> > You might consider whether you can write 'spa-000'::uid explicitly in your > query; that results in immediate application of the domain coercion, so > that the planner no longer sees that as a run-time operation it has to > avoid. >
I should have mentioned that I tried an explicit cast and found that 'spa-000' and 'spa-000'::uid produce identical results. As far as I can tell, there is *no* way to get the planner to constant-fold in this case without using prepared statements. > It's tempting to wonder whether we could somehow constant-fold > CoerceToDomain, at least in the estimation case, but I'm afraid that > would lead to domain constraint failures that would not necessarily occur > at runtime. Or we could skip the domain check for estimation purposes, > but then we're possibly feeding a value that fails the domain check to a > function that might not work right under such conditions. So on the > whole I'm afraid to monkey with that decision. OK, I can see how that makes sense. But shouldn't an explicit cast still work?
