7.31 performance problem
A user upgrading Informix from 7.24 to 7.31 on HP-UX 10.20 (20GB database, 4 CPUs, 1GB RAM) reported general performance degradation after the move. Respondents pressed for migration details (in-place upgrade vs. dbexport/dbimport) and whether UPDATE STATISTICS had been run; one suggested checking onstat -P for a high Btree buffer percentage, pointing to a known buffer-prioritization bug, and asked for various onstat outputs. The main advice for an in-place upgrade was to drop all indexes, run UPDATE STATISTICS LOW DROP DISTRIBUTIONS, rebuild the indexes, then re-run UPDATE STATISTICS per the performance guide. The poster never reported back, so no confirmed resolution is recorded.
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Hi! We changed Informix version from 7.24--->7.31 and after that we have regonised some prformance problems. Our database is about 20Gb. Is there some general things that we haven't regoniced or has anybody had same kind of problems? Thank's in forward KT
In the year of Our Lord Mon, 18 Dec 2000 14:13:04 +0200, kt <h78816@loisto.uwasa.fi> broke a vow of silence to utter: >Hi! > >We changed Informix version from 7.24--->7.31 and after that we have >regonised some prformance problems. > >Our database is about 20Gb. > >Is there some general things that we haven't regoniced or has anybody had >same kind of problems? There's lots of known issues. How did you migrate?
Update statistics?
AJ
kt wrote:
>
> Hi!
>
> We changed Informix version from 7.24--->7.31 and after that we have
> regonised some prformance problems.
>
> Our database is about 20Gb.
>
> Is there some general things that we haven't regoniced or has anybody had
> same kind of problems?
>
> Thank's in forward
>
> KT
Hi! I'm sorry for the delay in my answer. But in anyway, we didn't do anything special with the upgrade. As before with the older version. We installed the 7.31 in another disk and made the database with same script as before. Whats new on the system is a new pair of 18Gb disks. The system is HP-UX B.10.20 U 9000/800 149470502 unlimited-user license, Mem 1Gb, 4 Cpus. KT > >We changed Informix version from 7.24--->7.31 and after that we have > >regonised some prformance problems. > > > >Our database is about 20Gb. > > > >Is there some general things that we haven't regoniced or has anybody had > >same kind of problems? > > There's lots of known issues. How did you migrate? > >
In the year of Our Lord Mon, 18 Dec 2000 21:29:03 +0200, kt
<h78816@loisto.uwasa.fi> broke a vow of silence to utter:
>I'm sorry for the delay in my answer.
>
>But in anyway, we didn't do anything special with the upgrade. As before
>with the older version.
So you did an in-place upgrade? No dbexport/dbimport?
>We installed the 7.31 in another disk and made the database with same
>script as before.
Does this mean you unloaded/reloaded or what? Did you do UPDATE STATISTICS as
per the performance guide?
>Whats new on the system is a new pair of 18Gb disks.
>
>The system is HP-UX B.10.20 U 9000/800 149470502 unlimited-user
>license, Mem 1Gb, 4 Cpus.
>
>> >We changed Informix version from 7.24--->7.31 and after that we have
>> >regonised some prformance problems.
>> >
>> >Our database is about 20Gb.
>> >
>> >Is there some general things that we haven't regoniced or has anybody had
>> >same kind of problems?
>>
>> There's lots of known issues. How did you migrate?
In article <Pine.GSO.4.30.0012181408590.22423-100000@loisto.uwasa.fi>,
kt <h78816@loisto.uwasa.fi> wrote:
> Hi!
>
> We changed Informix version from 7.24--->7.31 and after that we have
> regonised some prformance problems.
>
> Our database is about 20Gb.
>
> Is there some general things that we haven't regoniced or has anybody
had
> same kind of problems?
>
> Thank's in forward
>
> KT
>
>
I recall there being a buffer prioritization bug which could be causes
performance degredation.
onstat -P | tailIf the Btree percentage is really high you might be hitting that bug.
Give us a little more information about the degredation.
O/S
exact version (such as 7.31UC2)
onstat -m
onstat -c
onstat -g iov
onstat -D
onstat -R
onstat -F
onstat -g glo
onstat -P | tail
all these would be helpful as well.
Hope to help,
Will
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> So you did an in-place upgrade? No dbexport/dbimport?
Yes of course.
> >We installed the 7.31 in another disk and made the database with same
> >script as before.
> Does this mean you unloaded/reloaded or what?
No we have a one script that we are using for to crete the complete
database with indexes and everything.
>Did you do UPDATE STATISTICS as
> per the performance guide?
Yes.
Thanks
KT
In the year of Our Lord Mon, 18 Dec 2000 22:24:02 +0200, kt
<h78816@loisto.uwasa.fi> broke a vow of silence to utter:
>> So you did an in-place upgrade? No dbexport/dbimport?
>
>Yes of course.
I feel like I'm in a Monty Python movie. Did you do an in-place upgrade?
If you *did* do an in-place upgrade:
1. DROP all indexes;
2. UPDATE STATISTICS LOW DROP DISTRIBUTIONS;
3. recreate all indexes;
4. UPDATE STATISTICS as per the performance guide.