15.2 Organization of the Warehouse Process Package

   The Warehouse Process package depends on the following packages: • org.omg::CWM::ObjectModel::Core • org.omg::CWM::ObjectModel::Behavioral • org.omg::CWM::Analysis::Transformation

   A WarehouseProcess object represents the processing of a transformation. It is instantiated as one of its subtypes WarehouseActivity or WarehouseStep, depending on whether it represents the processing of a TransformationActivity or a Transformation Step.

   A WarehouseProcess may be associated with one or more WarehouseEvents, each identifying events that cause the processing to be initiated. It may also be associated with one or more internal events that will be triggered when processing terminates.

   A ProcessPackage may be used to group together related WarehouseActivities.

   WarehouseProcess WarehouseEvent

   TransformationActivity TransformationStep (from Transformation) (from Transformation)

   Figure 15-1 Warehouse Process package overview.

   WarehouseEvents are divided into three categories: scheduled, external, and internal.

   Scheduled events can either be defined as a point in time (each Wednesday at 2 pm) or be defined by intervals (every five minutes). A point in time event can be defined as a custom calendar that contains a set of calendar dates. This allows a series of dates to be reused across several WarehouseProcesses.

   External events are triggered by something happening outside the data warehouse, for example by a batch process that is not described as a WarehouseProcess.

   Internal events are triggered by the termination of a WarehouseProcess. They can be either retry events or cascade events. Retry events normally trigger a rerun of the same WarehouseProcess, whereas cascade events normally trigger a different WarehouseProcess. An internal event may define a condition that determines whether or not the event is triggered. This condition can use details of the execution of the triggering WarehouseProcess recorded in the relevant ActivityExecution and StepExecution objects.

   WarehouseProcess WarehouseEvent

   triggeringWP

   InternalEvent ScheduleEvent ExternalEvent

   RetryEvent CascadeEvent PointInTimeEvent

   RecurringPointInTimeEvent CustomCalendarEvent

   CalendarDate /ownedElement /namespace CustomCalendar

   Figure 15-2 Warehouse Events and Custom Calendars

   Package ModelElement (from Core) (from Core)

   Event(from Behavioral)

   Figure 15-3 Warehouse Process package inheritance structure

    Figure 15-4 shows how the scheduled (every Wednesday at 2 pm) unload process cascades with the load process.

   Figure 15-4 Instance diagram of cascade event.