Re: tough choices

From: Mark Townsend <markbtownsend_at_comcast.net>
Date: Wed, 23 Jun 2004 04:28:55 GMT
Message-ID: <bG7Cc.91523$eu.65695@attbi_s02>

datab0y_at_yahoo.com wrote:

> Actually, right now I've got several oracle & db2 systems that are
> using range partitioning.

No you don't. You have DB2 systems using union all views. Everybody has union all views.

> Of the three techniques
> Oracle's is the most sophisticated and has the most features probably,
> though MDC is working fine. Union-alls are the most similar to the
> Oracle technique though aren't nearly so polished.

There are severe limitations to the union all view approach - as a slight indicator, see a current thread in the DB2 newsgroup - http://tinyurl.com/34cv5

Some other questions to ask.
1) In a union all view scenario, how do I add/maintain/use a secondary index ?
2) In a union all view scenario, how do I get view level statistics ? 3) In a union all view scenario, how do I create a partitioned summary table ?
4) In a union all view scenario, does the query engine know which of the views below the summary table are reflected in the current refesh, and therefore eligble as a target for rewrite ? 5) In a union all view scenario, if three of the underlying tables qualify for a range scan, what degree of parallelism is obtained ?

> I assume that
> we'll see them steadily improved over the next couple of years.

Serge has indicated that IBM will add full partitioned tables to a future release, just not in the Stinger timeframes. Note that this is a huge development effort, and not undertaken likely. Oracle has spent at least 8 years adding and polishing it's partitioning capabilities, and I believe we have significantly more development resource than IBM has.

> So, actually I'm getting table partitioning for free from DB2 but have
> to pay for it from Oracle. If I want to add database partitioning to
> the table partitioning - only then do I have to pay for it from db2.

No you are not. You are getting Union All views for free. Oracle also has Union All views, for free, as well. And what indication do you have that if and when IBM add full blown partitioning, they will not charge for it ? Received on Tue Jun 22 2004 - 23:28:55 CDT