Jim,

> In the web world of 24/7 availability, I can't take my database down for
> more than the few milliseconds to restart a new server version. All
> scheme upgrades must be done with the database running multi-user
> production. I know that batch world was different, but we're not in
> Kansas no more, baby.

What was the reason that you were arguing that metadata changes must not be
transactional some time ago in FB-Architect?

Not that I argue that hot schema upgrade is not possible, but this is not
something I have seen so far (though I agree that being 29 I have not seen
as much as you did).

> It can (and should) be done, but it takes thought, planning, and care.

I have no guideline how to upgrade the running database, but there are few
things that I do not believe:

- there are no planned down time for a single component of the system;

- for the system with the high load like walmart.com there is only single
primary database and there are no chances to take it down.

But again, my real world two years ago was batch processing, since that time
it is a call center of a big insurance company and document workflow
automation of another insurance company. And there are planned down times.

Maybe this does not work for NYSE, no clue, I did not work there.

Roman