Re: Factoring where clauses through unions

On Friday April 4 2003 4:41, Tom Lane wrote:
> "Ed L." <pgsql(at)bluepolka(dot)net> writes:
> > On Friday April 4 2003 1:42, Jonathan Bartlett wrote:
> >> I have a view that is based on several UNION clauses. I'm wondering,
> >> if I select data from there, will it UNION first, and then apply my
> >> where clauses, or can it factor my where clauses through the UNION?
> >> If it doesn't do it automatically, is there any way to automate it?
> >
> > For cases like this, you can usually construct a very simple test to
> > get the answer.
>
> A test case would tell him what the version he tests does. It would not
> likely inform him that 7.3 will push down such conditions but prior
> versions don't ...

Can you provide a simple example of this change between 7.2.x and 7.3?

Ed