Hello, At Wed, 07 Feb 2018 16:59:20 -0500, Tom Lane <t...@sss.pgh.pa.us> wrote in <3246.1518040...@sss.pgh.pa.us> > Robert Haas <robertmh...@gmail.com> writes: > > It seems to me that there was a thread where Tom proposed removing > > support for dynamic_shared_memory_type = none. > > I think you're recalling <32138.1502675...@sss.pgh.pa.us>, wherein > I pointed out that > > >>> Whether that's worth the trouble is debatable. The current code > >>> in initdb believes that every platform has some type of DSM support > >>> (see choose_dsm_implementation). Nobody's complained about that, > >>> and it certainly works on every buildfarm animal. So for all we know, > >>> dynamic_shared_memory_type = none is broken already. > > (That was in fact in the same thread Kyotaro-san just linked to about > reimplementing the stats collector.) > > It's still true that we've no reason to believe there are any supported > platforms that haven't got some sort of DSM. Performance might be a > different question, of course ... but it's hard to believe that > transferring stats through DSM wouldn't be better than writing them > out to files.
Good to hear. Thanks. > > I suggest we remove support for dynamic_shared_memory_type = none first, > > and see if we get any complaints. If we don't, then future patches can > > rely on it being present. > > If we remove it in v11, it'd still be maybe a year from now before we'd > have much confidence from that alone that nobody cares. I think the lack > of complaints about it in 9.6 and 10 is a more useful data point. So that means that we are assumed to be able to rely on the existence of DSM at the present since over a year we had no complain despite the fact that DSM is silently turned on? And apart from that we are ready to remove 'none' from the options of dynamic_shared_memory_type right now? If I may rely on DSM, fallback stuff would not be required. > regards, tom lane regards, -- Kyotaro Horiguchi NTT Open Source Software Center