies: We can also create our own strategies. Such strategies are referred to as external strategies. With an external strategy, we can specify the exact way that objects and joins are to be extracted from the database structure. The strategy we use, for example, can be a script generated from a CASE Access tool. An external strategy is specific to one RDBMS.

How do you specify external strategies?

With an external strategy, you can specify the exact way that objects and joins are to be extracted from the database structure. All external strategies are contained within the same text file. The name of this text file is indicated in the .prm file specific to your RDBMS. In the .prm file, the strategy file is declared as follows:

STG=[StrategyFileName] where StrategyFileName is the name of the strategy file.

An external strategy, whether for objects or for joins, is made up of the following sections:

a name and description (These are visible in the Strategies tab of the Universe Parameters dialog box.)
a type parameter: object or join
an SQL parameter or file parameter
an optional parameter that points to a connection other than the universe connection.

An external strategy can be based on SQL or a file.