On Mon, Aug 27, 2012 at 12:39:02PM -0400, Robert Haas wrote: > On Sat, Aug 25, 2012 at 10:48 PM, Bruce Momjian <br...@momjian.us> wrote: > > On Mon, Aug 20, 2012 at 03:11:51PM -0400, Robert Haas wrote: > >> On Thu, Aug 16, 2012 at 10:28 PM, Bruce Momjian <br...@momjian.us> wrote: > >> > FYI, I am planning to go ahead and package this tool in /contrib for PG > >> > 9.3. > >> > >> Isn't this exactly what we already did, in 9.2, in the form of > >> contrib/pg_test_timing? > > > > Sorry, not sure how I missed that commit. Anyway, I am attaching a > > patch for 9.3 that I think improves the output of the tool, plus adds > > some C comments. > > > > The new output has the lowest duration times first: > > > > Testing timing overhead for 3 seconds. > > Per loop time including overhead: 41.31 nsec > > Histogram of timing durations: > > < usec % of total count > > 1 95.87135 69627856 > > 2 4.12759 2997719 > > 4 0.00086 628 > > 8 0.00018 133 > > 16 0.00001 5 > > 32 0.00000 1 > > > > This should make the output clearer to eyeball for problems --- a good > > timing has a high percentage on the first line, rather than on the last > > line. > > I guess I'm not sure the output format is an improvement. I wouldn't > care much one way or the other if we had made this change at the time > in AS92, but I'm not sure it's really worth breaking compatibility for > a format that may or may not be any better. The person who wrote the > original code presumably preferred it way it already is.
He wrote it that way to allow for simpler C code --- he could just start from 31 and keeping skipping entries until he hit a non-zero. My format makes it easy to see which line should have the majority of the entries, e.g. first line should be > 90%. I doubt there are enough people running this cross-version that consistency in output makes any difference between major PG versions. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
