On Wed, 2023-01-25 at 16:26 +1300, David Rowley wrote: > On Wed, 18 Jan 2023 at 22:15, Laurenz Albe <laurenz.a...@cybertec.at> wrote: > > Attached is a new version of my patch that tries to improve the wording. > > I had a look at this and agree that we should adjust the paragraph in > question if people are finding it confusing. > > I started to adjust that but since the text is fairly short it turned > out quite different from what you had. > > I ended up with: > > + With partitioned tables, since these do not directly store tuples, these > + do not require autovacuum to perform any <command>VACUUM</command> > + operations. Autovacuum simply performs a <command>VACUUM</command> on > the > + partitioned table's partitions the same as it does with normal tables. > + However, the same is true for <command>ANALYZE</command> operations, and > + this can be problematic as there are various places in the query planner > + that attempt to make use of table statistics for partitioned tables when > + partitioned tables are queried. For now, you can work around this > problem > + by running a manual <command>ANALYZE</command> command on the partitioned > + table when the partitioned table is first populated, and again whenever > + the distribution of data in its partitions changes significantly. > > which I've also attached in patch form. > > I know there's been a bit of debate on the wording and a few patches, > so I may not be helping. If nobody is against the above, then I don't > mind going ahead with it and backpatching to whichever version this > first applies to. I just felt I wasn't 100% happy with what was being > proposed.
Thanks, your help is welcome. Did you see Justin's wording suggestion in https://postgr.es/m/20230118174919.GA9837%40telsasoft.com ? He didn't attach it as a patch, so you may have missed it. I was pretty happy with that. I think your first sentence it a bit clumsy and might be streamlined to Partitioned tables do not directly store tuples and consequently do not require autovacuum to perform any <command>VACUUM</command> operations. Also, I am a little bit unhappy about 1. Your paragraph states that partitioned table need no autovacuum, but doesn't state unmistakably that they will never be treated by autovacuum. 2. You make a distinction between table partitions and "normal tables", but really there is no distiction. Perhaps I am being needlessly picky here... Yours, Laurenz Albe
