On Mon, 2021-09-06 at 12:11 -0700, Peter Geoghegan wrote: > On Mon, Sep 6, 2021 at 9:21 AM Laurenz Albe <laurenz.albe@xxxxxxxxxxx> wrote: > > #define BYPASS_THRESHOLD_PAGES 0.02 /* i.e. 2% of rel_pages */ > > > > So up to an additional 2% of all pages can have the all-visible bit > > unset with "index_cleanup = auto". > > > > That is probably not worth worrying, right? > > I don't think it's worth worrying about. > > The bypass-index-vacuuming feature may have had a bit of a messaging > problem. It was something we usually talked about as being about > skipping index vacuuming, because that's what it actually does. > However, the feature isn't really about doing less work during VACUUM. > It's actually about doing *more* work during VACUUM -- more useful > work. Especially setting visibility map bits. But also freezing. Now > you can very aggressively tune VACUUM to do these things more often, > with no fear of that being way too expensive because of index > vacuuming that has only marginal value. That makes sense; thanks for the detailed explanation. Yours, Laurenz Albe
