| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Greg Stark <gsstark(at)mit(dot)edu> |
| Cc: | Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>, Manfred Koizar <mkoi-pg(at)aon(dot)at>, Mark Cave-Ayland <m(dot)cave-ayland(at)webbased(dot)co(dot)uk>, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: Cost of XLogInsert CRC calculations |
| Date: | 2005-05-18 05:12:26 |
| Message-ID: | 17441.1116393146@sss.pgh.pa.us |
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| Lists: | pgsql-hackers |
Greg Stark <gsstark(at)mit(dot)edu> writes:
> Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
>> Do we know that? The results I showed put at least one fundamentally
>> 32bit platform (the PowerBook I'm typing this on) at dead par for 32bit
>> and 64bit CRCs.
> Wait, par for 32-bit CRCs? Or for 64-bit CRCs calculated using 32-bit ints?
Right, the latter. We haven't actually tried to measure the cost of
plain 32bit CRCs... although I seem to recall that when we originally
decided to use 64bit, someone put up some benchmarks purporting to
show that there wasn't much difference.
regards, tom lane
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