Updating SAS OLAP Cubes

Input Data Tables for Cube Updates

When you add data to a cube, you must select a table that contains the new data for the cube. This might be new data for existing members or new members with new data. The table must be defined in the metadata repository and it must contain all the columns for the measures. Depending whether you are incrementally updating the cube or rebuilding the cube, you must manage the input data accordingly. If you are updating the cube incrementally, then your table does not need to contain all the cumulative data. However, if you are rebuilding the cube, then your input tables must contain all the data from the original build and all the incremental updates.

If you are rebuilding a cube, it is very important that the data used as input to the rebuilt cube contain all the incremental updates that have been made since the original cube was created. This can be done one of two ways:

The input base or fact table definition in the SAS metadata should be a view that combines the original input table plus all subsequent update tables into a single logical table. This is the recommended approach.
The input base or fact table itself is physically updated to add data from all update tables.

It is not possible for PROC OLAP or SAS OLAP Cube Studio to verify the correctness of the input data. This is the responsibility of the administrator or cube builder. Depending on what data source the cube is loaded from, some requirements apply:

Input Table Considerations
Data Source	Requirement
Detail table	All the level columns must be in the new data table.
Star schema	The foreign key columns must be in the new data table. However, the level columns must be in the dimension table along with the unique key columns. For star schema cubes, you do not have to select a source table. If a source table is not selected, then only the dimension tables will be processed and only if the UPDATE_DIMENSION option is set to MEMBERS or MEMBERS_AND_PROPERTIES for the dimension. No new data is added to the cube. In this case, the ADD_DATA option should not be added to the PROC OLAP statement. You can, however, still specify new dimension tables and specify a value for the UPDATE_DIMENSION option. This is only valid for dimensions in a star schema that originate from a dimension table. Dimensions in a star schema that come from the fact table can only be updated if a source table is selected and ADD_DATA is specified on the PROC OLAP statement.
Fully summarized table	The cube cannot be updated.

When you add data to a cube, the cube and its corresponding tables must be kept in synch. When you add new members to the cube using the Incremental Update process, the original tables are re-read by PROC OLAP unless a different table is provided.

Note: If the original dimension table for a star schema is updated with the new members, you do not need to select a table for a dimension. [cautionend]

Top of Page