On Tue, Jan 28, 2014 at 7:41 AM, Marti Raudsepp <ma...@juffo.org> wrote:
> On Mon, Jan 27, 2014 at 9:26 PM, Alexander Korotkov > <aekorot...@gmail.com> wrote: > > For now, I have attempt to fix extra columns in mergejoin problem. It > would > > be nice if you test it. > > Yes, it solves the test cases I was trying with, thanks. > > > 1) With enable_partialsort = off all mergejoin logic should behave as > > without partial sort patch. > > 2) With partial sort patch get_cheapest_fractional_path_for_pathkeys > > function is much more expensive to execute. With enable_partialsort = > off it > > should be as cheap as without partial sort patch. > > When it comes to planning time, I really don't think you should > bother. The planner enable_* settings are meant for troubleshooting, > debugging and learning about the planner. You should not expect people > to disable them in a production setting. It's not worth complicating > the code for that rare case. > > This is stated in the documentation > (http://www.postgresql.org/docs/current/static/runtime-config-query.html) > and repeatedly on the mailing lists. > > But some benchmarks of planning performance are certainly warranted. > I didn't test it, but I worry that overhead might be high. If it's true then it could be like constraint_exclusion option which id off by default because of planning overhead. ------ With best regards, Alexander Korotkov.
