On Sat, Oct 12, 2019 at 8:45 PM Amit Kapila <amit.kapil...@gmail.com> wrote: > > On Sat, Oct 12, 2019 at 10:49 AM Masahiko Sawada <sawada.m...@gmail.com> > wrote: > > > > On Fri, Oct 11, 2019 at 5:13 PM Amit Kapila <amit.kapil...@gmail.com> wrote: > > > > > > That's right, but OTOH, if the user specifies gin_pending_list_limit > > > as an option during Create Index with a value greater than GUC > > > gin_pending_list_limit, then also we will face the same problem. It > > > seems to me that we haven't thought enough on memory usage during Gin > > > pending list cleanup and I don't want to independently make a decision > > > to change it. So unless the original author/committer or some other > > > people who have worked in this area share their opinion, we can leave > > > it as it is and make a parallel vacuum patch adapt to it. > > > > Yeah I totally agreed. > > > > Apart from the GIN problem can we discuss whether need to change the > > current memory usage policy of parallel utility command described in > > the doc? We cannot control the memory usage in index AM after all but > > we need to generically consider how much memory is used during > > parallel vacuum. > > > > Do you mean to say change the docs for a parallel vacuum patch in this > regard? If so, I think we might want to do something for > maintenance_work_mem for parallel vacuum as described in one of the > emails above [1] and then change the docs accordingly. >
Yes agreed. I thought that we can discuss that while waiting for other opinion on the memory usage of gin index's pending list cleanup. For example one of your suggestions[1] is simple and maybe acceptable but I guess that it can deal with only gin indexes but not other index AMs that might consume more memory. [1] https://www.postgresql.org/message-id/CAA4eK1JhpNsTiHj%2BJOy3N8uCGyTBMH8xDhUEtBw8ZeCAPRGp6Q%40mail.gmail.com Regards, -- Masahiko Sawada
