Materialized Views and OLAP Metadata

You should create materialized views after you have defined the OLAP metadata for your star schema. You may have used Enterprise Manager to create CWM metadata, or you may have developed scripts to create CWM2 metadata, or you may have some combination of CWM and CWM2 metadata.

However, the structure of the metadata in the OLAP Catalog does not affect the structure of the materialized views that enable query rewrite at runtime. The choices you make in establishing materialized views will be based primarily on the structure of the data in the star schema and on the query requirements of OLAP clients.

See Also: Chapter 5, "Creating OLAP Catalog Metadata" for information about defining OLAP metadata.

CWM Metadata

CWM metadata for dimension tables and fact tables is visible within the property pages for dimensions and cubes in the OLAP folder of Enterprise Manager. OLAP Summary Advisor generates concatenated rollup style MVs for cubes that are visible within Enterprise Manager.

If you wish to create grouping set style materialized views for CWM metadata, then you must develop your own scripts using the DBMS_ODM package. OLAP Summary Advisor does not support this type of materialized view.

See Also: Chapter 31, "Creating Fact Materialized Views With OLAP Summary Advisor".

CWM2 Metadata

CWM2 metadata is not visible within the OLAP folder of Enterprise Manager. Thus, you cannot use OLAP Summary Advisor with CWM2 metadata.

To create materialized views for CWM2 metadata, use the DMBS_ODM package. DBMS_ODM contains procedures for creating dimension MVs and grouping set style MVs.

To create materialized views in grouping set form for a star schema that is mapped to CWM2 metadata, use the DBMS_ODM package.

See Also: Chapter 30, "Creating Fact Materialized Views With DBMS_ODM".