Re: Joel's Performance Issues WAS : Opteron vs Xeon - Mailing list pgsql-performance

From Josh Berkus
Subject Re: Joel's Performance Issues WAS : Opteron vs Xeon
Date
Msg-id 200504201322.37425.josh@agliodbs.com
Whole thread Raw
In response to Re: Joel's Performance Issues WAS : Opteron vs Xeon  ("Joel Fradkin" <jfradkin@wazagua.com>)
Responses Re: Joel's Performance Issues WAS : Opteron vs Xeon
List pgsql-performance
Joel,

> I have MSSQL running on a 2 proc dell which until my load has increased
> (over aprx 2 years) it was just fine. I totally agree that there are better
> solutions based on this lists comments, but I have all Dell hardware now
> and resist trying different vendors just to suit Postgres. I was under the
> impression there were still issues with 64bit postgres and Linux (or at
> least were when I purchased). I believed I could make my next aquistion a
> opteron based hardware.

Yeah, sorry, the Dell stuff is a sore point with me.   You can't imagine the
number of conversations I have that go like this:
"We're having a severe performance problem with PostgreSQL"
"What hardware/OS are you using?"
"Dell *650 with RHAS 3.0 ...."

BTW, which Update version is your RHAS?   If you're on Update3, you can grab
more performance right there by upgrading to Update4.

> Again I am not at all trying to critasize any one, so please except my
> apology if I some how came across with that attitude. I am very
> disappointed at this point. My views may not be that great (although I am
> not saying that either), but they run ok on MSSQL and appear to run ok on
> MYSQL.

Yeah.  I think you'll find a few things that are vice-versa.   For that
matter, I can point to a number of queries we run better than Oracle, and a
number we don't.

Your particular query problem seems to stem from some bad estimates.   Can you
post an EXPLAIN ANALYZE based on all the advice people have given you so far?

> I wish I did understand what I am doing wrong because I do not wish to
> revisit engineering our application for MYSQL.

I can imagine.

> I would of spent more $ with Command, but he does need my data base to help
> me and I am not able to do that.

Yes.  For that matter, it'll take longer to troubleshoot on this list because
of your security concerns.

> I agree testing the whole app is the only way to see and unfortunately it
> is a time consuming bit. I do not have to spend 4k on MYSQL, that is if I
> want to have their premium support. I can spend $250.00 a server for the
> commercial license if I find the whole app does run well. I just loaded the
> data last night and only had time to convert one view this morning. I am
> sure it is something I do not understand and not a problem with postgres. I
> also am willing to take time to get more knowledgeable, but my time is
> running out and I feel honestly stupid.

You're not.  You have a real query problem and it will require further
troubleshooting to solve.  Some of us make a pretty handsome living solving
these kinds of problems, it take a lot of expert knowledge.

> It was never my intention to make you feel like I was flaming anyone
> involved. On the contrary, I feel many have taken time to look at my
> questions and given excellent advice. I know I check the archives so
> hopefully that time will help others after me.

Well, I overreacted too.   Sorry!

> I may find that revisiting the datasets is a way to make PG work, or as you
> mentioned maybe I can get some one with more knowledge to step in locally.
> I did ask Tom if he knew of anyone, maybe some one else on the list is
> aware of a professional in the Tampa FL area.

Well, Robert Treat is in Florida but I'm pretty sure he's busy full-time.

> Realistically I don't think a 30k$ Dell is a something that needs to be
> junked. I am pretty sure if I got MSSQL running on it, it would outperform
> my two proc box. I can agree it may not have been the optimal platform. My
> decision is not based solely on the performance on the 4 proc box.

Oh, certainly it's too late to buy a Sunfire or eServer instead.   You just
could have gotten far more bang for the buck with some expert advice, that's
all.   But don't bother with Dell support any further, they don't really have
the knowledge to help you.

So ... new EXPLAIN ANALYZE ?

--
--Josh

Josh Berkus
Aglio Database Solutions
San Francisco

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