Re: Striping and CI Locks

From: Fraser McCallum <fmcc_at_NOSPAModbaguru.com>
Date: Mon, 4 Feb 2002 19:43:52 -0000
Message-ID: <tvB78.15229$bP3.122840@NewsReader>

A CI lock is a "Cross-instance Call Invocation" lock. Despite what the name may suggest it is not specific to Oracle Parallel Server. It use used for specific actions by background processes including shutting down, checkpoint, log switch, and identifying or re-identifying datafiles. I don't think that your CI level should have changed due to moving to a Stripe set!

With regards to DB_WRITERS I do remember having a problem with using a value greater than 0 with Async IO and also that you should not have more than two per disk spindle.... not sure how you would relate this back to moving from Single Disks to Stripe set though.

Kind Regards

Fraser McCallum
MVP Oracle Administration
www.brainbench.com

"Christian Lang" <clang_at_mediaprint.at> wrote in message news:6cf185c9.0202040626.7e252796_at_posting.google.com...
> Hi,
> at the last weekend I moved our 130G Production DB (7.3.4.5 on Solaris
2.6)
> from Single Disks to a Stripe set.
> --
> Today I detect that many sessions have to wait for enqeue
> --
> SELECT ksqsttyp "Lock",
> ksqstget "Gets",
> ksqstwat "Waits"
> FROM X$KSQST where KSQSTWAT>0;
> --
> CF 71 2
> CI 6572 1109
> SQ 5277 59
> ST 1067 179
> TM 162497 24
> TS 1295 8
> TX 67239 263
>
> My question:
> Could the CI Locks be associated with the StripSet ?
> Could the init.ora Param. DB_WRITERS=4 be associated with the StripSet ?
>
> any help will be appreciated
> Chris
>
Received on Mon Feb 04 2002 - 13:43:52 CST