Active Catalog Metadata Cache

The Active Catalog views present information stored within analytic workspaces. This information is also stored for fast access in a separate set of cache tables in the Database.

The Active Catalog views are named with the ALL_OLAP2_AW prefix. The views of the cache tables, which have the same column structure, are named with the MRV_OLAP2_AW prefix.

Applications that require fast access to the Active Catalog should query the cached metadata in the MRV_OLAP2_AW views. You should continue to use CWM2_OLAP_AC_REFRESH to ensure that all the MRV_OLAP2_AW views are synchronized with the ALL_OLAP2_AW views.

The metadata cache is not automatically refreshed when changes are made to the Active Catalog. To refresh the cache, use the CWM2_OLAP_METADATA_REFRESH package, as described in Chapter 19.

The OLAP API queries the Active Catalog cache to obtain the logical model stored in an analytic workspace. You must refresh the cache for OLAP applications that use analytic workspaces.

In the current version of the Active Catalog, the performance of some of the views has been enhanced. These views no longer use the caching mechanism, and the MRV_OLAP2_AW views are simply copies of the ALL_OLAP2_AW views. However, if you are using an earlier version of standard form, caching is used for all the Active Catalog views.