Tomas Vondra <tomas.von...@enterprisedb.com> writes: > Or perhaps what if we have a function that quickly determines if the > attribute has MCV, without loading it? I'd bet the expensive part of > get_attstatslot() is the deconstruct_array(). > We could have a function that only does the first small loop over slots, > and returns true/false if we have a slot of the requested stakind.
Yeah, I like this idea. > It might even check the isunique flag first, to make it more convenient. That would tie it to this one use-case, which doesn't seem advisable. I think we should forget the known-unique angle and just do quick checks to see if both sides have MCVs. regards, tom lane