On Mon, Apr 13, 2020 at 4:23 PM Masahiko Sawada <masahiko.saw...@2ndquadrant.com> wrote: > > On Mon, 13 Apr 2020 at 18:25, Amit Kapila <amit.kapil...@gmail.com> wrote: > > > > On Fri, Apr 10, 2020 at 7:05 PM Justin Pryzby <pry...@telsasoft.com> wrote: > > > > > > > > > No problem. I think I was trying to make my text similar to that from > > > 14a4f6f37. > > > > > > I realized that I didn't sq!uash my last patch, so it didn't include the > > > functional change (which is maybe what Robert was referring to). > > > > > > > I think it is better to add a new test for temporary table which has > > less data. We don't want to increase test timings to test the > > combination of options. I changed that in the attached patch. I will > > commit this tomorrow unless you or anyone else has any more comments. > > > > Thank you for updating the patch! > > I think we can update the documentation as well. Currently, the > documentation says "This option can't be used with the FULL option." > but we can say instead, for example, "VACUUM FULL can't use parallel > vacuum.". >
I am not very sure about this. I don't think the current text is wrong especially when you see the value we can specify there is described as: "Specifies a non-negative integer value passed to the selected option.". However, we can consider changing it if others also think the proposed text or something like that is better than current text. > Also, I'm concerned that the documentation says that VACUUM FULL > cannot use parallel vacuum and we compute the parallel degree when > PARALLEL option is omitted, but the following command is accepted: > > postgres(1:55514)=# vacuum (full on) test; > VACUUM > > Instead, we can say: > > In plain VACUUM (without FULL), if the PARALLEL option is omitted, > then VACUUM decides the number of workers based on the number of > indexes that support parallel vacuum operation on the relation which > is further limited by max_parallel_maintenance_workers. > > (it just adds "In plain VACUUM (without FULL)" to the beginning of the > original sentence.) > Yeah, something on these lines would be a good idea. Note that, we are already planning to slightly change this particular sentence in another patch [1]. [1] - https://www.postgresql.org/message-id/20200322021801.GB2563%40telsasoft.com -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
