|Oracle9i OLAP Services Concepts and Administration Guide
Release 1 (9.0.1)
Part Number A88755-01
Developing OLAP Applications, 5 of 5
The types of analyses performed by your application determine the best choice of a data repository. You must examine the benefits of each storage method in light of your application and decide which one most closely matches your requirements. You can choose to store the data for your business analysis applications from these alternatives:
If you are interested in a MOLAP or HOLAP solution, then refer to Oracle9i OLAP Services Developer's Guide to the OLAP SPL for additional information.
The relational database is the preferred data repository for most query and reporting applications that require read-only access to the data. For these applications, the relational database offers scalability in supporting very large data sets efficiently and manageability with a single set of administrative tools.
Analytic workspaces should be used as a persistent data store for applications that support predictive analysis functions, such as models and forecasts, and what-if scenarios. Other design choices, such as the types of hierarchies and use of non-additive aggregation methods, may make the analytic workspace the preferred data repository.
In addition to where you store the data is the decision of what to store. Aggregate data can either be generated and stored as a data maintenance step, or aggregated whenever it is needed in response to a query. If the data is already available, then response time is quicker. However, you will need more storage space to accommodate the additional data.
In deciding what to store, you should consider the merits of several factors: how frequently the aggregate data is needed; how much time is required to generate the data; whether the response time for generating the data falls within acceptable limits; how much disk space is required to store the data; and whether you have the option of acquiring additional storage media.