Proj4text is still working

[Paul Ramsey]

On Wed, Apr 24, 2024 at 6:46 AM José Carlos Martínez via postgis-users
<postgis-users at lists.osgeo.org> wrote:
> I am making some changes in proj4text of the spatial_ref_sys table, to apply a transformation between datums (+towgs84).

Don't make changes to existing, defined entries, make yourself a new entry.

> It appears that PostGIS is not using the values from proj4text, and instead is using the values from proj.db in the proj directory.

Yes, if it can dereference an SRID to an entry in proj.db, that entry
will be what is used. This allows richer and more correct transforms
than can be achieved with the proj string entries alone.

> I would like to ask if proj4text values still take priority (as in previous versions), with respect to proj.db?
> I mean, the first place PostGIS looks at the values to perform a coordinate transformation is still proj4text?

No, the first place is the proj.db. This is why if you want a custom
system you should make a new entry.

ATB,

P

>
> Thanks
>
> Jose Martinez
>
>