Re: Patch: add timing of buffer I/O requests
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Peter Geoghegan <peter@2ndquadrant.com>, Ants Aasma <ants@cybertec.at>, Greg Smith <greg@2ndquadrant.com>, pgsql-hackers@postgresql.org
Date: 2012-04-25T16:47:28Z
Lists: pgsql-hackers
Robert Haas <robertmhaas@gmail.com> writes: > On Sat, Apr 14, 2012 at 10:33 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote: >> There's no particular reason to think that Moore's Law is going to >> result in an increase in the fractional precision of timing data. >> It hasn't done so in the past, for sure. > Perhaps, but nobody's explained what we gain out of NOT using numeric. > "It's slow" doesn't impress me; selecting from a system view doesn't > need to be lightning-fast. Well, how about "the code is going to be quite a lot less readable"? C can manipulate floats natively, but not numerics. Also, as was pointed out upthread, the underlying data in shared memory is almost certainly never going to be infinite-precision; so using numeric in the API seems to me to be more likely to convey a false impression of exactness than to do anything useful. > However, the main thing here is that we need to do *something* here... Agreed, this has got to be pushed forward. regards, tom lane