RE: Suggestions Needed: Latch free - library cache

[Bobak, Mark]

Title: Message

It usually involves rewriting the application.  Ideally, (in the perfect world), each required SQL is hard parsed once (by whomever is the first to execute it since the last bounce), that person should never need to parse it again, just rebind and re-execute as needed.  Users connecting later will parse once (this will be a soft parse cause it's in the cache from the first guy parsing it), and then rebind and re-execute as needed.  Often, with application designs the way they are, and particularly with pre-packaged apps, this is difficult.   -Mark         Mark J. Bobak Oracle DBA ProQuest Company Ann Arbor, MI "Imagination was given to man to compensate him for what he is not, and a sense of humor was provided to console him for what he is."  --Unknown -----Original Message----- From: Ryan [mailto:[EMAIL PROTECTED] Sent: Wednesday, January 07, 2004 7:15 PM To: Multiple recipients of list ORACLE-L Subject: Re: Suggestions Needed: Latch free - library cache how do you limit excessive soft parsing? ----- Original Message ----- From: Bobak, Mark To: Multiple recipients of list ORACLE-L Sent: Wednesday, January 07, 2004 5:59 PM Subject: RE: Suggestions Needed: Latch free - library cache Tracy,   What Oracle version?  If you're not patched up to the latest patchset for your release, it's always a good idea to do so, as library cache bugs seem to invariably appear in every release.   Has your code changed recently?  Has your usage increased recently?   Finally, library cache latch contention can be a sign of excessive soft parsing (hard parsing usually causes more shared pool latch contention).  Do you have session_cached_cursors set?   Just some thoughts....   -Mark     Mark J. Bobak Oracle DBA ProQuest Company Ann Arbor, MI "Imagination was given to man to compensate him for what he is not, and a sense of humor was provided to console him for what he is."  --Unknown -----Original Message----- From: Tracy Rahmlow [mailto:[EMAIL PROTECTED] Sent: Wednesday, January 07, 2004 5:40 PM To: Multiple recipients of list ORACLE-L Subject: Suggestions Needed: Latch free - library cache We have experienced intermittent problems (slow response time) with our oltp database today.  There appears to be a large number of latch free events and the p2 parameter is indicating an issue with the library cache.  Any thoughts on where to go next? American Express made the following annotations on 01/07/2004 03:36:25 PM ------------------------------------------------------------------------------ ****************************************************************************** "This message and any attachments are solely for the intended recipient and may contain confidential or privileged information. If you are not the intended recipient, any disclosure, copying, use, or distribution of the information included in this message and any attachments is prohibited. If you have received this communication in error, please notify us by reply e-mail and immediately and permanently delete this message and any attachments. Thank you." ****************************************************************************** ==============================================================================