[pgrouting-users] ERROR: Error computing path: | SQL state: 38001

[Stephen Woodbridge]

Palatla,

It is not clear what might be causing this problem. Normally when you 
get an error on the server there is an error message reported with the 
error text you got. I just looked at the code and I do not see anyway to 
generate the error without additional error message. So I'm guessing 
that maybe the server crashed. This could be because you have multiple 
copies of the libraries installed or some other system issues. For 
issues related to the data:

Do you actually have a column "reverse_cost" in the delhi_road table? Is 
it populated with not NULL values?

How big is this table?
select count(*) from delhi_road;

Typically we use a bbox query on the roads table to select only the 
roads needed for the solution. Unless this is a small table you should 
probably change this query to something like:

'SELECT id, source, target,x1,y1,x2,y2,cost,reverse_cost from delhi_road 
where 
st_expand(setsrid(makeline(makepoint(xstart,ystart),makepoint(xend,yend)),4326),0.001) 
&& the_geom'

Where xstart, ystart and xend, yend are the xy of the start and end of 
the route.

4326 is you SRID
0.001 is a small tolerance to expand the bbox by in the units of the 
geometry column. Pick a number like 500m or the equivalent in degrees.

-Steve

On 2/22/2012 3:40 AM, Palatla Srikanth wrote:
> Hi,
>
> We are developing an web application that users PostgreSQL 8.4 +
> PostGIS1.5  + Pgrouting 1.03 + development using (Java + Struts + Hibernate)
>
> *When this Query is executed:*
>
> SELECT ST_AsText(the_geom),id AS Coords FROM delhi_road WHERE id IN
> (SELECT edge_id FROM shortest_path_astar('SELECT id, source,
> target,x1,y1,x2,y2,cost,reverse_cost from delhi_road',550,662,true,true))
>
> We are getting the below mentioned error and the other users accessing
> the application were too facing the database exceptions. Can someone
> help us to fix this issue.
>
> -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> *Error from the postgreSQL query*
>
> ERROR:  Error computing path:
>
> ********** Error **********
>
> ERROR: Error computing path:
>
> SQL state: 38001
>
> ------------------------------------------------------------------------
>
> *Query used:*
>
> **
>
> SELECT ST_AsText(the_geom),id AS Coords FROM delhi_road WHERE id IN
> (SELECT edge_id FROM shortest_path_astar('SELECT id, source,
> target,x1,y1,x2,y2,cost,reverse_cost from delhi_road',550,662,true,true))
>
> -------------------------------------------------------------------------
>
> *Error on the Application server (IDE)*
>
> [ INFO] 46:48 ( MapServiceDAO.java:generateRoute:1525 )
>
> Query is......SELECT ST_AsText(the_geom),id AS Coords FROM delhi_road
> WHERE id IN (SELECT edge_id FROM shortest_path_astar('SELECT id, source,
> target,x1,y1,x2,y2,cost,reverse_cost from delhi_road',550,662,true,true))
>
> [ INFO] 46:48 ( MapServiceDAO.java:generateRoute:1552 )
>
> Exception aala.........org.postgresql.util.PSQLException : ERROR: Error
> computing path: _
>
> Feb 22, 2012 11:46:48 AM org.apache.catalina.core.StandardWrapperValve
> invoke
>
> SEVERE: Servlet.service() for servlet GenerateRoute threw exception
>
> org.hibernate.SessionException : Session was already closed
>
>        at org.hibernate.impl.SessionImpl.close( SessionImpl.java:303 )
>
>        at com.tis.hib.util.HibernateSessionFactory.closeSession(
> HibernateSessionFactory.java:86 )
>
>        at com.tis.dao.impl.MapServiceDAO.generateRoute(
> MapServiceDAO.java:1572 )
>
>        at com.tis.servlet.GenerateRoute.doGet( GenerateRoute.java:125 )
>
>        at javax.servlet.http.HttpServlet.service( HttpServlet.java:690 )
>
>        at javax.servlet.http.HttpServlet.service( HttpServlet.java:803 )
>
>        at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(
> ApplicationFilterChain.java:290 )
>
>        at org.apache.catalina.core.ApplicationFilterChain.doFilter(
> ApplicationFilterChain.java:206 )
>
>        at org.apache.catalina.core.StandardWrapperValve.invoke(
> StandardWrapperValve.java:230 )
>
>        at org.apache.catalina.core.StandardContextValve.invoke(
> StandardContextValve.java:175 )
>
>        at org.apache.catalina.core.StandardHostValve.invoke(
> StandardHostValve.java:128 )
>
>        at org.apache.catalina.valves.ErrorReportValve.invoke(
> ErrorReportValve.java:104 )
>
>        at org.apache.catalina.core.StandardEngineValve.invoke(
> StandardEngineValve.java:109 )
>
>        at org.apache.catalina.connector.CoyoteAdapter.service(
> CoyoteAdapter.java:261 )
>
>        at org.apache.coyote.http11.Http11Processor.process(
> Http11Processor.java:844 )
>
>        at
> org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(
> Http11Protocol.java:581 )
>
>        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(
> JIoEndpoint.java:447 )
>
>        at java.lang.Thread.run( Thread.java:619 )
>
>
> *Regards,*
> *Palatla Srikanth*
>
>
> _______________________________________________
> Pgrouting-users mailing list
> Pgrouting-users at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/pgrouting-users