On Dec 13, 2007 10:06 PM, Tom Lane <[EMAIL PROTECTED]> wrote: > Andrew Sullivan <[EMAIL PROTECTED]> writes: > > On Fri, Dec 14, 2007 at 01:47:23AM +0000, Gregory Stark wrote: > >> Huh, I was all set to post an example of a useful application of it but > >> then > >> apparently I'm wrong and it doesn't work: > > > I dimly remember some discussion of this issue once before, maybe a year > > ago. My memory isn't what it was, and I can't find it by trolling archives, > > but I recall Tom saying that it was dumb, yes, but don't do that, because > > there's some reason not to change it. I know, helpful search terms R me. > > Hmm ... I don't recall much either. The code in nodeLimit.c just > silently replaces a negative input value by zero. It'd certainly be > possible to make it throw an error instead, but what the downsides of > that might be aren't clear. > > I guess that on purely philosophical grounds, it's not an unreasonable > behavior. For example, "LIMIT n" means "output at most n tuples", > not "output exactly n tuples". So when it outputs no tuples in the face > of a negative limit, it's meeting its spec. If you want to throw an > error for negative limit, shouldn't you logically also throw an error > for limit larger than the actual number of rows produced by the subplan?
for historical record, this comment (subject not directly related to the OP) was probably this: http://www.mail-archive.com/pgsql-hackers@postgresql.org/msg62562.html at least if it happened since 10/2004, which is when i started tracking -hackers in my gmail account (an amazing search tool, btw). merlin ---------------------------(end of broadcast)--------------------------- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate