About the OLAP Catalog

The OLAP catalog is the metadata repository provided for the OLAP option in the Oracle Database. This metadata describes the data stored in both relational tables and in analytic workspaces.

When you deploy a dimensional object using OWB, you can specify if the dimensional object metadata should be stored in the OLAP catalog.

OLAP metadata is dynamically projected through a series of views called the active catalog views (views whose names begin with ALL_OLAP2_AW).

In Oracle Database 11g, the OLAP catalog metadata is used by OLAP tools and applications to access data stored in relational star and snowflake schemas. External application such as Oracle Business Intelligence Enterprise Edition use the OLAP catalog to query relational and multidimensional data. The application does not need to be aware of whether the data is located in relational tables or in analytic workspaces, nor does it need to know the mechanism for accessing it.

Figure: Using the OLAP Catalog to Access Dimensional Objects describes how the OLAP catalog enables applications to access data stored in relational tables and analytic workspaces.

The OLAP catalog uses the metadata it stores to access data stored in relational tables or views. The OLAP catalog defines logical multidimensional objects and maps them to the physical data sources. The logical objects are dimensions and cubes. The physical data sources are columns of a relational table or view.