On Thursday, September 20, 2012 05:37:42 PM Tom Lane wrote: > Heikki Linnakangas <hlinnakan...@vmware.com> writes: > > I've been slowly continuing to work that I started last winder to make > > XLogInsert scale better. I have tried quite a few different approaches > > since then, and have settled on the attached. This is similar but not > > exactly the same as what I did in the patches I posted earlier. Sounds pretty cool from a quick read.
> This sounds pretty good. I'm a bit bothered by the fact that you've > settled on 7 parallel-insertion slots after testing on an 8-core > machine. I suspect that it's not a coincidence that you're seeing > a sweet spot for #slots ~= #CPUs. If that is what's happening, we're > going to want to be able to configure the #slots at postmaster start. > Not sure how we'd go about it exactly - is there any reasonably portable > way to find out how many CPUs the machine has? Or do we have to use a > GUC for that? Several platforms support sysconf(_SC_NPROCESSORS_CONF) although after a quick look it doesn't seem to be standardized. A guc initialized to that or falling back to 4 or so? Andres -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
