On Thu, Dec 10, 2015 at 4:55 AM, Andreas Seltenreich <seltenre...@gmx.de> wrote:
> Tom Lane writes:
>> Merlin Moncure <mmonc...@gmail.com> writes:
>>> Aside from the functional issues, could your changes result in
>>> performance regressions?
> [...]
>> It's a little bit harder to gauge the impact on planner speed.  The
>> transitive closure calculation could be expensive in a query with many
>> lateral references, but that doesn't seem likely to be common; and anyway
>> we'll buy back some of that cost due to simpler tests later.  I'm
>> optimistic that we'll come out ahead in HEAD/9.5 after the removal
>> of LateralJoinInfo setup.  It might be roughly a wash in the back
>> branches.
> On the empirical side: I see a speedup of 0.4% in testing speed with the
> patch applied.  It could very well be me venting the room one additional
> time during the second session, resulting in the CPUs spending more time
> in their opportunistic frequency range or something.

Really...wow.  That satisfies me.   You ought to be commended for
sqlsmith -- great stuff.


Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:

Reply via email to