ORACLE环境遇到的ORA-600 [qkacon:FJswrwo]

近期，某用户的数据库环境遇到报错ORA-00600: internal error code, arguments: [qkacon:FJswrwo], [3]。对于ORA-00600报错，在MOS上查询与一个BUG描述较为符合。ORA-600 [qkacon:FJswrwo] Using CONNECT BY (Doc ID 1070636.1)。

文档中提到了打补丁或修改隐含参数的方式来处理；打补丁需要停业务，影响较大；

尝试了修改隐含参数的方式，此种不再报错，应用系统恢复正常。相关信息如下：

ORA-00600: internal error code, arguments: [qkacon:FJswrwo], [3], [], [], [], [], [], [], [], [], [], []
The partial call stack may contain:
kgeasnmierr qkacon qkaqkn qkadrv qkadrv opitca kksLoadChild kxsGetRuntimeLock kksfbc kkspsc0 kksParseCursor opiosq0 kpooprx kpoal8

CAUSE
Bug 9105678 CONNECT BY QUERY FAILED WITH ORA-600 [QKACON:FJSWRWO]
This occurs when running a query which has a connect-by view and contains() function in the outer query
blocks of the view.

SOLUTION
To implement solution please do the following:
1. Install Patch 9105678 if available for your platform and DB version
2. Use the workaround:
alter session set "_optimizer_connect_by_cost_based" = false;
3. This bug is fixed in 12.1.