Re: Clamping reulst row number of joins.

* Tom Lane (tgl(at)sss(dot)pgh(dot)pa(dot)us) wrote:
> BTW, is that JOIN (VALUES(...)) thing common in applications, or did you
> just use it to make a compact example? If it were something worth
> optimizing, it seems like we could teach the planner to "pull up VALUES"
> in the same way that it flattens sub-selects. I'm not sure if this is
> worth the trouble or not, though.

I've certainly seen and used values() constructs in joins for a variety
of reasons and I do think it'd be worthwhile for the planner to know how
to pull up a VALUES construct.

Would that be a lot of effort, either code-wise or runtime-wise? My gut
feeling is that it wouldn't be, but you're clearly in a much better
position to determine that.

Thanks!

Stephen