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EXTPROC inconsistently errors

Question asked by sherriekubis on Feb 12, 2016

Oracle RDBMS 12.1.0.5

Oracle Enterprise Linux 6.6

SDE 10.2.2 Patch 290200

 

We have some feature classes with srid 2882, and I've found some with srid 300002.  I understand that the srid's should match to participate in an ST_ overlay function when EXTPROC kicks in.  However, these must be supported transformations because for the most part, it works, just slower.

 

However, there are times that this error returns instead of the in-place transformation happening:

ERROR:

ORA-28579: network error during callback from external procedure agent

ORA-06512: at "SDE.ST_GEOMETRY_SHAPELIB_PKG", line 100

ORA-06512: at "SDE.ST_RELATION_OPERATORS", line 340

 

It's quite inconsistent, where sometimes it works, sometimes it doesn't.  In troubleshooting other EXTPROC issues, I've created a nightly 'health check' programs, that does an ST_INTERSECT with feature classes that meet a certain criteria and another static multi polygon fc.  It runs at night, no errors found.  If I run the mixed srid interactively, it errors. 

 

I've been looking at this for a long time and tested may scenarios, but I'm stumped.  My answer going forward is to only overlay those fc's with matching srid's.  I'd like to understand what's going on here though. 

 

At one point we opened a ticket with ESRI support and the answer was that it's our data.  Yes, it was, and i now know it was because the srid's were different.  When two input geometries have different spatial references (different SRID values), the ST overlay operator transforms the shape geometry to the same spatial reference prior to performing the relational comparison.  This results in extra time spent in memory while the transformation happens, but it should still work and not error.  Sometimes it does, sometimes it doesn't. 

 

Any insights are appreciated.

 

Sherrie

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