[pgrouting-users] Using pgr_nodeNetwork on a selection

Marc-Andre_Goderre · April 17, 2015, 11:47am

Can I use pgr_nodeNetwork on only a part of a table or a selection.

I started the pgr_nodeNetwork on a table and the process failled because of memory problem. Half of the rows have been processed and the mytable_noded has the data of all data processed. I want to continu the process only on the row that doesn’t been processed.

something like

SELECT pgr_nodeNetwork(‘(select w.* from way w join way_noded wn on w.id <> wn.old_id)r’, 5,‘id’, ‘line2d’);

Thanks

Marc

Vicky_Vergara1 · April 17, 2015, 1:04pm

Right now its not possible, but when I used it (long time ago) I did something like the following:
First of all I after doing an analysis to the the graph, I grabbed the edges that where in conflict and placed them in a different table. That was less than 1% of the total edges. That new table is the one I applied pgr_nodeNetwork, after the nodding was done I carefully reinserted the results (following the example in the documentation and adjusting the idea to my needs) into the original table and re-created the topology.
But as for the moment, pgr_createTopology, for the particular section, will erase ALL topology and only create the topology of that section, So pgr_creteTopology has to be called with the whole table, work is in progress so that create topology in a section will keep any topology already in the table.

I added as a request feature to allow nodding only in particular sections of the table.

Vicky

From: magoderre@cgq.qc.ca
To: pgrouting-users@lists.osgeo.org
Date: Fri, 17 Apr 2015 11:47:35 +0000
Subject: [pgrouting-users] Using pgr_nodeNetwork on a selection