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: Manfred Koizar <mkoi-pg@aon.at>, Mark Cave-Ayland <m.cave-ayland@webbased.co.uk>, pgsql-hackers@postgresql.org
Date: 2005-05-18T03:51:52Z
Lists: pgsql-hackers 
Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > I don't understand why we are testing 64-bit CRC when I thought we
> > agreed that 32-bit was good enough for our purposes.
> 
> Well, we need to understand exactly what is going on here.  I'd not
> like to think that we dropped back from 64 to 32 bit because of one
> possibly-minor optimization bug in one compiler on one platform.
> Even if that compiler+platform is 90% of the market.

But isn't it obvious that almost any problem that CRC64 is going to
catch, CRC32 is going to catch, and we know CRC32 has to be faster than
CRC64?

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