[Qgis-developer] Perfs: a lot of WKB conversions

[Martin Dobias]

Hi Patrick

On Tue, Jul 19, 2016 at 11:30 AM, Patrick Valsecchi
<patrick.valsecchi at camptocamp.com> wrote:
>
> So yes, my per function numbers are not very accurate, but they are a very
> good indication of where time is spent. But, I still have the global numbers
> with a RELEASE build to see if changes are improving things.

Cool. By the way, there is also a cmake build type "release with debug
info" which should bring the best of the both worlds.


> The provider, at least PostGIS on the same machine, is not contributing too
> much on the time spent to do a simple GetMap, from what I've seen. But yes,
> when optimizing, you have to choose a scenario and it impacts a lot what you
> see.

If I remember correctly, the PostGIS provider actually spends quite
significant amount of time waiting for the response from server - the
wait is however not showing up in callgrind as the process is sleeping
during that time. PostGIS is also a case where parallel map rendering
helps a lot (when using multiple layers) as the waiting time is
reduced significantly.

Cheers
Martin