[postgis-users] Problem with ST_intersects

[James Sewell]

Hello All,

I think I have found a bug. For the data attached the following commands yield interesting results, with the output of ST_intersects seemingly changed by the where clause.

  plm25=> select  a.id, ST_intersects(a.the_geom, b.the_geom) from apoly as a, aright as b where a.id = 1954 or a.id =2034 order by id;
    id  | st_intersects
  ------+---------------
   1954 | f
   2034 | t
  (2 rows)

  plm25=> select  a.id, ST_intersects(a.the_geom, b.the_geom) from apoly as a, aright as b  where a.id = 1954 or a.id =2033 order by id;
    id  | st_intersects
  ------+---------------
   1954 | t
   2033 | t
  (2 rows)

Anyone have any ideas why this might be so?

----
James Sewell
Solutions Architect
Ardec International
Office: (03) 86803200
Mobile: 0414 688 892

________________________________________
From: James Sewell
Sent: Tuesday, 21 June 2011 11:51 AM
To: Mark Leslie
Subject: Shape files

Hello,

Attached are the two shape files; apoly has the point layer, aright is the large polygon I want to detect intersections with.

Also included is commands.txt which has the commands which cause the problem.

I have tested on the following and got the incorrect results:

   CentOS: POSTGIS="1.5.2" GEOS="3.1.1-CAPI-1.6.0" PROJ="Rel. 4.7.1, 23 September 2009 " LIBXML="2.6.26" USE_STATS

   Solaris: POSTGIS="1.5.2" GEOS="3.1.1-CAPI-1.6.0" PROJ="Rel. 4.7.1, 23 September 2009" LIBXML="2.6.31" USE_STATS


I will post it to the list as well this afternoon if you have no luck, let me know.

----
James Sewell
Solutions Architect
Ardec International
Office: (03) 86803200
Mobile: 0414 688 892

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