Informix' s performans 
Author Message
 Informix' s performans

On my UNIX AIX 4.3+IDS 7.23 escala 204M
(2 powerpc 187Mhz, 5 disk raid 5, 1GB ram, 2MB cache)
a query returns in 38 seconds.

On my Win 2000 Server+SQL server 7
(Celeron 900Mhz, simple disk ide 20GB, 128MB ram, 128KB cache)
the same query, on the same tables (3 table join), with the same indexs,
with the same records, returns in 4 seconds.

I dont' think that difference is true.

Do someone know if difference could dipend from:
-hardware
-operative sistem
-db
-other....
??????????????????????

If I canghe my engine to a SQL server DB, where can I find
problems????

Thanks a lot.
Miche.



Mon, 07 Jun 2004 15:54:37 GMT
 Informix' s performans

NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5

But also:

Quote:

>On my UNIX AIX 4.3+IDS 7.23 escala 204M
>(2 powerpc 187Mhz, 5 disk raid 5, 1GB ram, 2MB cache)
>a query returns in 38 seconds.

>On my Win 2000 Server+SQL server 7
>(Celeron 900Mhz, simple disk ide 20GB, 128MB ram, 128KB cache)
>the same query, on the same tables (3 table join), with the same indexs,
>with the same records, returns in 4 seconds.

>I dont' think that difference is true.

>Do someone know if difference could dipend from:
>-hardware

Definitely a possibility. Also, the informix version is very old. An
upgrade might help!
Quote:
>-operative sistem
>-db
>-other....
>??????????????????????

>If I canghe my engine to a SQL server DB, where can I find
>problems????

>Thanks a lot.
>Miche.



Mon, 07 Jun 2004 18:54:46 GMT
 Informix' s performans



Quote:
> NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
[cut]
> NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5

What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????
What does it mean???????????????????????????????????????????????

Ciaoooooooooo, Miche.



Mon, 07 Jun 2004 19:04:00 GMT
 Informix' s performans
Don't use RAID 5.
Quote:



>> NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5
>[cut]
>> NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5 NO RAID 5

>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????
>What does it mean???????????????????????????????????????????????

>Ciaoooooooooo, Miche.



Mon, 07 Jun 2004 19:04:51 GMT
 Informix' s performans

Quote:
> Don't use RAID 5.

You are a big writer :-)))))))))))
Why do you say it?
It impreves performace and allows you to have a disk
crash without problems (1 year ago I canghe 1 of them
without turn off the machine).

If you don't have a lot time to write, can you say me where
to read the reasons of yours thoughts?

Thanks a lot.
Miche.



Mon, 07 Jun 2004 19:17:27 GMT
 Informix' s performans

Quote:

>> Don't use RAID 5.

>You are a big writer :-)))))))))))
>Why do you say it?
>It impreves performace and allows you to have a disk
>crash without problems (1 year ago I canghe 1 of them
>without turn off the machine).

To both of the above, I say bollocks. I've seen performance fall
through the floor when moving from JBoD to RAID 5 and I've also had a
RAID 5 pack let go with both hands, never to be rebooted. (Not the
same site, though)
Quote:
>If you don't have a lot time to write, can you say me where
>to read the reasons of yours thoughts?


>> > >I have seen several recommendations to avoid RAID 5.  Can someone tell
>> > >me exactly what the problems with RAID 5 are?

>>Most of those disparaging postings are from me.  There are two problems
>>with RAID5.  The first is performance which is the one most people notice
>>and if you can live with write throughput which is 50% of the equivalent
>>RAID0 stripe set then that is fine.  The performance hit is caused because
>>RAID5 ONLY reads the one drive containing the requested sector leaving the
>>other drives free to return other sectors from different stripe blocks.
>>This is the reason that RAID5 is preferred to RAID3 or RAID4 for
>>filesystems, this feature improved small random read performance.  However,
>>since the parity and the balance of the stripe block were not read, if you
>>rewrite the block (which databases do far more frequently than filesytems)
>>the other drives must all be read and a new parity calculated and then
>>both the modified block and the parity block must be written back to disk.
>>This READ-WRITE-READ-WRITE for each modified block is the reason RAID5 is
>>so poor in terms of write throughput.  Large RAID controller caches and
>>on controller firmware level RAID implementations alleviate the problem
>>somewhat but not completely and write performance still hovers at around
>>half what a pure stripe (RADI0) would get.

