This content has been marked as final. Show 2 replies
Hi unnamed user 810260,
Oracle Spatial defines a valid outer ring as counter-clockwise, no ifs ands or buts about it. Getting your rings into this orientation is your responsibility either by not accepting backwards polygons or by running SDO_UTIL.RECTIFY_GEOMETRY (or SDO_MIGRATE.TO_CURRENT) on each polygon you bring into Oracle Spatial.
A reference might be similar issues surrounding importing WKT into Oracle Spatial
SDO_UTIL.FROM_WKTGEOMETRY seems ignorant of ring rotation
The OGC spec for WKT does not specify a ring rotation so your average WKT polygon could have rings going either way. As Dr. Ravada responds in that thread, it our problem to fix it. The generic WKT utility for Oracle Spatial just loads whatever its given however the rings are rotated and does not attempt to fix anything.
So a best practice might be to rectify everything. I am not really a big fan of rectify myself (search the list for folks talking about NULL output). Rather I just test the ring rotation and reverse it if I find the problem.
Thanks for your time & response, it really helped me to proceed further.