Hi Steve, yes, you're absolutely right. I've inhereted that system. The shared_pool_size = 750M. I believe it's HUGE and oversized. The application code is mostly based on literal SQL. The miss rate on the shared pool is normally about 15%-20% with periodical peaks up to 50%. But the previous DBA insist that we shouldn't decrease the size of shared pool as the miss rate will be much higher. He also setup periodical flushing every 3 hours (I assume he did it in order to prevent ORA-4031). If I undestand the things right, deacresing of shared_pool_size will decrease load on shared pool latch _but_ contention on the library latches will be higher because of higher parse rate. Is it correct and what's your advice in my case?
Thanks in advance, Ed > Hi Ed, > > I would agree with the _kgl_latch_count change, but the _kgl_bucket_count change seems unwarranted and extreme. Rather I > suspect that the size of your library cache hash table rather reflects an oversized shared pool, probably with some use > of literal SQL. > > @ Regards, > @ Steve Adams > @ http://www.ixora.com.au/ - For DBAs > @ http://www.secularislam.org/call.htm - For Muslims > @ http://www.christianity.net.au/ - For all > > > -----Original Message----- > From: Edward Shevtsov [mailto:[EMAIL PROTECTED]] > Sent: Friday, 19 October 2001 18:02 > To: [EMAIL PROTECTED] > Cc: Steve Adams > Subject: Re: distribution of the sleeps on the library cache latches > > > Hi Steve, > > thanks for your reply. I'm thinking about twice increasing number of > library latches ( _kgl_latch_count = 23 ) in order to mitigate loading on > them. > Also I would like to set _kgl_bucket_count = 8 according to output of your > script. Do you think it's a good idea in my case. > > NAME IMPACT SLEEP_RATE HOLDING LEVEL# > ------------------------- ---------- ---------- ---------- ---------- > library cache 60333579.3 0.32% 172945238 5 > shared pool 19313269.2 1.40% 8265405 7 > cache buffers chains 1950080.11 0.00% 629411 1 > row cache objects 738401.912 0.04% 3369329 4 > session allocation 70758.0784 0.01% 144008 5 > cache buffer handles 56104.2222 0.01% 71913 3 > redo allocation 33494.1227 0.02% 215582 6 > cache buffers lru chain 12784.3859 0.00% 198869 3 > checkpoint queue latch10980.4325 0.00% 52259 7 > latch wait list 9976.33016 0.04% 24412 9 > redo writing 4846.5256 0.01% 75484 5 > > Regards, > Ed > -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Edward Shevtsov INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
