RE: DBWR pegged out

From: John Hallas <>
Date: Tue, 8 Mar 2011 16:14:57 +0000
Message-ID: <>

From the Ixora site
If the bandwidth is inadequate at any point, you will see free buffer waits. If the bandwidth is lower at the operating system or hardware level than at the Oracle level, then you will see substantial write complete waits. Free buffer waits and write complete waits are opposite types of DBWn problem. Generally, the first indicates that the write bandwidth is too small, and the second indicates that Oracle internal write batch size (_db_block_write_batch) is too big.

In my view this is a problem with writing down to disk and is an OS I/O issue

-----Original Message-----
From: [] On Behalf Of Doug Gernaat Sent: 08 March 2011 15:55
Subject: DBWR pegged out

after oracle suggested bumping up db_writer_processes from 2 to 4, at times it is still getting pegged out. "write complete waits" will become a top time event. drilling down will show:

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Received on Tue Mar 08 2011 - 10:14:57 CST

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