>>The second problem, despite what others have said IS a FUNDAMENTAL problem
>>with the design of RAID5 which various implementors have tried to correct
>>with varying levels of success.  The problem is that if a drive fails
>>slowly over time, known as partial media failure, where periodically a
>>sector or two goes bad, this is NOT detected by RAID5's parity and so
>>is propagated to the parity when that sector is rewritten which means that
>>if another drive fails catastrophically its data will be rebuilt utilizing
>>damaged parity resulting in two sectors with garbage.  Now this may not
>>even be noticed for a long time as modern SCSI drives automatically remap
>>bad sectors to a set of sectors set asside for the purpose but the
>>corrected error is NOT reported to the OS or the administrators.  Over
>>time if the drive is going it will run out of remap sectors and will have
>>to begin returning data reconstructed from the drive's own ECC codes.
>>Eventually the damage will exceed the ECC's ability to rebuild a single
>>bit error per byte and will return garbage.

>>RAID3 and RAID4 are superior in both areas.  In both all drives are read
>>for any block which improves sequential read performance (Informix Read
>>Ahead depends on sequential read performance) over RAID5 and parity can
>>be (and in most implementations IS) checked at read time so that partial
>>media failure problems can be detected.  Write performance is
>>approximately the same as RAID0 for large writes or smaller stripe block
>>sizes.  One problem with early implementations of RAID3/4 was slow parity
>>checking since it has to be calculated for every read and every write.
>>Modern controller based RAID systems use the on-board processor on the
>>SCSI controller to perform the parity checks without impacting system
>>performance by tying up the a system CPU to check and produce parity.
>>These RAID levels require the exact same number of drives as RAID5.

>>RAID10 provides the best protection and performance with read performance
>>exceeding any other RAID level (since both drives of a mirrored pair can
>>be reading different sectors on parallel) and write performance is closest
>>to pure striping.  Indeed in a hardware/firmware implemented RAID10 array
>>with on-board cache apparent write throughput can exceed RAID0 for brief
>>periods due to the two drives of each pair being written to independently
>>though the gain is not sustainable over time.

>>A third problem with ALL RAID3/4/5 from which RAID10 does not suffer is
>>multiple drive failure.  (Ever get a batch or 200 bad drives?  We have!)
>>If one drive in a RAID3/4/5 array fails catastrophically you are at risk
>>for complete data loss if ANY of the remaining 4 (or more) drives should
>>fail before the original failed drive can be replaced and rebuilt.  With
>>RAID10, since it is made up as a stripe set of N mirrored pairs, when a
>>drive fails you are only at risk for complete data loss if that one drives
>>particular mirror partner should fail.  Make each mirrored pair from
>>drives selected from different manufacturer's lots and the probability of
>>this happening become vanishingly small.

>>Fourth problem.  During drive rebuild RAID3/4/5 (and RAID01 mirrored
>>stripe sets) performance of the array during the rebuild can degrade by
>>as much as 80%!  Some RAID systems let you tune the relative priority of
>>rebuild versus production to reduce the performance hit to as low as about
>>40% degradation but this will increase the recovery time increasing the
>>number of production requests that are degraded and increasing the risk
>>of the previous problem with a second drive failure.  RAID10, since only
>>one drive is involved in mirror recovery, the array's performance (for a
>>4 drive array) is degraded only a maximum of 80% for reads and writes
>>against the failed pair and only slightly (due to controller traffic) for
>>accesses to the other drives, on average, since the one pair comprises
>>only 20% of accesses, performance is affected no more than 16% during
>>recovery and the risk of catastrophic data loss is reduced.

>>Well this concludes my quarterly RAID5 rant for anyone who has had trouble
>>finding my earlier ones.

>>Art S. Kagel



Mon, 07 Jun 2004 20:14:40 GMT
 Informix' s performans

On IDS7.23 - when last did you run update statistics on these 3 tables ?

Just a thought.

