PSP Concepts

A PSP procedure is the sequence of steps involved in transforming an input row set into an output row set. Examples of steps include a call to a business service, an instance of a transform, a conditional branch, a subprocedure call, or a terminator (an end step). A PSP procedure is any workflow that uses methods from the Row Set Transformation Toolkit business service.

A controller workflow is the invocation mechanism for the PSP engine. A PSP procedure is always called by a controller workflow. A controller workflow retrieves contextual information, invokes a generic PSP procedure, and then processes the results. It insulates the underlying PSP logic (such as a pricing procedure) from the calling context (such as repricing a quote or pricing an XML order passed in through a Web service). For more details on controller workflows, see Controller Workflow.

A row set is a property set that conforms to the structure defined in About Row Sets. It is used to represent the set of data upon which the PSP engine operates (such as data for quote line items).

The Row Set Transformation Toolkit is a business service that exposes a set of methods called transforms. Transform methods are called by steps within a PSP procedure. A transform accepts one or more input row sets, performs a series of operations (such as database queries), and then returns an updated version of the row sets as output. Special step input arguments called actions define the processing performed by a particular step. An action can perform a wide variety of updates to the input row set (such as setting the Net Price field value). Most transforms have a defined set of transform conditions that occur while the transform is executing (for example, the Simple Look-Up transform queries the database and then raises one or more of the following conditions: On First Match, On Match, On Last Match, On No Match). The condition raised depends on the result of the SQL query. Actions are attached to these conditions.