Upgrade From 9i To 10g Caused Ora-0600 [Qctcte1], 
(Doc ID 417645.1)
Last updated on OCTOBER 02, 2019
Applies to:Oracle Database - Standard Edition - Version 10.2.0.2 and later
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Backup Service - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Cloud Service - Version N/A and later
Information in this document applies to any platform.
Query with "CONNECT BY" and "OUTER JOIN" failed with
ORA-00600: internal error code, arguments: [qctcte1], , , , , , 
For example :
Upgraded to 10.2.0.3.0 still error out and tried setting: _OPTIMIZER_COST_BASED_TRANSFORMATION=OFF still same error.
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