ORA-07445: core dump [qcdlgcd()+70] for Union All Statement : No More Data To Read From Socket (Doc ID 2028777.1)
Last updated on APRIL 13, 2017
Oracle Database - Enterprise Edition - Version 188.8.131.52 to 184.108.40.206 [Release 12.1] Oracle Database - Enterprise Edition - Version 10.2.0.4 to 10.2.0.4 [Release 10.2] Information in this document applies to any platform.
Select with UNION ALL fails with error
no more data to read from socket
The alert.log reports for the same:
ORA-07445: exception encountered: core dump [qcdlgcd()+70] [SIGSEGV] [ADDR:0x4] [PC:0xCDFF456] [Address not mapped to object] 
The call stack from the trace file includes functions like: