RE: Reading sequences is much slower in AIX 6.1 than Linux
Date: Tue, 11 Oct 2011 11:11:59 -0400
Message-ID: <021c01cc8828$20b0f880$6212e980$_at_rsiz.com>
Hermitize your sequences. I've previously published the instructions and scripts to do this seamlessly restoring your existing sequence definitions and parameters. Be careful, especially if you have auditing turned on, because you do not want any sequence generation going on if you include the step to rebuild sys owned sequences. I have tested this only through 11.1.x, but the fundamentals of this storage have not changed since V6. In OPS it was laughable to attempt more than 2 nodes without this fix.
If you rebuild seq$ one row per block you will ameliorate tendency to cross ping blocks for sequences. The root cause is likely some reduction in a sys sequence cache size or inclusion of ordering. (But I'm neither Oracle nor dev.)
If you write your own, remember to temporarily reduce your sequence cache size on each sequence if you need to avoid burning a bunch of sequence numbers on the restart.
Your mileage may vary. If you screw this up it is not my fault.
Regards,
mwf
-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org]
On Behalf Of Bobak, Mark
Sent: Monday, October 10, 2011 5:52 PM
To: exriscer_at_gmail.com; Chitale, Hemant Krishnarao
Cc: oracle-l_at_freelists.org
Subject: RE: Reading sequences is much slower in AIX 6.1 than Linux
That's a concern....
Do you have a bug number?
-Mark
-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org]
On Behalf Of LS Cheng
Sent: Monday, October 10, 2011 5:34 PM
To: Chitale, Hemant Krishnarao
Cc: oracle-l_at_freelists.org
Subject: Re: Reading sequences is much slower in AIX 6.1 than Linux
oracle support opened a bug but not AIX related, it is a RAC bug, gettings sequences are much much slower in 11.2.0.2 RAC currently under development investigation!
On Thu, Sep 29, 2011 at 8:34 AM, Chitale, Hemant Krishnarao < Hemant.Chitale_at_sc.com> wrote:
> ** **
>
> Can you check to see if the cached values are being "lost" frequently
(i.e.
> the sequence is not pinned and is getting aged-out) ?****
>
> ** **
>
>
> Hemant K Chitale
>
> ****
>
> ** **
>
> *From:* LS Cheng [mailto:exriscer_at_gmail.com]
> *Sent:* Thursday, September 29, 2011 2:31 PM
> *To:* Chitale, Hemant Krishnarao
> *Cc:* oracle-l_at_freelists.org
> *Subject:* Re: Reading sequences is much slower in AIX 6.1 than
> Linux****
>
> ** **
>
> ops forgot to mention that, cache size is 500000 and noorder
>
> Thanks****
>
> On Thu, Sep 29, 2011 at 7:30 AM, Chitale, Hemant Krishnarao <
> Hemant.Chitale_at_sc.com> wrote:****
>
> What are the CACHE_SIZE and ORDER_FLAG (sometimes used in RAC) for the
> SEQUENCE_S1 sequence in the two environments ?
>
>
> Hemant K Chitale****
>
>
> -----Original Message-----
> From: oracle-l-bounce_at_freelists.org
> [mailto:oracle-l-bounce_at_freelists.org]
> On Behalf Of LS Cheng
> Sent: Thursday, September 29, 2011 1:17 PM
> To: Oracle Mailinglist
> Subject: Reading sequences is much slower in AIX 6.1 than Linux
>
> Hi all
> We have some batch processes which need to meet some SLA, the
> execution time should exceed certaint threshold of time. The processes
> are mainly insert.... select sequence, ... from table.****
>
> ...deleted......
>
>
>
> ****
>
> ** **
>
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