Search Results enqueue_event

Overview

APPS.WF_QUEUE is the Oracle Workflow queuing infrastructure package in Oracle E-Business Suite 12.1.1 and 12.2.2. It provides the PL/SQL API layer through which the Workflow Engine moves event and item-activity messages between producers and subscribers, using the Oracle Streams Advanced Queuing (AQ) facilities of the database. The package abstracts the physical queue tables so that callers can enqueue an event, dequeue an inbound or outbound message, process deferred events, and purge obsolete queue content without directly manipulating AQ structures or WF_QUEUES configuration rows. It is classified in ETRM as an OTHER API within the APPS schema, and it is a load-bearing component: it is referenced by nine other packages, including WF_ENGINE, WF_ENGINE_BULK, WF_ENGINE_UTIL, WF_ITEM_ACTIVITY_STATUS, WF_XML, WF_OAM_METRICS, FND_OAM_EM, WF_REPOPULATE_AQ, and WFJ_QUEUE, which is the Workflow Java queue consumer. Because of this dependency footprint, WF_QUEUE underpins both the Business Event System and the internal runtime signalling between workflow processes.

Key Procedures and Functions

The documented API exposes thirty-nine procedures and functions. The core enqueue/dequeue surface includes ENQUEUEINBOUND and DEQUEUEOUTBOUND, which push and pull messages on the inbound and outbound AQ queues; ENQUEUE_EVENT and DEQUEUE_EVENT, which operate on the Workflow event queue; DEQUEUEEVENTDETAIL, which retrieves the detail payload of a queued event; and DEQUEUEEXCEPTION, which retrieves messages that failed during processing so they can be inspected or reprocessed.

Queue processing and housekeeping are handled by PROCESSINBOUNDQUEUE, PROCESSDEFERREDQUEUE and PROCESSDEFERREDEVENT, DEFERREDQUEUE, and ENABLEBACKGROUNDQUEUES, which activate the background agents that drain the queues. INBOUNDQUEUE and OUTBOUNDQUEUE return the configured queue identities used by the runtime. Purge operations are performed by PURGEEVENT and PURGEITEMTYPE, which remove processed event and item-type queue rows. Subscriber management is provided by ADDSUBSCRIBER. Utility functions include GETMESSAGEHANDLE, which returns a handle to a dequeued message, GET_PARAM_LIST, which builds a parameter list, SET_QUEUE_NAMES, which assigns the physical queue names, and CLEARMSGSTACK, which empties the message stack maintained during queue processing. Functions such as PROCESSINBOUNDQUEUE return status or count information used by schedulers.

Tables Accessed

WF_QUEUE reads and writes the workflow definition and runtime tables through APPS synonyms. WF_QUEUES, ALL_QUEUES, and ALL_QUEUE_TABLES supply queue configuration and the underlying AQ table definitions, while DBMS_AQ provides the enqueue and dequeue primitives. Event and subscription routing relies on WF_EVENT_T, WF_AGENTS, and WF_AGENT_T. Activity-level queue content is resolved against WF_ACTIVITIES, WF_ACTIVITY_ATTRIBUTES, WF_ACTIVITY_ATTR_VALUES, and WF_PROCESS_ACTIVITIES, with runtime state drawn from WF_ITEMS, WF_ITEM_ACTIVITY_STATUSES, and WF_ITEM_ACTIVITY_STATUSES_H. WF_SYSTEMS identifies the participating workflow systems. WF_PAYLOAD_T is referenced as a type dependency used in message payloads.

Usage Notes

WF_QUEUE is not typically called from Oracle Forms; it is invoked by the Workflow Engine and by concurrent programs such as the Workflow Agent Listeners, the Workflow Background Process, and the deferred and inbound queue processing programs. Business Event System subscribers and the WFJ_QUEUE Java consumer also call into it. Custom code should generally use the higher-level WF_EVENT and WF_ENGINE APIs rather than WF_QUEUE directly, since direct enqueue or dequeue calls bypass validation performed by those layers. Administrators interact with it indirectly when purging workflow queues, re-enabling background queues after maintenance, or troubleshooting stuck events, making awareness of its purge and queue-processing procedures essential during patching and cloning activities.