Re: Removing more vacuumlazy.c special cases, relfrozenxid optimizations

On Thu, Jan 20, 2022 at 11:45 AM Peter Geoghegan <pg(at)bowt(dot)ie> wrote:
> My thinking on vacuum_freeze_min_age has shifted very slightly. I now
> think that I'll probably need to keep it around, just so things like
> VACUUM FREEZE (which sets vacuum_freeze_min_age to 0 internally)
> continue to work. So maybe its default should be changed to -1, which
> is interpreted as "whatever autovacuum_freeze_max_age/2 is". But it
> should still be greatly deemphasized in user docs.

I like that better, because it lets us retain an escape valve in case
we should need it. I suggest that the documentation should say things
like "The default is believed to be suitable for most use cases" or
"We are not aware of a reason to change the default" rather than
something like "There is almost certainly no good reason to change
this" or "What kind of idiot are you, anyway?" :-)

--
Robert Haas
EDB: http://www.enterprisedb.com