Re: log_duration is redundant, no?

Bruce Momjian <bruce(at)momjian(dot)us> writes:
> Well, except for bind, all the log output display is zero cost, just a
> printf(), as I remember. The only cost that is significant, I think, is
> the timing of the query, and that is happening for all the setttings
> discussed.

On a machine with slow gettimeofday(), measuring duration at all is
going to hurt, but apparently that is not Guillaume's situation ---
what's costing him is sheer log volume. And remember that the
slow-gettimeofday problem exists mainly on cheap PCs, not server-grade
hardware. Based on his experience I'm prepared to believe that there
is a use-case for logging just the duration for short queries.

It seems like we should either remove the separate log_duration boolean
or make it work as he suggests. I'm leaning to the second answer now.
What's your vote?

regards, tom lane