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Home -> Community -> Mailing Lists -> Oracle-L -> Cache buffer chains (kslbegin)
Hello,
I have a 10 minute statspack report from a busy time period, and have seen
that buffer busy waits were the highest wait events. Would I be correct to
then look at the Latch Miss Source at the largest sleeps? I have the
following information there:
Latch Sleep breakdown for DB: MERLIN Instance: MERLIN Snaps: 244 -245
-> ordered by misses desc
Get Spin &
Latch Name Requests Misses Sleeps Sleeps
1->4
-------------------------- -------------- ----------- -----------
------------
cache buffers chains 156,103,492 15,773 4,067 0/0/0/0/0
simulator hash latch 5,788,739 604 25
579/25/0/0/0
multiblock read objects 502,619 472 51
421/51/0/0/0
library cache 486,962 409 44
365/44/0/0/0
-------------------------------------------------------------
Latch Miss Sources for DB: MERLIN Instance: MERLIN Snaps: 244 -245
NoWait
Waiter
Latch Name Where Misses Sleeps
Sleeps
------------------------ -------------------------- ------- ---------- -------- cache buffers chains kcbgtcr: kslbegin excl 0 2,439 3,749 cache buffers chains kcbrls: kslbegin 0 973 58 cache buffers chains kcbzib: multi-block read: 0 308 0 cache buffers chains kcbzgb: scan from tail. no 0 199 0
Can anyone confirm what "kslbegin excl" is? I found something listing kslbegin as a "macro to lock a latch", but didn't realise you could lock a latch in anything other than exclusive. With high sleeps on "kslbegin excl", where would be the best place to start digging into what caused these cache buffer chain sleeps?
Many thanks,
Steve.
-- http://www.freelists.org/webpage/oracle-lReceived on Mon Apr 24 2006 - 08:39:23 CDT
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