Using the OLAP DML

When should I use the OLAP DML?

There are three situations where you might use the OLAP DML:

• When you need to calculate data that cannot be calculated as part of your data warehouse extraction, transformation, and load (ETL) process or using the Java OLAP API.

• When your application needs to perform and persist various calculations, but you do not want to immediately commit this calculation to the data warehouse.

• You want to use a data file that was created with Oracle Express Server with OLAP Services.

The common calculations for which you will need OLAP DML

The most common types of calculations that the OLAP DMS is used for includes:

• Forecasts

• Models (a group of calculations in which the results of one calculation is required by another calculation -- refer to Chapter 7 for more information)

• Allocations

• Some types of non-additive aggregations (consolidations), such as hierarchical weighted averages

In addition, the OLAP DML can be used when you want to perform calculations that are not easily accomplished in the ETL process or using the OLAP API.

Because analytic workspaces are not stored in the relational database, it is possible for you to commit data to the analytic workspace without committing it to the data warehouse. This is very useful for work in process. For example, you might have a forecasting application where you want to allow users to save personal forecasts and reuse them during a later session, but you do not want that user to commit the forecast to the data warehouse.