Creating spatial indexes on geography slower than on geometry?

[Paul Ramsey]

Basically, yes. Calculating a bbox on a plane is just some min/max calls. Doing it on a sphere involves a lot of trig and huge functions. Calculating boxes is step one of index building. The geocentric geography index involves a varsize key, while the 2d geometry index uses a fixed size key. Even things like distance cost a lot more

https://docs.google.com/presentation/d/1G7UkT9szpyRcWPp59aVRfN1-f1jfuf40dwxs034M2RA/edit#slide=id.g4c694067b3_0_79

p


> On Nov 1, 2024, at 8:13 AM, thiemo at gelassene-pferde.biz wrote:
> 
> Is that because geometry is calculated in the plane whereas geography on a curved surface?
> 
> Paul Ramsey <pramsey at cleverelephant.ca> escribió:
> 
>> Yes, building a geography index is a lot more computationally expensive.
> 
> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20241101/82115895/attachment.htm>