Sandra, have you checked the plan of "select for update"?
Is it the same as on old server?
Could you show ASH report for this period?
On Mon, Apr 13, 2015 at 8:14 PM, Sandra Becker <sbecker6925@xxxxxxxxx>
wrote:
Several waits:
EVENT ROW_CNT
----------------------------------- ----------------
db file sequential read 7,714
enq: PR - contention 551
latch free 11,020
log file sync 96,425
read by other session 7,163
On Mon, Apr 13, 2015 at 10:53 AM, Mladen Gogala <
dmarc-noreply@xxxxxxxxxxxxx> wrote:
On 04/13/2015 12:25 PM, Sandra Becker wrote:
Oracle 11.2.0.2
Solaris 10 64-bit on Oracle T5
EMC storage (fast cache enabled)
Last Wednesday night we moved a production database to new hardware. We
do not have the option to move it back. On Friday we started experiencing
severe performance issues. ASH reports show the "SELECT...FOR UPDATE
WAIT..." running as the top SQL for events and row sources. This is NOT
new code. What can I look at, is there anything I can do, short of killilng
sessions, to get this under control? I'm opening a ticket with Oracle, but
this forum generally responds faster.
I'm not really familiar with how the SELECT FOR UPDATE WAIT works and
haven't found a good explanation yet. The select is on a partitioned
table. Does it lock only a row or does it lock the partition? At times I
can see a dozen or more of these statements running. Once they complete, I
then see a lot of waits on log file sync.
If anyone knows, how does having fast-cache enabled affect this?
Thanks for any suggestions/guidance.
--
Sandy
GHX
Hi Sandra,
What event exactly are your sessions waiting on?
Regards,
--
Mladen Gogala
Oracle DBA
http://mgogala.freehostia.com
--
//www.freelists.org/webpage/oracle-l
--
Sandy
GHX
