Re: Announcing the "Instant Data Warehouse" Product

Space: I have seen MDB applications take up far less space than relatively the same data as stored in their production RDB's. I don't think there is yet a rule of thumb that can be applied to the space expansions between MDB and ROLAP DB optimized space. There is also lots of good and poor design, with huge space implications on each end. The delivery objectives of the "warehouse" have a lot to do with it. The generalizations posted in this thread may not apply case by case.

In terms of speed and throughput there is a certain amount of "pay me now or pay me later" to this argument, with space, "batch time", and online speed as some of the variable. The time spent in load/aggregation and the space for summaries pays back in faster online response time. It's not fair to look at the space savings of a "calc on the fly" without also mentioning the slower response time.

You also have to trade off the load/aggregation time if they exceeds the production window available as the utility to the end user diminishes and sometimes evaporates completely. Again depending on the end objective and required response time different designs accomplish different goals.

I still do have a problem with an "engineered solution" that can bring that much hardware to its knees, even a whole planet's worth of processors. The software or design should prevent that kind of problem, unless of course you want to redefine a Himalaya as a "personal computer".

There are a lot of variables involved in the pros and cons of ROLAP vrs. MDB, and in leaving data atomic, or pre aggregating to some levels in both worlds. Will Gee did a good job stating the specific objectives for Woolworths. Other retailers have different goals and require different approaches. This is not a one solution takes all world, much as the Vendor community would like to think of that as a possible outcome.

Besides, not a lot of people out there can cost justify a space shuttle as a general purpose tool, but I do know a great bridge for sale........ Received on Sat Feb 17 1996 - 00:00:00 CET