IDS Forum

Re: How to check informix DB bottlenecks

Posted By: Art Kagel
Date: Tuesday, 2 March 2010, at 9:53 p.m.

In Response To: Re: How to check informix DB bottlenecks (JACK PAPA)

The change in the frequency of running UPDATE STATISTICS could have an
impact on performance of certain queries, so that is an issue.

The comms delays are also a serious issue for this user. You can try
turning on OPTOFC for that session and see if it helps. That option reduces
the number of communications packets send between the session and the server
both ways and can help when communications are slow. Have your network folk
take a look at the router or switch that's between this particular user and
the server to see if there are errors being seen there and perhaps swap it
out for a new one.

FYI, a full UPDATE STATISTICS HIGH on the full database isn't necessary and
takes much longer than running through the recommended suite of commands.
You can use my dostats utility to automatically implement this protocol for
you. Dostats is contained in the package utils2_ak which you can download
from the IIUG Software Repository. Note that the current dostats source
file, dostats_ng.ec for Next Generation, does not support IDS 9.40 so you'll
have to modify the makefile to compile the older source file
dostats.ecwhich is also included in the package.

Art

Art S. Kagel
Advanced DataTools (www.advancedatatools.com)
IIUG Board of Directors (art@iiug.org)

See you at the 2010 IIUG Informix Conference
April 25-28, 2010
Overland Park (Kansas City), KS
www.iiug.org/conf

Disclaimer: Please keep in mind that my own opinions are my own opinions and
do not reflect on my employer, Advanced DataTools, the IIUG, nor any other
organization with which I am associated either explicitly, implicitly, or by
inference. Neither do those opinions reflect those of other individuals
affiliated with any entity with which I am affiliated nor those of the
entities themselves.

On Tue, Mar 2, 2010 at 9:26 PM, JACK PAPA <informix2009@gmail.com> wrote:

> First let me thank all of you guys for the nice inputs, really appreciated.
> The real problem actually is the user is complaining that they are
> experiencing too much slowness when performing a select, even just it is a
> simple select.
>
> The thing i noticed on the table they are complaining is this
>
> "extent size 256000 next size 32000 lock mode row";, the table they are
> complaining is locked on a per row basis. The thing is, on the original
> box,
> all are working normally, until it was migrated to a new box. database
> version, OS version are the same, the application is the same. The only
> changes are the network configuration and the hardware. Does the network
> plays
> a big part? on the user who is testing the application, when he tried to
> issue
> "ping hostname", the latency is quite high "160 average". from my pc, it's
> just "45".
>
> To Andrea, onstat -g ses pid|grep user|sort -n -k 9,shows these are the
> biggest pids..
>
> 93324aa0 Y--P--- 103041 user1 0 93884608 0 1 616345 158815
> 9ccf36e8 Y--P--- 102960 user1 0 9fbb8a18 0 1 743498 168588
> 9029f178 ---PR-- 110770 user1 0 0 0 2 3054975 1683
> 902a7da0 Y--P--- 2788 user1 0 94821068 0 1 8010009 1613611
>
> ----
> for pid 2788 which consumes the biggest mem.
>
> => onstat -g ses 2788
>
> IBM Informix Dynamic Server Version 9.40.UC6 -- On-Line (Prim) -- Up 2 days
> 07:57:56 -- 2251504 Kbytes
>
> session #RSAM total used dynamic
> id user tty pid hostname threads memory memory explain
> 2788 user1 0 385090 Server1 1 1236992 1166864 off
>
> tid name rstcb flags curstk status
> 3457 sqlexec 902a7da0 Y--P--- 2264 cond wait(netnorm)
>
> Memory pools count 1
> name class addr totalsize freesize #allocfrag #freefrag
> 2788 V 9110e020 1236992 70128 2557 92
>
> name free used name free used
> overhead 0 1648 mtmisc 0 864
> resident 0 1248 scb 0 1400
> opentable 0 101104 filetable 0 8864
> ru 0 464 log 0 4208
> temprec 0 16200 keys 0 36504
> ralloc 0 868368 gentcb 0 1208
> ostcb 0 2736 sort 0 56
> sqscb 0 72144 sql 0 40
> rdahead 0 448 hashfiletab 0 280
> osenv 0 1792 buft_buffer 0 8352
> sqtcb 0 11728 fragman 0 17792
> udr 0 8152
>
> sqscb info
> scb sqscb optofc pdqpriority sqlstats optcompind directives
> 9127e2a8 91186018 0 1 0 0 1
> ............................................
> .....
>
> NOTE:
>
> The "update statistics high" is executed on a weekly basis. Before, it was
> 3x
> a week but it was stopped due to conflict with other running jobs.
>
>
>
> *******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>

--001517477f86daed650480dc9492

Messages In This Thread

• How to check informix DB bottlenecks
  JACK PAPA -- Tuesday, 2 March 2010, at 2:22 a.m.
  • AW: How to check informix DB bottlenecks
    Andreas.KUTSCHE@spar.at -- Tuesday, 2 March 2010, at 4:04 a.m.
    • Re: AW: How to check informix DB bottlenecks
      JACK PAPA -- Tuesday, 2 March 2010, at 4:37 a.m.
      • AW: AW: How to check informix DB bottlenecks
        Andreas.KUTSCHE@spar.at -- Tuesday, 2 March 2010, at 5:01 a.m.
      • Re: AW: How to check informix DB bottlenecks
        Art Kagel -- Tuesday, 2 March 2010, at 7:02 a.m.
      • RE: AW: How to check informix DB bottlenecks
        Jack Parker -- Tuesday, 2 March 2010, at 9:00 a.m.
  • Re: How to check informix DB bottlenecks
    Art Kagel -- Tuesday, 2 March 2010, at 6:42 a.m.
    • Re: How to check informix DB bottlenecks
      JACK PAPA -- Tuesday, 2 March 2010, at 9:26 p.m.
      • Re: How to check informix DB bottlenecks
        Art Kagel -- Tuesday, 2 March 2010, at 9:53 p.m.
      • RE: How to check informix DB bottlenecks
        Jack Parker -- Tuesday, 2 March 2010, at 9:54 p.m.
        • AW: How to check informix DB bottlenecks
          Andreas.KUTSCHE@spar.at -- Wednesday, 3 March 2010, at 4:01 a.m.
      • AW: How to check informix DB bottlenecks
        Andreas.KUTSCHE@spar.at -- Wednesday, 3 March 2010, at 3:57 a.m.
      • RE: How to check informix DB bottlenecks
        Wyza, Jonathon -- Wednesday, 3 March 2010, at 8:41 a.m.

IDS Forum is maintained by Administrator with WebBBS 5.12.