On Friday 20 February 2009 7:57:32 pm decibel wrote:
> On Feb 19, 2009, at 1:49 PM, Adrian Klaver wrote:
> > From the Oracle manual:
> > ENABLE NOVALIDATE means the constraint is checked for new or
> > modified rows, but existing data may violate the constraint.
> >
> > So you are looking for an incomplete constraint?
>
> More likely they want to add a constraint but can't afford the time
> it would take to scan the table while holding an exclusive lock. At
> least that's the situation we're facing at work.
I get it now, basically validate on demand, so the cost is spread out instead of
incurred at the ALTER TABLE command.
>
> FWIW, I've been talking to Command Prompt about developing a fix for
> this, targeting inclusion in 8.5. I think Alvaro and I have come up
> with a reasonably plan, but there hasn't been time to present it to
> the community yet.
--
Adrian Klaver
aklaver@comcast.net