Horton

Re: Cost of XLogInsert CRC calculations

Bruce Momjian <pgman@candle.pha.pa.us>

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From: Bruce Momjian <pgman@candle.pha.pa.us>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Greg Stark <gsstark@mit.edu>, Manfred Koizar <mkoi-pg@aon.at>, Mark Cave-Ayland <m.cave-ayland@webbased.co.uk>, pgsql-hackers@postgresql.org
Date: 2005-05-18T05:24:15Z
Lists: pgsql-hackers 
Tom Lane wrote:
> Greg Stark <gsstark@mit.edu> writes:
> > Tom Lane <tgl@sss.pgh.pa.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.

OK, thanks. I didn't know that.

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