Question:  I'm getting the "ORA-07445: exception encountered: core dump" error message and I cannot understand the meaning of the core dump file.  How do you resolve the ORA-07445 error?  The trace file notes:

Exception signal: 11 (SIGSEGV), code: 1 (Address not mapped to object), addr: 0x0, PC: [0x1024ef000, opidsa()+480]
*** 2015-03-29 16:15:22.349
ksedmp: internal or fatal error
ORA-07445: exception encountered: core dump [opidsa()+480] [SIGSEGV] [Address not mapped to object] [0x000000000] [] []
Current SQL statement for this session:
Select /*+ CHOOSE */ object_name ObjectName, object_type ObjectType from user_objects where object_name = :OBJNAME order by 2
 

Answer:  The ORA-07445 is a very generic error, OS dependent, and almost always requires logging a service request (SR) with Oracle Technical support on MOSC. 

See Note 153788.1 titled "Troubleshoot an ORA-600 or ORA-7445 Error Using the Error Lookup Tool" to find the details for your error.

In general, an "exception" is an un-trapped error, such as dividing a number by zero.  The docs note:

Error: ORA-07445 exception encountered: core dump

Cause : An operating system exception occurred which should result in the creation of a core file. This is an internal error.

Action : Contact Oracle Customer Support.

Common precipitators of the ORA-07445 include:

• High volume user transactions
   
• Software bugs (i.e. Bug 4098853).  See note 342443.1 on MOSC.
   
• Too-small RAM regions (shared_pool_size, java pool, large_pool_size), and a too-small application memory stack (e.g. PL/SQL array too small)
   
• Too small undo and temp segments
   
• Program errors (addressing outside of RAM region), e.g. S0C4.
   
• Improper NLS parameter settings
   
• Hardware errors
   
• Oracle block corruption
  
  and a host of other related issues. 

Oracle DBA's use alert mechanisms to send an e-mail to the DBA when ORA-07445 errors occur, e-mailing the associated core dump file.  MOSC now offers an ORA-7445 search tool, as described in MOSC note Note:208922.1, and you can supply details from the Oracle trace file to see the exact cause. 

Other common causes of the ORA-07445 include:

• High-volume, high RAM usage can cause ORA-07445
   
• The shared pool is too small to hold the fixed structures
   
• Improper SCSI disk configuration

In sum, the ORA-07445 has a multitude of causes and contact with Oracle technical support is always required.