After upgrade of one database to 12c, the customer complained, that one application (which uses Spatial & Graph) isn’t working properly. After analysing & tracing it, I found the root cause of it – SDO_GEOM.sdo_convexhull.
In some cases, this function crashes the whole application raising ORA-03113:
ORA-03113: end-of-file on communication channel Process ID: 22675 Session ID: 1900 Serial number: 63606
I found this error message in the alert log:
Exception [type: SIGSEGV, Address not mapped to object] [ADDR:0x0] [PC:0x5487EC5, mdcgcvxhl()+4677] [flags: 0x0, count: 1] Errors in file /u01/app/oracle/diag/rdbms/gispro/GISPRO/trace/GISPRO_ora_22675.trc (incident=640395): ORA-07445: exception encountered: core dump [mdcgcvxhl()+4677] [SIGSEGV] [ADDR:0x0] [PC:0x5487EC5] [Address not mapped to object]  Incident details in: /u01/app/oracle/diag/rdbms/gispro/GISPRO/incident/incdir_640395/GISPRO_ora_22675_i640395.trc
I couldn’t find anything related to this error message, so I opened a service request to Oracle Support. And the guys were really fast!! After only a couple of days, I got confirmation that this issue is a bug (BUG 22886582 – EXCEPTION IN SDO_GEOM.SDO_CONVEXHULL) and also the workaround for it!!
alter session set events '54677 trace name context forever, level 8192';
They provided me also the possibility to request a backport for our version.
Thank you guys from Oracle Support!