v$latch_misses statistics

From: Amir Hameed <Amir.Hameed_at_usa.xerox.com>
Date: 25 Mar 2003 08:26:49 -0800
Message-ID: <334de71f.0303250826.35cdf776@posting.google.com>

Hi folks,
I am trying to understand the statistics in this view. I am particularly interested in the statistics related to "libarary cache" and "longop free list" latches. What's happening is that at a particular interval of time, the database is showing high values for the following:

                                                 SLEEP   WAITER   LONG
                                                 SLEEP   SLEEP    HOLD
PARENT NAME    WHERE                             COUNT   COUNT

COUNT
-------------- --------------------------------- ------- -------

library cache  kglget: child: KGLDSBRD                20     114     
14
library cache  kglhdgc: child:                        48      82     
18
library cache  kglhdgn: child:                     1,156  17,809    
615
library cache  kglidp: parent                        451       2    
411
library cache  kgllkdl: child: cleanup             1,655     119  
1,479
library cache  kglpnal: child: alloc space           400     643    
194
library cache  kglpnal: child: before processing      58     762     
28
library cache  kglpnal: parent held, no purge      3,006       3  
1,904
library cache  kglpnc: child                          50  24,449     
24
library cache  kglpndl: parent: purge             47,568     232 
45,818
library cache  kglupc: child                          30   3,635     
19
longop free list ksuloget                            2,370   2,371

The "NWFAIL_COUNT" statistic for these latches is "0". Could anyone please help me understand how to interpret these so that I can get to the root cause. This may be internal Oracle information as I did not find anything on Metalink, ixora, hotsos, jlcomp, etc. When this happens, one particular child library cache latch (#6) reports the highest number of sleeps.

regards
Amir Received on Tue Mar 25 2003 - 10:26:49 CST