Tom Lane escribió: > Sergey Konoplev <gray...@gmail.com> writes: > > On Thu, Oct 11, 2012 at 12:19 PM, Sahagian, David > > <david.sahag...@emc.com> wrote: > >> Are there any "extra" costs to logging all this cool stuff ? > >> > >> log_line_prefix = '%m %a %u %p %c %m %v %x' > > > The formatting cost only but it is so insignificant that does not > > worth bothering with it. > > IIRC, %m would imply a gettimeofday call, which might be expensive > depending on your OS and hardware. I think all the other info is > "just sitting around", though.
Yeah, and having two %m means two gettimeofday calls. Also, %c sort of implies %p, so having both is probably just a waste. One other point is that it's probably a good idea to put in a %q in there so that processes that don't have things like %v, %x don't have to print a bunch of zeros (and also to prevent %a, %u from adding spaces unnecessarily). -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
