> I am thinking of generating startnode and endnode values by using St_startpoint(geom) and ST_endpoint(geom), > Is this feasible?
if your input data is “noded” correctly - then YES ... “noded” network = at every intersection in your road/water network all the edges will be broken into separate road/water segments. And you have to assign the same "node id" for the same physical points. ( ST_DWithin magic ) be careful: The "Network Walking" example was a nodded network ( without an intersection! ) maybe you can test the https://postgis.net/docs/CreateTopology.html function also; Imre Shaozhong SHI <[email protected]> ezt írta (időpont: 2022. máj. 8., V, 3:38): > Testing shows that using startnode and endnode of id values of a line does > lead to a fast completion of processing. > However, at the moment, I am not sure whether these startnode (id values) > and endnode (id values) are correct. > > I am thinking of generating startnode and endnode values by using > St_startpoint(geom) and ST_endpoint(geom), > > And then try out your alternative method for recursive query to see > whether walk the network works. > > Is this feasible? > > Regards, > > David > > On Sun, 8 May 2022 at 00:59, Imre Samu <[email protected]> wrote: > >> Hi David, >> > There is a loop of recursive query. It runs at a point where it stops. >> >Can anyone provide pointers how to solve this problem or work around? >> >> Please share "this" recursive query; >> >> My guess: Probably you have a "forever/endless loop" in your data; *so >> you have to LIMIT the recursive part ;* >> >> related links : >> 1.) with limiting "depth" ( where depth < 1000 ) >> "Prevent infinite loop in recursive query in Postgresql" >> >> https://stackoverflow.com/questions/51025607/prevent-infinite-loop-in-recursive-query-in-postgresql >> 2.) with LIMITING clause >> https://www.cybertec-postgresql.com/en/recursive-queries-postgresql/ >> *"This example also demonstrates how an endless loop can be avoided with >> a LIMIT clause on the parent query."* >> >> Regards, >> Imre >> >> Shaozhong SHI <[email protected]> ezt írta (időpont: 2022. máj. 7., >> Szo, 15:23): >> >>> There is a loop of recursive query. It runs at a point where it stops. >>> >>> This error turned up.- ERROR: invalid memory alloc request size >>> 1073741824 >>> >>> Can anyone provide pointers how to solve this problem or work around? >>> >>> Regards, >>> >>> David >>> _______________________________________________ >>> postgis-users mailing list >>> [email protected] >>> https://lists.osgeo.org/mailman/listinfo/postgis-users >>> >> _______________________________________________ >> postgis-users mailing list >> [email protected] >> https://lists.osgeo.org/mailman/listinfo/postgis-users >> > _______________________________________________ > postgis-users mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/postgis-users >
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