Re: High waits/Timeouts - log file parallel write
- From: Steve Adams <steve.adams@xxxxxxxxxxxx>
- To: pele_00_2000@xxxxxxxxx
- Date: Tue, 28 Feb 2006 11:56:22 +1100
Hi Tom,
The 'log file parallel write' waits affect LGWR only. They do not affect
the performance of user processes directly (although they do impact
somewhat on your 'log file sync' wait duration). The number of timeouts
is influenced by your use of asynchronous I/O and by how often LGWR is
posted by user processes. It is not a useful indicator of performance
problems.
I think you should be more concerned about the 'control file parallel
write' waits that are probably affecting user processes directly.
@ Regards,
@ Steve Adams
@ http://www.ixora.com.au/ - For DBAs
@ http://www.christianity.net.au/ - For all
TP wrote:
Hello all,
I seeing high Waits, Timeouts from one the
problem instance.
Top 5 Timed Events
~~~~~~~~~~~~~~~~~~
% Total
Event
Waits Time (s) Ela Time
--------------------------------------------
------------ ----------- --------
CPU time
8 40.51
control file parallel write
642 5 25.56
db file sequential read
343 2 9.40
log file parallel write
9,697 2 7.99
log file sync
425 1 5.69
-------------------------------------------------------------
^LWait Events for DB: C3PO Instance: C3PO
[snip]
Avg
Total Wait wait Waits
Event Waits
Timeouts Time (s) (ms) /txn
---------------------------- ------------
---------- ---------- ------ --------
control file parallel write 642
0 5 8 1.4
db file sequential read 343
0 2 6 0.7
log file parallel write 9,697
8,429 2 0 21.1
log file sync 425
0 1 3 0.9
[snip]
-----------------------------------------
It seems like I'm having some issue with the LGWR
"log file parallel write" (timeouts).
Can you suggest and/or provide some
recommendations? The DB version is 9205 on
Solaris 2.9.
Thanks in advance!
Tom
[snip]
--
//www.freelists.org/webpage/oracle-l
Other related posts:
