> On Mar 11, 2015, at 10:01 AM, Vladimir Sitnikov <[email protected]> > wrote: > > Those "cost_multiplier" tricks are sloppy.
Maybe, but I actually think "cost multiplier tricks" are better than the alternatives. When faced with two relational expressions that have different calling conventions but are otherwise the same, which do you prefer? Informally, we would choose the one with the "more efficient convention". Associating a cost multiplier with each trait (e.g. Enumerable = 1, Jdbc = 0.8) allows us to achieve this fairly simply. Julian
