Re: SCN; rollback-segment

Could you clarify the intent of your question:

The rollback segment header has a list of transaction slots and a control block - the control block has an SCN which in some ways is 'the oldest in the segment', but this is not the oldest SCN to which data can be rolled back by applying rollback, as rollback records can contain SCNs which will be written back to data block clones if a read-consistent image is required.

However, the fact that such an SCN exist does not mean that the data as a whole can go back to that SCN, it merely means that it may be possible to roll a very specific bit of the data back to that SCN.

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

Practical Oracle 8i:  Building Efficient Databases
Publishers:  Addison-Wesley

Reviews at: http://www.jlcomp.demon.co.uk/book_rev.html



J. Berger wrote in message <9e3vld$can$07$1_at_news.t-online.com>...


>Hi,

>Is it possible to see the oldest system change number which is available in

>an

>rollback -segment?

>

>Jai

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