IDS Forum

Re: 9.4 slower than 9.3

Posted By: Jonathan Leffler
Date: Wednesday, 8 October 2003, at 7:46 p.m.

In Response To: 9.4 slower than 9.3 (Steve Willcoxon)

All the usual questions apply:

Have you reviewed the configuration in 9.4 to check that you don't have any
inappropriate settings (even if they were appropriate before)? CCFLAGS,
for example.

Have you got enough shared memory?

What do the system performance monitoring utilities say is taking the time
- is it CPU power or disk access time or something else that is causing the
hot-spot?

Have you run UPDATE STATISTICS?

Are the databases running on the same machine but different disk drives or
on the same disk drives each time?

Do you use optimizer hints/directives in the code? Have you checked
they're correct?

Are you sure you have all the indexes the same on both?

Have you run with SET EXPLAIN ON to see what the query plans look like?

If the answer to all these is yes (well, the third one doesn't take yes/no
as an answer), then maybe you should be contacting IBM/Informix Tech
Support. If you have a firm case of worse performance, we might want to
get a version of you application in house here so we can use it to prevent
similar breakdowns in future (after we've analyzed why it is causing
problems). One of the hardest things about any benchmarking is ensuring
that the setups are really, really identical, and the other is that the
results are very difficult to extrapolate to different systems.

--
Jonathan Leffler (jleffler@us.ibm.com)
STSM, Informix Database Engineering, IBM Data Management
4100 Bohannon Drive, Menlo Park, CA 94025
Tel: +1 650-926-6921 Tie-Line: 630-6921
"I don't suffer from insanity; I enjoy every minute of it!"




|---------+---------------------------->
| | "Steve Willcoxon"|
| | <stevew@shubertor|
| | g.com> |
| | Sent by: |
| | forum.subscriber@|
| | iiug.org |
| | |
| | |
| | 10/08/2003 01:31 |
| | PM |
|---------+---------------------------->
>---------------------------------------------------------------------------------------------------------------------------------------------|
| |
| To: ids@iiug.org |
| cc: |
| Subject: 9.4 slower than 9.3 [2010] |
>---------------------------------------------------------------------------------------------------------------------------------------------|





I received the following email showing 9.4 IDS to be slower than 9.3 IDS.
>From many classes and conversations I know 9.4 is faster.

Same hardware, Digital Alpha/Compaq/HP ES40 TRU64 UNIX Ver 5.1B.
Same inhouse software loaded with appropriate 9.3/9.4 libraries.
Same onconfig, same data, nothing else running.

9.30.FC1X6 and 9.40.FC2X1

Can this be a result of the conversion taking place on the fly?

Any ideas on why 9.4 appears to be almost 30% slower?

Thanx in advance,
Steve Willcoxon


Duplex and transactions in the following refers to our application and its
transactions, not Informix transactions.

Subject: 9.4 Informix Test Results

We had Imperial duplex this past Sunday and Monday with both 9.3 and 9.4
Informix. At the time of these tests, the duplex was the only thing
running
on the system. The times listed are from the beginning of the processing
of
the first transaction to the end of processing of the last transaction.
Here are the results:

9.3 Informix:
Sunday duplex - 2hr 41min
Monday duplex - 4hr 41min

9.4 Informix:
Sunday duplex - 3hr 28min
Monday duplex - 5hr 45min

So as you can see the 9.4 Informix took longer to do the same thing.

Sunday - 9.4 took 47min longer
Monday - 9.4 took 1hr 4min longer

Messages In This Thread

• 9.4 slower than 9.3
  Steve Willcoxon -- Wednesday, 8 October 2003, at 4:31 p.m.
  • Re: 9.4 slower than 9.3
    Madison Pruet -- Wednesday, 8 October 2003, at 6:22 p.m.
  • Re: 9.4 slower than 9.3
    Jonathan Leffler -- Wednesday, 8 October 2003, at 7:46 p.m.
  • RE: 9.4 slower than 9.3
    Jean-Francois BOUDRY -- Thursday, 9 October 2003, at 3:08 a.m.
  • Re: 9.4 slower than 9.3
    Steve Willcoxon -- Thursday, 9 October 2003, at 2:04 p.m.

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