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Re: Lots of "log file sync" waits and nothing else on inserts and commits

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Wed, 28 Jan 2004 22:17:51 +0000 (UTC)
Message-ID: <bv9cef$bls$1@sparta.btinternet.com>

You have v$session_event for SID = 23.
The only session that does log file writes is LGWR - which usually has a SID around
4 or 5

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"Bobby Durrett" <bdurrettccci_at_yahoo.com> wrote in message
news:8c63eb2b.0401281343.58e92404_at_posting.google.com...

> I'm really puzzled. Check out the session event stats for my session
> below.
>
> According to Note 223117.1 from Metalink, if you have a bunch of "log
> file sync" waits, and not as many "log file parallel write" waits then
> the problem is not I/O on the redo logs.
>
> In this operation, which is all inserts and commits, we have tons of
> log file syncs, small cpu (not reflected below, but true) and no log
> file parallel write waits.
>
> Any ideas?
>
> - Bobby
>
> 1* select event,time_waited from v$session_event where sid=23
> SQL> /
>
> EVENT TIME_WAITED
> ------------------------------------------------------ -----------
> latch 4
> free buffer waits 10047
> buffer busy 5
> log buffer space 15324
> log file switch completion 232
> log file sync 388300
> db file sequential read 4536
> db file scattered read 3696
> db file parallel read 0
> direct path read 5
> direct path write 6067
> undo segment extension 0
> SQL*Net message to client 18
> SQL*Net message from client 59222
> SQL*Net more data from client 173
> SQL*Net break/reset to client 1255
>
> 16 rows selected.
Received on Wed Jan 28 2004 - 16:17:51 CST

Original text of this message

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