Re: Oracle Exadata Machine

I must disagree with that statement. Exadata is lot more sophisticated for such an oversimplified statement. For example, filter_predicates are applied in exadata cells nearer to the disk and can be applied in parallel. That alone can reduce the amount of communication between disk layer and host, reduces buffer_cache or PGA usage, reduces cpu usage at server lavel and improves elapsed time. More importantly, execution plan shows application of filter predicates at that exadata cell level.

Also, rows and row pieces are returned from those cells, not just the whole block. So, if the query is interested just few columns in a long table, then just those columns are returned. As you can imagine, this has the ability to reduce traffic between CPU and disk by manyfold, further reducing backplane clog.

More importantly, this is all done in software and so underlying CPUs and hardware can be upgraded without much pain points, reducing TCO. I have no clue about teradata, but I heard that upgrade of "teradata hardware" usually means replacing whole set, since teradata seems to have optimization built in to disk & disk processor level, as against exadata like software based optimization.

I realize that some complex join conditions are not pushed to exadata cells yet, but this is just first release. I am sure, in future versions, these will be pushed to exadata too.

Ouch, I sound like a marketing guy.. but, this is the fact.

Just as a disclaimer, I own no Oracle stock and I have no commercial interest with exadata either :-)

Cheers

Riyaj Shamsudeen
Principal DBA,
Ora!nternals - http://www.orainternals.com Specialists in Performance, Recovery and EBS11i Blog: http://orainternals.wordpress.com

On Wed, May 13, 2009 at 10:38 AM, Keith Moore <kmoore_at_zephyrus.com> wrote:

> We briefly looked at Netezza awhile back. The price is in the $1 million
> range. I think it would have been a good fit but for whatever reason we
> could
> not get permission to do a trial.
>
> For what it's worth, I think Neteeza has a better architecture for maximum
> raw
> performance for data warehouse queries. The customized hardware is built
> for
> that while Oracle's architecture is mostly a reconfiguration of existing
> Oracle features such as RAC along with new hardware.
>
> On the other hand, Netezza doesn't have the Oracle standard features such
> as
> PL/SQL, some of the indexing capabilities, etc.
>
> Keith
> <...snip..>
>

--
http://www.freelists.org/webpage/oracle-l