[postgis-devel] PostGIS 2.5 what should be minimum requirements?

[Regina Obe]

While we are still in infancy of PostGIS 2.5 (and probably at least a year
away from release), I'd like to get requirements out of the way and propose
the following:

1) Drop support for PostgreSQL 9.4 and 9.5  (so PostgreSQL 9.6 - PostgreSQL
11 will be supported)
9.4 has the main annoyance of not supporting true KNN and I'm tired of
explaining this to folks and having people with pg_upgrading from these
lowers being screwed when upgrading because they can no longer do

ALTER EXTENSION ...  cause they are already at 2.5.0

9.5 doesn't support Parallelism and I suspect we may need to do some
restructuring for some aggs in 2.5, I'd just assume not have to make special
concessions for folks trying to pg_upgrade from a PostgreSQL 9.5 2.5
extension to 9.6+

2) Make GEOS 3.5+ the minimum (for 2.4  GEOS 3.4 was the minimum)  - we've
got too much stuff that requires 3.5 already that is turned off for lower
and newer GEOS has some robustness improvements. 

3) Make Proj 4.9+ the minimum currently our minimum is proj 4.7 I think.  As
discussed it's on the table to redo some of the geography stuff like
ST_Segmentize using proj 4.9+ features.


Anyone have issues with the above?  

PSC folks, if you are okay with all the above please give a +1

If you are okay with some and not others, I can break apart so we can at
least decide on some pieces.


Thanks,
Regina