Joe Conway <m...@joeconway.com> writes: > On 5/21/19 3:55 PM, Tom Lane wrote: >> Are you suggesting that we should set stawidth to zero even for a >> fixed-width datatype? That seems pretty silly. We know exactly what >> the value should be, and would be if we'd chanced to find even one >> non-null entry.
> Well you could argue in similar fashion for variable width values -- if > we find even one of those, it will be at least 4 bytes. So why set those > to zero? Um, really the minimum width is 1 byte, given short headers. But as the code notes, zero means we don't know what a sane estimate would be, which is certainly not the case for fixed-width types. regards, tom lane