On 2014-01-06 20:51:57 -0500, Robert Haas wrote: > On Mon, Jan 6, 2014 at 7:50 PM, Jim Nasby <j...@nasby.net> wrote: > > On 1/4/14, 8:19 AM, Robert Haas wrote: > >> Also, while multixactid_freeze_min_age should be low, perhaps a > >> million as you suggest, multixactid_freeze_table_age should NOT be > >> lowered to 3 million or anything like it. If you do that, people who > >> are actually doing lots of row locking will start getting many more > >> full-table scans. We want to avoid that at all cost. I'd probably > >> make the default the same as for vacuum_freeze_table_age, so that > >> mxids only cause extra full-table scans if they're being used more > >> quickly than xids. > > > > Same default as vacuum_freeze_table_age, or default TO > > vacuum_freeze_table_age? I'm thinking the latter makes more sense... > > Same default. I think it's a mistake to keep leading people to think > that the sensible values for one set of parameters are somehow related > to a sensible set of values for the other set. They're really quite > different things.
Valid argument - on the other hand, defaulting to the current variable's value has the advantage of being less likely to cause pain when doing a minor version upgrade because suddenly full table vacuums are much more frequent. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
