Re: To find out the Top process or Top User sessions generating highest number of archive logs

From: Jeremiah Wilton <>
Date: Thu, 16 Feb 2012 12:12:32 -0700
Message-Id: <>

On Feb 16, 2012, at 11:27 AM, Powell, Mark wrote:

> I note that the query below always seems to return smon as the largest redo generator on the couple of systems where I checked so if you are interested in only user sessions you might want to add "and s.username is not null" as a condition to filter out the Oracle rdbms background sessions.

I don't see a good reason to exclude background processes, especially if one choses to sample and delta the redo size over a number of samples. What if one of them is somehow generating the large amount of redo that the I am trying to track down?

If you do choose to exclude background processes, there's a column for that in gv$session. Just select where type != 'BACKGROUND'.

Another trick to avoid doing deltas (why are we avoiding that when we have Tanel's snapper handy?) might be to divide the redo size by the length of time the session has been logged in. That way you get sort of redo size per unit time figure, instead of the grand total for the lifetime of the session (which is what is making SMON look so large).


Jeremiah Wilton
Remote DBA Services

Received on Thu Feb 16 2012 - 13:12:32 CST

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