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Re: Very high 'log file sync' wait time with no 'log file parallel write' wait time

From: Charles Hooper <hooperc2000_at_yahoo.com>
Date: 27 Nov 2006 04:54:08 -0800
Message-ID: <1164632048.892638.183480@l39g2000cwd.googlegroups.com>


mccmx_at_hotmail.com wrote:
> > Matt, how big is your log buffer? Log writer will write
>
> 2Mb
>
> > 1) Every 3 seconds
>
> We commited over 170,000 times in the space of a few minutes..:
>
> Execute 179,802 4.90 474.73 0 0 0
>
> > 2) When there is more then 1M in log buffer
>
> The average row length of the table is only 200 bytes
>
> > 3) When your log buffer is more then 1/3 full
>
> The average row length of the table is only 200 bytes
>
> > 4) When "commit" is issued.
>
> It looks like the database is issuing the commit command for every row
> - but we are not using any of the datatypes which force this behaviour
> (e.g. LOBs etc)
>
> Matt

Why are you specifying "commit=y" for imp? If you set commit=n, a commit will be performed after each object is fully imported, rather than after the number of rows that will fit into the buffer (buffer=20000000 specification) The special cases outlined by Steve Howard still apply.

See:
http://asktom.oracle.com/pls/ask/f?p=4950:8:::::F4950_P8_DISPLAYID:10094378836151

Charles Hooper
PC Support Specialist
K&M Machine-Fabricating, Inc. Received on Mon Nov 27 2006 - 06:54:08 CST

Original text of this message

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