On Tue, Mar 26, 2019 at 5:46 PM Tomas Vondra <tomas.von...@2ndquadrant.com> wrote:
> On Tue, Mar 26, 2019 at 03:06:52PM +0300, Surafel Temesgen wrote: > >On Thu, Feb 28, 2019 at 11:16 PM Tomas Vondra < > tomas.von...@2ndquadrant.com> > >wrote: > > > >> > >> To give you a (admittedly, somewhat contrived and artificial example): > >> > >> SELECT * FROM t1 WHERE id IN ( > >> SELECT id FROM t2 ORDER BY x FETCH FIRST 10 PERCENT ROWS ONLY > >> ); > >> > >> Maybe this example is bogus and/or does not really matter in practice. I > >> don't know, but I've been unable to convince myself that's the case. > > > > > >does this means we abandon incremental approach? and am not sure of > >calculating > >percentage after OFFSET clause is acceptable or not > > > > I don't follow. I don't think I've suggested to abandon the incremental > approach - I've explained why I think it's what the patch should be doing, > and illustrated that with an example. > but it is more complex than the previous approach and it will be more complex in starting calculating percentage before offset row count. Doesn't simplicity prefer? regards Surafel
