On Mon, Jul 18, 2022 at 6:43 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > Um ... why is "the order in which the elements were chosen" a concept > we want to expose? ISTM sample() is a black box in which notionally > the decisions could all be made at once.
I agree with that. But I also think it's fine for the elements to be returned in a shuffled order rather than the original order. > > I really think this function needs to grow an algorithm argument that can > > be used to specify stuff like ordering, replacement/without-replacement, > > etc...just some enums separated by commas that can be added to the call. > > I think you might run out of gold paint somewhere around here. I'm > still not totally convinced we should bother with the sample() function > at all, let alone that it needs algorithm variants. At some point we > say to the user "here's a PL, write what you want for yourself". I don't know what gold paint has to do with anything here, but I agree that David's proposal seems to be moving the goalposts a very long way. The thing is, as Martin points out, these functions already exist in a bunch of other systems. For one example I've used myself, see https://underscorejs.org/ I probably wouldn't have called a function to put a list into a random order "shuffle" in a vacuum, but it seems to be common nomenclature these days. I believe that if you don't make reference to Fisher-Yates in the documentation, they kick you out of the cool programmers club. -- Robert Haas EDB: http://www.enterprisedb.com
