My guess is that the reason we run ANALYZE more frequently than vacuum
(with the default settings) is that ANALYZE is pretty cheap. In many
cases, if the statistical distribution of the data hasn't changed
much, then it's not really necessary, but it doesn't cost much either.
And for
Josh Berkus escribió:
#autovacuum_vacuum_scale_factor = 0.2
This is set because in my experience, 20% bloat is about the level at
which bloat starts affecting performance; thus, we want to vacuum at
that level but not sooner. This does mean that very large tables which
never have more
