Re: [RFC][PATCH]: CRC32 is limiting at COPY/CTAS/INSERT ... SELECT + speeding it up

The Saturday 30 October 2010 11:05:17, Andres Freund wrote :
> Hi,
>
> This thread died after me not implementing a new version and some potential
> license problems.
>
> I still think its worthwile (and I used it in production for some time) so
> I would like to implement a version fit for the next commitfest.
>
> The code where I started out from is under the zlib license - which is to
> my knowledge compatible with PGs licence. Whats the position of HACKERS
> there? There already is some separately licenced code around and were
> already linking to zlib licenced code...
>
> For simplicitly I asked Mark Adler (the original Copyright Owner) if he
> would be willing to relicence - he is not.
>
> For anybody not hording all old mail like me here is a link to the archives
> about my old patch:
>
> http://archives.postgresql.org/message-
> id/201005202227(dot)49990(dot)andres(at)anarazel(dot)de
>
>
> Andres

I forgot to report this a few months ago:

I had a very intensive COPY load, and this patch helped. The context was a
server that was CPU bound on loading data (8 COPY on the same table in
parallel, not indexed). This patch gave me a 10% boost in load time. I don't
have the figures right now, but I could try to do this test again if this can
help. At that time, I just tried it out of curiosity, but the load time was
sufficient without it, so I didn't spend more time on it.