Continuing on clustering queries

[Regina Obe]

> [... deleting for the sake of brevity ...]
> 
> >> This SQL variant does not return errors, but it isn't visible in my
> >> QGIS
> > project
> >> (it's an ongoing project with about twenty layers built with PostGIS).
> >>
> >> Any advice?
> >>
> >> Should I direct this inquiry to the QGIS list?
> >>
> >> Thank you,
> >>
> >> Max
> > It might be because it returns a geometry collection.  I recall QGIS
> > not liking geometry collections.
> > Also depending on how you are creating this -- is this a view or an
> > inline SQL, you might need to force the type for it to show as a layer
option.
> 
> Regina: In these subsequent queries you are specifying SRS 4326; shouldn't
it
> be 2163, the SRS of all of the other layers?
> 
> 

No.  In subsequent queries, I used ST_Transform(geom,2163) only in the
clustering to get a good cluster number and so we could use meters for our
distance clustering.  So 2163 was just used for input to ST_ClusterDBScan
which returns a number.

The geometry itself should still be in it's original 4326 srid unless you
changed it. 4326 is still preferable for most visualization tools is
preferable.