Re: Patent issues and 8.1

Neil Conway wrote:

> IMHO, the patent issue is *not* a "potential problem" for a lot of people,
> it *is* a problem -- it makes people uncomfortable to be deploying
> software that they know might cause them legal headaches down the line. It
> also makes life difficult for people distributing commercial versions of
> PostgreSQL.

I live in Europe, and right now, the patent, if granted, would not have any
effect on me. Even if Europe will have patents on software, I doubt that
this ARC algorithm will be patentable in Europe.

> I've posted a patch to -patches that replaces ARC with LRU. The patch is
> stable -- I'll post some code cleanup for it tomorrow, but I've yet to
> find any bugs despite a fair bit of testing. The patch also reverts the
> code to being quite close to 7.4, which is another reason to have some
> confidence in its correctness.
>
> I think the best solution is to replace ARC with LRU in 8.0.1 or 8.0.2,
> and develop a better replacement policy during the 8.1 development cycle.

I have not much confidence in such changes in a minor release, seeing that
there is really not much more testing on them than regression testing (am I
wrong?) an perhaps simple benchmarking in this case. I believe many really
annoying or dangerous bugs have only been found in field testing.

Don't get me wrong, Neil, I trust your coding skills. But replacing ARC with
LRU seems a rather big change, which could introduce new bugs and have
performance issues. And the change also effects bgwriter behaviour.

Please don't rush out untested core components, and perhaps think about the
people who are quite comfortable with ARC (e.g. us guys in Europe over
here).

If ARC replacement can be done in a 8.0.* release, it doesn't have to be now
in a rush, does it?

Best Regards,
Michael Paesold