Re: Enterprise Manager warns of blocking on LGWR

From: Mladen Gogala <>
Date: Thu, 7 Dec 2017 21:52:58 -0500
Message-ID: <>

On 12/07/2017 04:18 PM, Mark W. Farnham wrote:
> There are a few  avenues of research to discover why LGWR might be
> identified as blocking.
By far the most frequent cause of the problems with LGWR are too small log files. I have once seen a customer which had 3 checkpoints per minute. Of course, redo log files were 50M in size. Furthermore, duplexing redo logs is completely unnecessary. Duplexing is done by the storage (RAID 1+0 or some other form of RAID) and it is unnecessary to waste the expensive server CPU and IO capacity to do the job that storage does anyway.

Also, it would help to know which exact event are the processes blocked by LGWR waiting on.


Mladen Gogala
Oracle DBA

Received on Fri Dec 08 2017 - 03:52:58 CET

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