Re: AW: Re: TODO list

Zeugswetter Andreas SB <ZeugswetterA(at)wien(dot)spardat(dot)at> writes:
> Has anybody done performance and reliability tests with CRC64 ?
> I think it must be a CPU eater. It looks a lot more complex than a CRC32.

On my box (PA-RISC) the inner loop is about 14 cycles/byte, vs. about
7 cycles/byte for CRC32. On almost any machine, either one will be
negligible in comparison to the cost of disk I/O.

> Since we need to guard a maximum of 32k bytes for pg pages I would -
> if at all - consider to use a 32bit adler instead of a CRC, since that
> is a lot cheaper to calculate.

You are several months too late to re-open that argument. It's done and
it's not changing for 7.1.

regards, tom lane