Thanks. I am doing data testing to check out traversibility of submitted network data.
To assess the extent of correctness of line to line connections. I will ask our DBA team to see whether the memory allocation error can be resolved. I will try out generate start node and endnote from lines present and try out traversibility testing. Regards,. David On Sunday, 8 May 2022, Imre Samu <[email protected]> wrote: > > 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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