IDS Forum

Re: Update Statistics

Posted By: Fernando Nunes
Date: Wednesday, 3 March 2010, at 9:50 a.m.

In Response To: Update Statistics (Wyza, Jonathon)

UPDATE STATISTICS is a fundamental step for good database performance.
Informix query optimizer is not the most feature reach one, but it does a
great job. What I mean is that there are some ways to do queries that
Informix does not (yet) use. But the optimizer tends to choose the best
available plan. BUT, for doing that it's essential that it knows about the
data. And that is done through "good" update statistics.

The most recent article that I know of, about this subject is

http://www.ibm.com/developerworks/data/library/techarticle/dm-0803changappa/index.html

You should also take a look at the previous "bible":

http://www.ibm.com/developerworks/data/zones/informix/library/techarticle/miller/0203miller.html

but this one is obviously a bit outdated (all new stuff in Informix 11.x is
not covered).
And as usual you MUST take a look at the manual, specifically the Syntax
Guide and the Performance Guide.

You can use some tools to help you. Automatic update statistics was
introduced in Informix 11 and you can take advantage of that using Open
Admin Tool (OAT). Besides that Art Kagel has nice tools (dostats). You'll
need to compile them.
If you prefer the simplicity of shell script I can provide some (I should
put them in the IIUG software repository, but time is short - and bad
excuses are common - :( )

Regards.

On Wed, Mar 3, 2010 at 1:45 PM, Wyza, Jonathon <wyzaj@bethelcollege.edu>wrote:

> I've seen the recommendation to do update statistics on ids on this list
> over
> the last couple months in certain situations. Sadly I know little about
> administering IDS but I've muddle through so far. I was wondering if
> someone
> could do a quick tutorial about update statistics covering things like when
> to
> use it and why to use it and how often to use it.
>
> Jonathon Wyza
> CX & CBORD System Administrator
> CX Programmer/Analyst
> Administrative Computing
> Bethel College
> (574)-257-3381
> AIM: Iamwyza
> jonathon.wyza@bethelcollege.edu<mailto:jonathon.wyza@bethelcollege.edu>
> ==========================
> SLES 10 SP2 & IDS 10.0 HC9
>
> " I would love to change the world, but they won't give me the source
> code."
> -- Unknown
>
>
>
> *******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>

--
Fernando Nunes
Portugal

http://informix-technology.blogspot.com
My email works... but I don't check it frequently...

--0016e6d99efabae2850480e69b26

Messages In This Thread

• Update Statistics
  Wyza, Jonathon -- Wednesday, 3 March 2010, at 8:45 a.m.
  • Re: Update Statistics
    Fernando Nunes -- Wednesday, 3 March 2010, at 9:50 a.m.
    • RE: Update Statistics
      Wyza, Jonathon -- Wednesday, 3 March 2010, at 10:14 a.m.
      • Re: Update Statistics
        Art Kagel -- Wednesday, 3 March 2010, at 2:24 p.m.
      • RE: Update Statistics
        John Miller iii -- Wednesday, 3 March 2010, at 6:49 p.m.
  • Re: Update Statistics
    Art Kagel -- Wednesday, 3 March 2010, at 12:12 p.m.
  • Re: Update Statistics
    VIKAS HIVARKAR -- Friday, 5 March 2010, at 10:47 a.m.

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