Re: what's xidsql and ubasqn in v$transaction?

Thanks, great answer!

xidsqn can be used to identify the unique transaction. what ubasqn is
used for?

Jonathan Lewis wrote:
The slots in the transaction table in the undo segment header
are continuously being reused. Each time a slot it re-used,
its sequence number (xidsqn) goes up.

Similarly, undo blocks are re-used (though it takes more
time to get round to re-using them than transaction slots).
Each time an undo block is "newed" and reused, its
sequence number UBASQN goes up.



--
Regards

Jonathan Lewis
http://www.oracle.com/technology/community/oracle_ace/ace1.html#lewis

The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html

Cost Based Oracle: Fundamentals
http://www.jlcomp.demon.co.uk/cbo_book/ind_book.html


<niy38@xxxxxxxxxxx> wrote in message
news:1149016152.331841.200160@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
XIDSQN Wrap of the entry
UBASQN Sequence no of last entry

don't understand what that mean.


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