Re: [HACKERS] parallelizing subplan execution (was: explain and PARAM_EXEC)

2010-02-21 Thread Greg Stark
On Sun, Feb 21, 2010 at 3:25 AM, Robert Haas wrote: > What kinds of things would be > sensible to hand off in this way?  Well, you'd want to find nodes that > are not likely to be repeatedly re-executed with different parameters, > like subplans or inner-indexscans, because otherwise you'll get >

Re: [HACKERS] parallelizing subplan execution

2010-02-21 Thread Dimitri Fontaine
Robert Haas writes: > Probably. For one thing, you can't use fork(), because it won't work > on Windows. [...] > query. IOW, we're going to need, well, a connection pool in core. > *ducks, runs for cover* Well, in fact, you're slowly getting to the interesting^W crazy part of it. Now that you

Re: [HACKERS] parallelizing subplan execution

2010-02-20 Thread Mark Kirkwood
Robert Haas wrote: It seems to me that you need to start by thinking about what kinds of queries could be usefully parallelized. What I think you're proposing here, modulo large amounts of hand-waving, is that we should basically find a branch of the query tree, cut it off, and make that branc