Re: TRUNCATE TABLE acquire rollback segment?

Jonathan Lewis wrote:
>
> The TRUNCATE command has to update the
> segment header block, and several data
> dictionary tables in a self-consistent way
> through a recursive transaction
> e.g.
> update tab$
> update seg$
> update obj$
>
> Possibly insert/update/delete on fet$ and uet$,
> Possibly update tsq$.
>
> and no doubt a few others that I've forgotten about
> at the moment, such as items relating to snapshots
> and snapshot logs.
>
> Rollback is used to protect the integrity of this
> recursive transaction.
>
> --
> Jonathan Lewis
> Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk
>

Now I see how to examine this as a non-guru:

run in archivelog mode.
install LogMiner.
switch logfile
run truncate command
switch logfile
find the logfile just archived

run the logminer proc to examine the recently generated logfile. You'll see all of the (including recursive) DDL/DML that was executed to accomplish the change.

saw it at IOUG - Joe Testa gave a great presentation on the LogMiner 101.
didn't see the advanced presentation.

the paper should be at the IOUG site at http://www.ioug.org

have fun,

Paul Received on Thu May 03 2001 - 21:00:57 CDT