[pgrouting-users] How to populate already existing "road_noded_vertices_pgr" table?

[Daniel Kastl]

On Mon, Aug 25, 2014 at 11:00 AM, Vladimir <fl_v at inbox.ru> wrote:

> Hi All
>
> I have a road network with appending a new segments sometimes.
>
> Then I copy the new segments into my "road_noded" table and execute
> -------------------
> SELECT pgr_createTopology('roads_noded', 0.1, 'geom', 'id',rows_where:='id
> > a last id')
> ------------------
> for affecting on the new segments only. But this action recreates my
> "road_noded_vertices_pgr" table completely for the new segments instead of
> appending the new vertices and referencing them to the new segments.
>
> 1) Is pgr_createTopology only for create not for update? Somebody knows
> other method or some trick?
>
Yes, this function does not do updates.
If you add or modify roads later, and if you don't want to keep old node
ID's, then you can't use this function.


> 2) Could I use native Postgis functions (ST_StartPoint,ST_EndPoint etc) in
> the event if no possibility?
>
I don't understand what you mean with "event", but yes, you can use any
PostGIS function to handle the updates. You could for example a trigger
function.

Daniel


-- 
Georepublic UG & Georepublic Japan
eMail: daniel.kastl at georepublic.de
Web: http://georepublic.info
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