[postgis-users] abs_next_left_edge and next_left_edge

[Sandro Santilli]

On Wed, Mar 19, 2014 at 11:53:33AM +0100, Rémi Cura wrote:
> Hey Dear List,
> 
> somebody knows exactly what is the difference bteween those 2 columns in
> postgis topology?

The "abs" one was just a facility to allow for
the field to be a valid foreign key into edge_id.
Not sure it's still needed with newer postgresql,
haven't tried. Would be something like:

  FOREIGN KEY ( abs(next_left_edge) )
  REFERENCES <toponame>.edge (edge_id);

Let me know if you find anything interesting
about that. Would save 2 "abs" fields per record
in the edge table...

--strk;