Return-Path: Delivered-To: 2-oracle-l@orafaq.com Received: (qmail 20984 invoked from network); 7 Aug 2007 09:57:44 -0500 Received: from freelists-180.iquest.net (HELO turing.freelists.org) (206.53.239.180) by 69.64.49.119 with SMTP; 7 Aug 2007 09:57:31 -0500 Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 876A871DE4E; Tue, 7 Aug 2007 10:54:23 -0400 (EDT) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing.freelists.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 25107-04; Tue, 7 Aug 2007 10:54:23 -0400 (EDT) Received: from turing (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id C2ADE71E678; Tue, 7 Aug 2007 10:54:22 -0400 (EDT) Received: with ECARTIS (v1.0.0; list oracle-l); Tue, 07 Aug 2007 10:11:47 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 88F7671DF64 for ; Tue, 7 Aug 2007 10:11:47 -0400 (EDT) Received: from turing.freelists.org ([127.0.0.1]) by localhost (turing.freelists.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 15495-03 for ; Tue, 7 Aug 2007 10:11:47 -0400 (EDT) Received: from ironport-in2.aurora.org (smtp3.aurorahealthcare.org [198.177.95.148]) by turing.freelists.org (Avenir Technologies Mail Multiplex) with ESMTP id 4080971DC87 for ; Tue, 7 Aug 2007 10:11:45 -0400 (EDT) DomainKey-Signature: s=key768; d=aurora.org; c=nofws; q=dns; b=XZqSF4+1d6LYwgGywScMrAE/HXqJ0eCn3fPeqSZcAI13IDjeEfroTtvkPy+Fpi0Uz5Mz4WSgza+RUgItXcILm3pqvNT6/DJZPDgq39dJAvw1ouBpJ9kd5wDGPsqd4PhQ; X-IronPort-AV: E=Sophos;i="4.19,229,1183352400"; d="scan'208";a="4067891" Received: from heintsas002.aurora.org ([10.129.128.83]) by ironport-out2.aurora.org with ESMTP; 07 Aug 2007 09:14:02 -0500 To: oracle-l@freelists.org Subject: Cursor_sharing=similar.....failed MIME-Version: 1.0 Message-ID: From: daniel.hubler@aurora.org Date: Tue, 7 Aug 2007 09:12:46 -0500 X-MIMETrack: Serialize by Router on HEINTSAS002/SRV/AHC(Release 7.0.1FP1|April 17, 2006) at 08/07/2007 09:12:46, Serialize complete at 08/07/2007 09:12:46 Content-Type: multipart/alternative; boundary="=_alternative 004E308A86257330_=" X-archive-position: 366 X-ecartis-version: Ecartis v1.0.0 Sender: oracle-l-bounce@freelists.org Errors-to: oracle-l-bounce@freelists.org X-original-sender: daniel.hubler@aurora.org Precedence: normal Reply-to: daniel.hubler@aurora.org List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: oracle-l X-List-ID: oracle-l List-subscribe: List-owner: List-post: List-archive: X-list: oracle-l X-Virus-Scanned: Debian amavisd-new at localhost.localdomain --=_alternative 004E308A86257330_= Content-Type: text/plain; charset="US-ASCII" Looking for ideas/comments/suggestions.......... We changed cursor_sharing from EXACT to SIMILAR last Saturday morning at 6am. Did that via an "ALTER SESSION SET....." command. The environment is large (7TB) but not very busy on Saturday morning. We had cursor_sharing=similar in multiple test environments, for many months without issue. At 9:15am, we started to generated ora-04031 errors. By 9:30am, we could no longer sign-on. We ended up shutting down the middle-tier, and deleting all of the OS processes on the DB server, that represented connections to the instance. At that point, we were able to signon, backout the change, and startup the middle-tier again. In the alert log, we saw the ora-04031 errors, and also many (thousands) of messages saying "PMON failed to acquire latch, see PMON dump". The PMON trace file show the same entry, repeated thousands of times: "PMON unable to acquire latch 2c4cb108 library cache possible holder pid = 1000 ospid=42586708" Any ideas on what happened would be appreciated. Thanks. Dan Hubler Database Administrator Aurora Healthcare daniel.hubler@aurora.org --=_alternative 004E308A86257330_= Content-Type: text/html; charset="US-ASCII"
Looking for ideas/comments/suggestions..........

We changed cursor_sharing from EXACT to SIMILAR last Saturday morning at 6am.
Did that via an "ALTER SESSION SET....." command.
The environment is large (7TB) but not very busy on Saturday morning.
We had cursor_sharing=similar in multiple test environments, for many months without issue.

At 9:15am, we started to generated ora-04031 errors.
By 9:30am, we could no longer sign-on.
We ended up shutting down the middle-tier, and deleting all of the
OS processes on the DB server, that represented connections to the instance.
At that point, we were able to signon, backout the change, and startup the middle-tier again.

In the alert log, we saw the ora-04031 errors, and also many (thousands) of messages saying
"PMON failed to acquire latch, see PMON dump".

The PMON trace file show the same entry, repeated thousands of times:
"PMON unable to acquire latch 2c4cb108 library cache
  possible holder pid = 1000 ospid=42586708"


Any ideas on what happened would be appreciated.
Thanks.




Dan Hubler
Database Administrator
Aurora Healthcare
daniel.hubler@aurora.org --=_alternative 004E308A86257330_=-- -- http://www.freelists.org/webpage/oracle-l