Re: Announcing the "Instant Data Warehouse" Product

In article <4fanjk$h9c_at_newsbf02.news.aol.com> ndcolleen_at_aol.com (NDColleen) writes:
>From: ndcolleen_at_aol.com (NDColleen)
>Subject: Re: Announcing the "Instant Data Warehouse" Product
>Date: 7 Feb 1996 12:30:28 -0500
 

>what is ROLAP?

ROLAP is an acronym that stands for Relational OLAP. Of course, OLAP is also an acronym that stands for On-Line Analytical Processing. OLAP is a term coined by Dr. Ted Codd that basically refers to multi-dimensional data analysis. Multidimensionality refers to the many different ways in which an end user may wish to look at a given piece of data. For example, the domain of interest could be "sales." A query couldbe constructed that "looks" at sales across multiple dimensions, such as time, salesman, region, product, etc. An OLAP tool enables the user to quickly change the dimensions for a given fact domain, retrieve data based on the change, perform analysis, and change again. This discussion of OLAP is necessarily brief. For more info monitor the comp.databases.olap newsgroup.

There are two approaches to OLAP: physical OLAP (or MDB / multidimensional databases) and logical OLAP (or relation OLAP / ROLAP). MDB requires that data be aggregated and loaded in a multidimensional format. The data is then (usually) available in a read-only format. To change the data, reload the MDB (or cube as they are commonly called). ROLAP products build indexes (or some sort of virtual equivalent) on top of a relational database. Both approaches have strengths and drawbacks... MDB tools are usually quick but more difficult to maintain and have trouble scaling to large sizes. ROLAP tools are usually not as quick as as MDB but can scale as well as the RDBMS product on which they sit on top of and the data is modifiable without a complete reload.

Good luck!
Craig S. Mullins
PLATINUM technology, inc.
"The Open Enterprise Management Company" http://www.platinum.com Received on Mon Feb 12 1996 - 00:00:00 CET