On Wed, Dec 19, 2018 at 6:36 AM Tom Lane <t...@sss.pgh.pa.us> wrote: > I don't really find it "natural" for equality to consider obviously > distinct values to be equal.
The Unicode consortium calls our current behavior within comparisons "deterministic comparisons" -- it's something they're not so keen on: https://unicode.org/reports/tr10/#Deterministic_Comparison I suggest using their terminology for our current behavior. I can see where Peter was coming from with "natural", but it doesn't quite work. One problem with that terminology is that already refers to a sort that sorts numbers as numbers. How about "linguistic", or "lexical"? There is a significant cultural dimension to this. I suspect that you don't find it "natural" that obviously distinct values compare as equal because you're anglophone. That's the exact behavior you'll get when using an unadorned en_US collation/locale, I think. > As a counterexample, the fact that IEEE > arithmetic treats 0 and -0 as equal seems to cause about as many problems > as it solves, and newcomers to float math certainly don't find it > "natural". So I object to that particular naming. FWIW, I don't think that your IEEE analogy quite works, because you're talking about a property of a datatype. A collation is not intrinsic to any collatable datatype. Fortunately, we're not required to agree on what feels natural. -- Peter Geoghegan
