DDIC cache

The Data Dictionary Cache (DDIC) is a cache that holds information about SAP function modules, structure definitions, Business Objects, ALE mappings, and IDocs. SAP® ERP retrieves this information from an SAP system when it runs RFC, BAPI, or IDoc lookups. To improve performance, SAP® ERP caches information that it receives about function modules and structure definitions.

SAP® ERP receives information about function modules and structure functions when:

An RFC, BAPI, or IDoc lookup is requested.
SAP® ERP runs a service that starts an RFC or BAPI on an SAP system.
An SAP system runs an RFC that starts a service.
An IDoc gets processed by SAP® ERP.

SAP® ERP keeps separate cached function modules, structure definitions, Business Objects, ALEmappings, and IDocs for each SAP system. When SAP® ERP requires specific data, it checks its DDIC cache for the specific SAP system to determine whether the information it requires is in the cache. If the required information is in the DDIC cache, SAP® ERP uses the cached information rather than retrieving it from the SAP system.

The DDIC cache is always active and no configuration tasks that are required to activate it. When you are developing services, at times when the information in the DDIC cache becomes outdated; for example, if you change an RFC signature on an SAP system. In these situations, you can use the DDIC cache screens to view the information in the cache and remove specific function modules or structure definitions from the cache as necessary.

System ID: Uniquely identifies an SAP system within an SAP domain. RFC connections that use the same system IDs share the cache.
Note: If you have configured and enabled an RFC listener, you see a Local entry in the System ID list. The cached elements of this System ID cannot be deleted or modified.
Functions: Number of cached function modules for an SAP system. You can view the function module names by clicking the number in the Functions field. You can clear the individual function module from the cache by clicking the Delete icon.
Structures: Number of cached structure definitions for an SAP system. You can view the structure module names by clicking the number in the Structures field. You can clear the individual structure module from the cache by clicking the Delete icon.
Business objects: Number of cached business objects for an SAP system. You can view the business object names by clicking the number in the Business objects field. You can clear the individual business object from the cache by clicking the Delete icon.
ALE mappings: Number of cached BAPIs for an SAP system (for which ALE information of an SAP system is checked and extracted). You can view the ALE-mapping module names by clicking the number in the ALE mappings field. You can clear the individual ALE-mapping module from the cache by clicking the Delete icon.
IDocs: Number of cached function IDocs for an SAP system. You can view the IDoc names, IDoc type extension, and release information by clicking the number in the IDocs field. You can clear the individual IDoc from the cache by clicking the Delete icon.