Running clustering queries

[Regina Obe]

> "Regina Obe" <lr at pcorp.us> writes:
> 
> > Paul and Sandro,
> >
> > Any thoughts on this.  I know we went back and forth with "Why don't
> > we just populate spatial_ref_sys using postgis_srs_all or some other
> > such thing or why don't we just change spatial_ref_sys to a view that
> > relegates to reading these from proj.db make spatial_ref_sys a view or
> > why don't we make it a reduced set.
> > Not sure where we landed on that discussion.
> >
> > Before the issue was because we supported such old proj versions, but
now
> our minimum for 3.5 is 6.1 so all the options we had are now doable with
our
> minimum proj version.
> 
> I think part of this comes down to
> 
>   Are we just deferring to EPSG, or are we becoming an authority for
>   including and/or defining SRSes?
> 
> I thought it was "postgis uses database in proj and is not an authority",
but am
> I off?

Well we are definitely not an authority and would rather not be.
We tried to keep the spatial_ref_sys in sync with EPSG out of necessity, but
since 2.5, all that is needed is a proj.db and we relegate all processing to
proj.db metadata except where the record doesn't exist in proj.db.  The only
thing we rely on is the SRID, auth_srid and authority and when no authority,
we assume EPSG.

It is still convenient to have these in spatial_ref_sys but not a necessity
anymore and in fact I think users might prefer a spatial_ref_sys that has
just the spatial_ref_sys they need.
The search would be slightly faster, not to mention a lighter table.