Re: RES: Creating a new type

[Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>]

"Rodrigo Sakai" <rodrigo(dot)sakai(at)zanthus(dot)com(dot)br> writes:
>   So, I have to guarantee that this situation doesn't occur! But I don't
> want to use triggers because this check must be done on almost all tables
> that uses the type:

The fact that you don't want to do it doesn't make it the wrong
solution ;-)

At the moment there is no other way than a trigger.  There's been some
speculation about whether GIST indexes could be extended to enforce
conditions like "no overlapping values in this column" (as a
generalization of the concept of unique indexes).  No one's tried to
make that happen, though.

BTW, you might want to look at the "timetravel" code in contrib/spi/
... it's a tad old and crufty, but it sounds like you are trying to do
something pretty similar to that.

			regards, tom lane