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RE: Block dump - Uncommitted TXN - Help Urgent

From: Christian Antognini <Christian.Antognini_at_trivadis.com>
Date: Thu, 21 Sep 2006 17:03:21 +0200
Message-ID: <F2C9CCA71510B442AF71446CAE8AEBAF615A46@MSXVS04.trivadis.com>

Hi  

> Yes I saw Request=4 for quite a few sessions. I ahve Identified the
> Tables that needs INITRANS Bump. Is there a way to figureout how
> much should I bump for each table in question

If you really experience ITL waits I'm not aware of THE method to correctly size these stuffs... I'll probably do it in this way...

  1. I would find out if the problem is due to MAXTRANS or to free space. In fact Oracle should dynamically allocate additional ITL slots if necessary, provided you have free space in the blocks *and* MAXTRANS has not been reached.

2a) If the problem is MAXTRANS, i.e. if the number of ITL slots has not been (unnecessarily) limited, then there are two possibilities:

If there are few ITL waits (few means that the ratio between the number of DML and the waits is small, e.g. few percent) the former is probably better.
If there are lots of ITL waits, i.e. INITRANS is way too small, the latter is probably better.

2b) If the problem is free space, then there are two possibilities:

To choose between these two the same method as before can be used.

Note: IMHO is often better to set MAXTRANS to a high value and increase PCTFREE of 1 or 2 percent instead of setting INITRANS to very high values.

HTH
Chris

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Received on Thu Sep 21 2006 - 10:03:21 CDT

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