Quote:
-----Original Message-----

Sent: 20 December 2001 09:55

Subject: Informix' s performans

On my UNIX AIX 4.3+IDS 7.23 escala 204M
(2 powerpc 187Mhz, 5 disk raid 5, 1GB ram, 2MB cache)
a query returns in 38 seconds.

On my Win 2000 Server+SQL server 7
(Celeron 900Mhz, simple disk ide 20GB, 128MB ram, 128KB cache) the same
query, on the same tables (3 table join), with the same indexs, with the
same records, returns in 4 seconds.

I dont' think that difference is true.

Do someone know if difference could dipend from:
-hardware
-operative sistem
-db
-other....
??????????????????????

If I canghe my engine to a SQL server DB, where can I find problems????

Thanks a lot.
Miche.



Mon, 07 Jun 2004 19:43:32 GMT
 Informix' s performans

Quote:
----- Original Message -----


Sent: Thursday, December 20, 2001 2:17 PM
Subject: R: R: Informix' s performans

> > Don't use RAID 5.

> You are a big writer :-)))))))))))
> Why do you say it?
> It impreves performace and allows you to have a disk
> crash without problems (1 year ago I canghe 1 of them
> without turn off the machine).

Ask Art, or better take a look through c.d.i archive at www.google.com
Quote:

> If you don't have a lot time to write, can you say me where
> to read the reasons of yours thoughts?

> Thanks a lot.
> Miche.



Mon, 07 Jun 2004 21:20:35 GMT
 Informix' s performans

Quote:
 ----- Original Message -----


Sent: Thursday, December 20, 2001 2:17 PM
Subject: R: R: Informix' s performans

> > Don't use RAID 5.

> You are a big writer :-)))))))))))

Yes you right! I know, Clowny is really famous writer!
Quote:
> Why do you say it?
> It impreves performace and allows you to have a disk
> crash without problems (1 year ago I canghe 1 of them
> without turn off the machine).

> If you don't have a lot time to write, can you say me where
> to read the reasons of yours thoughts?

> Thanks a lot.
> Miche.



Mon, 07 Jun 2004 21:27:32 GMT
 Informix' s performans

Would you care to share the query, the schema, the explain plan, and the
contents of the systables entries for those tables?  It's hard to formulate
answers without knowing the question.  SQL-server tends to 'take care' of
things for you that Informix does not.

Update stats is certainly the first place you should look, but ask us the
whole question, not something like:

    "What's the difference between a duck"

cheers
j.

Quote:
----- Original Message -----


Sent: Thursday, December 20, 2001 2:54 AM
Subject: Informix' s performans

> On my UNIX AIX 4.3+IDS 7.23 escala 204M
> (2 powerpc 187Mhz, 5 disk raid 5, 1GB ram, 2MB cache)
> a query returns in 38 seconds.

> On my Win 2000 Server+SQL server 7
> (Celeron 900Mhz, simple disk ide 20GB, 128MB ram, 128KB cache)
> the same query, on the same tables (3 table join), with the same indexs,
> with the same records, returns in 4 seconds.

> I dont' think that difference is true.

> Do someone know if difference could dipend from:
> -hardware
> -operative sistem
> -db
> -other....
> ??????????????????????

> If I canghe my engine to a SQL server DB, where can I find
> problems????

> Thanks a lot.
> Miche.



Mon, 07 Jun 2004 23:21:37 GMT
 Informix' s performans

Quote:
>-----Original Message-----

>  "What's the difference between a duck"

A duck's quack does not have an echo ?


Mon, 07 Jun 2004 23:46:07 GMT
 
 [ 11 post ] 

 Relevant Pages 

1. I want to Performans tunning

2. Couldn't create a linked server to INFORMIX using Informix OleDb provider

3. Eleven FAQ's About comp.databases.informix and informix-list@iiug.org

4. Eleven FAQ's About comp.databases.informix and informix-list@iiug.org

5. Ten FAQ's About comp.databases.informix and informix-list@iiug.org

6. Ten FAQ's About comp.databases.informix and informix-list@iiug.org

7. Eleven FAQ's About comp.databases.informix and informix-list@iiug.org

8. Ten FAQ's About comp.databases.informix and informix-list@iiug.org


 
Powered by phpBB® Forum Software