[postgis-devel] Much slower processing on GEOS 3.9.0 versus 3.8.0 for geodesic area calculation - Upgrade to PROJ 7.2.1 causes issue

[Raúl Marín]

On 15/5/21 1:58, Paul Ramsey wrote:

 > The fix is a little invasive, I'm "so so" on backporting it into the 
stable branches. Interested in comments regarding that.

Adding fcinfo everywhere was a pain, so it's only fair that removing it 
would be too. I'm not against backporting it, but I'm not sure the gain 
justifies the risk and effort.

I like those tricks to get Postgis schema without the fcinfo. If I 
recall correctly somebody (mobilitydb?) had some issues related to it 
because they were calling Postgis from C without passing the fcinfo. 
This change should avoid that, I think.

 > It works cleanly for me locally and evades the start-up cost of proj. 
I haven't done anything to make the cache access any faster yet, but 
it's a low priority since most people only have a handful of projections 
in their cache anyways.

The cache can hold up to 128 transformations, which should be enough for 
most cases, and has some basic intelligence to remove the least used 
objects when it's full but it might need to be improved if being full 
ends up being the norm. It's really simple so I don't expect any 
performance issue coming from that unless the cache size is increased.


Regards,
Raúl.