On Tue, Aug 29, 2006 at 06:17:39AM +1000, Naz Gassiep wrote:
> I would like more information on this deficiency and what causes it so I
> know when to anticipate it. This resulted in a rather nasty bug which
> took me ages to track down. Is anyone able+willing to explain a little
> here or should I ask in -hackers ?
Sure, UNIQUE constraints are not deferrable. With normal constraints
you can defer the check until the end of transaction and be in an
inconsistant state for while. However, PostgreSQL doesn't support this
for uniqueness checks. However, temporary inconsistancy in unique
columns doesn't some up that often so it's not that big a deal.
This has been a problem for a long time and will quite possibly be for
a while still, mainly because no-one really has any idea how to fix
it...
Have a nice day,
--
Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/
> From each according to his ability. To each according to his ability to litigate.
