One of the developers was performing a delete using a nested subquery, which was throwing out ORA-00600 errors. The ORA-00600 Lookup Tool on MOS suggested it was caused by this bug:
The workaround in the bug suggested running this ALTER SESSION command.
alter session set "_optimizer_unnest_disjunctive_subq"= FALSE;
Rather than alter the whole session, we used the OPT_PARAM hint, making the subquery look something like this.
(SELECT /*+ OPT_PARAM('_optimizer_unnest_disjunctive_subq' 'FALSE') */ ... FROM ...)
Slap in a comment reminding us to remove the hint when we move to 11.2.0.4 or 12c and job’s a good’un! 🙂
Cheers
Tim…