My understanding is that this is caused by parsing the same statement multiple
times, i.e. cursors not sharing. You need to try and figure out the reason. I
just wrote a blog post about this – see
http://people.ds.cam.ac.uk/psh35/blog/post/parsing/. I found Carlos Sierras ;
script (linked from the post) really helpful as you see.
Check that you aren’t encountering bug 20476175 if you are 12CR1.
I have just ventured into blogging by the way, and would welcome any
constructive criticism. Please email me directly with that.
I hope this helps.
Paul Houghton
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Stefan Knecht
Sent: 19 December 2017 06:39
To: dmarc-noreply@xxxxxxxxxxxxx
Cc: Oracle-L Freelists <oracle-l@xxxxxxxxxxxxx>
Subject: Re: Cusror: Pin S wait in X
More details are needed to give you any kind of specific answer:
- What Oracle version exactly?
- What are these sessions running? (Query + Plan)
- Does the query run in parallel?
- Does the query use bind variables?
- You can also look in x$mutex_sleep to see the most active mutexes (it's
likely Cursor Pin but might be something else on the off chance). Snap it a few
times and compare to see what's actively being used right now.
Stefan
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On Tue, Dec 19, 2017 at 4:59 AM, Sanjay Mishra
<dmarc-noreply@xxxxxxxxxxxxx<mailto:dmarc-noreply@xxxxxxxxxxxxx>> wrote:
Can some one suggest what can be done to stop these wait as it coming as
topmost event for multiple SID ? I tried to following 786507.1 doc to identify
the session but if I kill one session another one comes up. I even bounced the
Instance one by one but this still continues. Any suggestion as else had to
open Oracle ticket due to slowness been reported. Ashtop shows all top 20
listed process with same Waiteven and with one same SQL id
TIA
Sanjay
