Re: Increase the size of rollback segments

I have to disagree with you on this point. In well-structured system, the optimum rollback size is the smallest size that you can get away with that does not result in frequent small extends and shrinks of rollback segments.

However, there are often cases where you expect an occasional , but not predictably timed, transaction to demand an excessive amount of rollback. In this case, the optimum strategy is to set the optimal at the 'steady state' figure, and allow the rollback segment to shrink automatically some time after the major transaction completes.

The only alternatives are to code the transaction to acquire the same rollback segment every time(nasty), or to code the transaction to find and shrink the extended rollback segment as its last step (just as nasty), or get the dba to keep checking the database and shrink the segment manually (nastiest of all).

--

Jonathan Lewis
Yet another Oracle-related web site:  http://www.jlcomp.demon.co.uk

Howard J. Rogers wrote in message <39e7a664$1_at_news.iprimus.com.au>...


>Why avoid dropping them?  There's no point.  Create a new one first, then

>drop the old ones.  Incidentally, Optimal is a very bad idea (it will cause

>shrinking just exactly when you don't want it to happen: when a new

>transaction is looking to acquire new rollback blocks).

>

 


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