What I want to count is the number of plans that have been considered cheapest_path. Since if a path is considered to be a cheapest_path, the postgres optimizer need to spent time on comparison. I think this is what I want.
2009/10/4 Martijn van Oosterhout <klep...@svana.org> > On Sat, Oct 03, 2009 at 04:20:59PM +1000, ????????? wrote: > > Since I also need to consider gego, is this the best way to do it? > > I think you need to be clearer about what you're trying to count. > Consider a nestjoin plan where: > > - For the inner side it considers 7 paths and throws away 4. > - For the outer side it considers 6 paths and throws away 2. > > Do you want the number 3*4=12 or 7*6=42? Or something in between (what > if in addition to a nestjoin plan otther possibilities are possible). > > As you can see, you can't talk about complete plans because they don't > exist until right at the end, until then it's just considering how to > combine different paths in sensible ways. > > Have a nice day, > -- > Martijn van Oosterhout <klep...@svana.org> http://svana.org/kleptog/ > > Please line up in a tree and maintain the heap invariant while > > boarding. Thank you for flying nlogn airlines. > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.9 (GNU/Linux) > > iD8DBQFKyIiaIB7bNG8LQkwRAklcAJsFBOQE/xAscZm0ok4WwxVh+C6x8ACfYuNz > G4GpDdQ4IuTXGWc5QHhD5dc= > =ynTH > -----END PGP SIGNATURE----- > >
