Andres,
If I understand your solution correctly, though, this doesn't really
help the pathological case for freezing, which is the time-oriented
append-only table. For data which isn't being used, allvisible won't be
set either because it won't have been read, no? Is it still cheaper to
set allvisible than vacuum freeze even in that case?
Don't get me wrong, I'm in favor of this if it fixes the other (more
common) cases. I just want to be clear on the limitations.
--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com