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RE: Simple SQL waiting on 'log file sync'

From: Deepak Sharma <sharmakdeep_oracle_at_yahoo.com>
Date: Fri, 18 Nov 2005 10:37:46 -0800 (PST)
Message-ID: <20051118183746.49456.qmail@web52812.mail.yahoo.com>

Makes sense !! Thanks,

BTW, I drilled it down to a 5-column concatenated index (which I forgot to mention earlier) that was on this table. I dropped all index 1 by 1, until I found the above index that was still causing this message. Rebuilding this index took care of it and now the loads are back to normal.

> Deepak,
>
> Ever wonder why a commit normaly on takes a sec or
> less even when you are committing tons of row
> chagnes?
> Because the rows have already changed!...redo,
> rollback, and commit logic.
> All of this has already been logged to the redo (and
> archive) logs just waiting on you to commit or
> rollback (that will take time, the rollback).
>
> You are waiting on redo log files access/time...redo
> contention.
> What until you have a lot of sessions doing this and
> you start having tons of latch wait contention.
>
> Is your db busy today?...my suggestions is tune your
> redo log file (disks).
>
> hth
>
> Chris Marquez
> Oracle DBA
>
>
> -----Original Message-----
> From: oracle-l-bounce_at_freelists.org on behalf of
> Deepak Sharma
> Sent: Fri 11/18/2005 1:17 PM
> To: Kevin Closson
> Cc: oracle-l_at_freelists.org
> Subject: RE: Simple SQL waiting on 'log file sync'
>
> I am in the process of debugging an application that
> uses a PL/SQL procedure that ha sa statement similar
> to this. In my testing, I do have a step to commit,
> but that is 'after' this insert..select statement.
> What I am noticing is that if I run a trace, there
> are
> 'log file sync' messages.
>
> Step1:
> insert.. select statement <<- generated trace has
> the
> log file sync message
>
> Step 2:
> commit <<- I'm not even there yet
>
> Thanks,
> Deepak
>
>
> --- Kevin Closson <kevinc_at_polyserve.com> wrote:
>
> > >>>
> > >>>INSERT INTO A1 SELECT * FROM B1;
> > >>>
> > >>>1) Isn't 'log file sync' related to commits? In
> > above I am
> > >>>not even commiting.
> >
> > um, if you are not committing, what is the purpose
> > of this
> > select ?
> >
> >
>
>
>
>
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Received on Fri Nov 18 2005 - 13:41:18 CST

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