> If the problem is that all the freezing happens at once, then ISTM the > solution is to add a random factor. Say, when a tuple just passes the > lower threshold it has a 1% chance of being frozen. The chance grows > until it is 100% as it reaches the upper threshold.
Doesn't have to be random; it could be determinative. That is, we could have a vacuum_freeze_max_size parameter ... and accompanying autovacuum parameter ... which allowed the user to limit freezing scans to, say, 1GB of the table at a time. If I could, say, call a manual freeze of 10% of the largest tables ever night, then I might actually be able to schedule it. It's a full scan of the whole table which is fatal. -- -- Josh Berkus PostgreSQL Experts Inc. http://www.pgexperts.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers