On 1/18/22, 9:47 PM, "Masahiko Sawada" <sawada.m...@gmail.com> wrote: > IIUC what we want to do here are two things: (1) select only old > tables and (2) set INDEX_CLEANUP = off, TRUNCATE = off, and FREEZE = > on. VACUUM LIMIT statement does both things at the same time. Although > I’m concerned a bit about its flexibility, it’s a reasonable solution. > > On the other hand, it’s probably also useful to do either one thing in > some cases. For instance, having a selector for (1) would be useful, > and having a new option like FAST_FREEZE for (2) would also be useful. > Given there is already a way for (2) (it does not default though), I > think it might also be a good start inventing something for (1). For > instance, a selector for VACUUM statement I came up with is: > > VACUUM (verbose on) TABLES WITH (min_xid_age = 1600000000); > or > VACUUM (verbose on) TABLES WITH (min_age = failsafe_limit); > > We can expand it in the future to select tables by, for example, dead > tuple ratio, size, etc. > > It's a random thought but maybe worth considering.
That's an interesting idea. A separate selector clause could also allow users to choose how they interacted (e.g., should the options be OR'd or AND'd). Nathan
