Search Results cache_changed

Overview

WF_ENTITY_MGR is a PL/SQL package body in the APPS schema that provides the attribute-caching infrastructure for the Oracle Workflow (WF) engine. Its core business function is to manage the wf_attribute_cache table, which stores entity-attribute name/value pairs keyed by entity type and entity key value. This cache allows Workflow components, notification mailers, and related runtime processes to resolve entity attributes efficiently without repeatedly querying the underlying base tables. The package is classified as OTHER in the ETRM metadata for 12.1.1 and 12.2.2, reflecting its role as a low-level internal service rather than a public business API.

The package is best known in the context of the "get_attribute_value" search because GET_ATTRIBUTE_VALUE is one of its eight documented procedures. It is the runtime accessor used to retrieve a cached attribute for a given entity. The header reflects version 120.3 dated 2006/04/04, indicating the object has been stable across the 11i and R12 releases.

Key Procedures and Functions

The ETRM metadata documents eight procedures/functions. Their purposes are:

• GET_ATTRIBUTE_VALUE — Retrieves the cached value of a named attribute for a specified entity type and entity key. This is the primary read interface into the attribute cache and the object most commonly referenced by customizations.
• PUT_ATTRIBUTE_VALUE — Writes or updates an attribute value in the cache. Internally this delegates to the private put routine, which locks the cache row, calls InitCache when necessary, and commits the change.
• PROCESS_CHANGES — Processes pending cache changes, typically resolving attributes marked with a change number. This supports the incremental refresh model used by the Workflow engine.
• FLUSH_CACHE — Clears or invalidates cache entries for an entity, forcing subsequent reads to re-query the source data.
• PURGE_CACHE_ATTRIBUTES — Physically removes stale attribute rows from the cache table, supporting housekeeping and cache-size control.
• GET_ENTITY_TYPE — Returns the entity type associated with a given entity, used to resolve the correct caching namespace.
• GEN_XML_PAYLOAD — Generates an XML representation of entity attributes, used where Workflow requires structured payloads.
• ISCHANGED — Determines whether a cached attribute has changed since a prior state, supporting change-detection logic.

The private routines InitCache and put are not part of the documented API but are visible in the source excerpt. InitCache creates a CACHE_CHANGED attribute set to PENDING using an autonomous transaction, and put constructively writes cache rows while skipping the sentinel value *UNKNOWN*.

Tables Accessed

The package reads and writes WF_ATTRIBUTE_CACHE, the central cache table containing entity_type, entity_key_value, attribute_name, attribute_value, last_update_date, and change_number. The put routine updates this table and relies on its unique index (the source handles DUP_VAL_ON_INDEX as a race condition). The metadata also lists WF_PARAMETER_LIST_T, a Workflow parameter-list type used to pass attribute collections, and the DBMS_LOB and XMLDOM packages, which support payload generation in GEN_XML_PAYLOAD.

Usage Notes

WF_ENTITY_MGR is not typically invoked directly from Oracle Forms. It is called by the Workflow engine and by other PL/SQL packages—the metadata records that it is referenced by nine other packages. Developers who need to read or write entity attributes from custom code should call GET_ATTRIBUTE_VALUE and PUT_ATTRIBUTE_VALUE rather than manipulating WF_ATTRIBUTE_CACHE directly, ensuring proper cache locking and commit behavior. Because InitCache uses an autonomous transaction, cache initialization is visible to all sessions immediately. Diagnostic logging is controlled through WF_LOG_PKG at the procedure runtime level.