Re: why aren't ORA-1555 errors MORE frequent?

"Richard Kuhler" <noone_at_nowhere.com> wrote in message news:uOvC9.14875$2z1.6153644_at_twister.socal.rr.com...
> Richard Foote wrote:
>
> <snip>
>
> > ... Oracle takes note of the latest SCN that it
> > could reconstruct in the header (lets say 1100). Therefore, we know *for
> > sure* as the query SCN snapshot is 1234, all changes made to the block
> > *must* have been committed prior to 1100. We don't know when the change
was
> > committed, but it must have been committed prior to 1100.
>
> Thanks, that's the piece of information I was missing.
>
> <snip>
>
> > However, if the query started again at 1234 but there are heaps and
heaps of
> > cleanouts occurring on this table during the running of the query
resulting
> > in heaps and heaps of changes to the RBS then it could be these
*current*
> > cleanouts that are causing the problems.
>
> Interesting. You're saying that the cleanouts themselves have to be
> written to a RBS? I can't envision any reason for this. Why is this
> done? This also seems to imply that a pure SELECT could run out of
> rollback, right?

You can certainly get 1555s when no-one is doing anything other than pure selects, true enough. They are incredibly hard to demonstrate, however, being as rare as hen's teeth.

Regards
HJR
>
>
> Thanks,
> Richard Kuhler
>
Received on Tue Nov 19 2002 - 13:15:02 CST