On Thu, Aug 17, 2006 at 03:09:30PM -0400, Alvaro Herrera wrote:
> stark wrote:
>
> > Actually I was already looking into a related issue and have some work here
> > that may help with this.
> >
> > I wanted to test the online index build and to do that I figured you needed to
> > have regression tests like the ones we have now except with multiple database
> > sessions. So I hacked psql to issue queries asynchronously and allow multiple
> > database connections. That way you can switch connections while a blocked or
> > slow transaction is still running and issue queries in other transactions.
> >
> > I thought it was a proof-of-concept kludge but actually it's worked out quite
> > well. There were a few conceptual gotchas but I think I have a reasonable
> > solution for each.
>
> I have had an idea for some time that is actually much simpler -- just
> launch several backends at once to do different things, and randomly
> send SIGSTOP and SIGCONT to each. If they keep doing whatever they are
> doing in infinite loops, and you leave it enough time, it's very likely
> that you'll get problems if the concurrent locking (or whatever) is not
> right.
This is probably worth doing as well, since it would simulate what an
IO-bound system would look like.
--
Jim C. Nasby, Sr. Engineering Consultant jnasby(at)pervasive(dot)com
Pervasive Software http://pervasive.com work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461