The following APIs can be called by an application program or workflow function in the runtime phase to purge obsolete runtime and design data. These APIs are defined in the PL/SQL package called WF_PURGE.
WF_PURGE can be used to purge obsolete runtime data for completed work items, obsolete runtime data not associated with work items, design information for obsolete activity versions that are no longer in use, expired ad hoc users and roles, and cached user definition data in the WF_ATTRIBUTE_CACHE and WF_ENTITY_CHANGES tables. You may want to periodically purge this obsolete data from your system to increase performance.
A PL/SQL variable called "persistence_type"in the WF_PURGE package defines how most of the WF_PURGE APIs behave, with the exception of TotalPerm(). When the variable is set to TEMP, the WF_Purge APIs only purge data associated with Temporary item types, whose persistence, in days, has expired. The persistence_type variable is set to TEMP by default and should not be changed. If you need to purge runtime data for item types with Permanent persistence, you should use the procedure TotalPerm(). See: Persistence Type.
Important: You cannot run any WF_PURGE API for a future end date. By entering a future end date, you may inadvertently violate the persistence period for Temporary item types. The WF_PURGE APIs will display an error message if you enter a future end date.
The three most commonly used procedures are:
WF_PURGE.ITEMS - purge all runtime data associated with completed items, their processes, and notifications sent by them.
WF_PURGE.ACTIVITIES - purge obsolete design versions of activities that are no longer in use by any item.
WF_PURGE.TOTAL - purge both item data and activity design data.
The other auxiliary routines purge only certain tables or classes of data, and can be used in circumstances where a full purge is not desired.
The complete list of purge APIs is as follows:
Note: The AdHocDirectory() API from earlier versions of Oracle Workflow is replaced by the Directory() API. The current version of Oracle Workflow still recognizes the AdHocDirectory() API for backward compatibility, but moving forward, you should only use the new Directory() API where appropriate.
You can also use the "Purge Obsolete Workflow Runtime Data" concurrent program to purge obsolete item type runtime status information. See: Purge Obsolete Workflow Runtime Data.