ORA-07445 : exception encountered: core dump [%s] [%s]
ORA-07445 is a critical error generated by an oracle database when it has receives a fatal signal from the operating system. This error may be raised in either a foreground or background process. The most common reason for this error is where a pointer in memory is overwritten in error by a software problem. In this event, when the pointer is used to lookup the data it is pointing at, this may likely reference an area of memory without the process address space. Read more about the cause, interpretation and resolution of the error ORA-07445 error below
ORA-07445 : What can cause this error
Bug in Oracle Code
Change in reference libraries [ If you have recently applied OS patches, it may be wise to relink the binaries ]
Code changes in application that causes invalid/null value conditions where a valid value is expected
Software issues like incorrect Libaries due to invalid environment variables primarily related to PATH and LD_LIBRARY_PATH
ORA-07445 : Where is the diagnostic information
When an ORA-07445 occurs in an oracle database, the error is written to the database alertlog. Along with the error, a trace file is written to the background or user dump dest directory of oracle. Also a core dump may be created in the core dump destination directory.
ORA 7445 : Anatomy of the Error
There are two typical signals seen, i.e, SIGBUS (signal 10, bus error) and SIGSEGV (signal 11, segmentation violation).
Examples of the Error can be as follows :
ORA-7445: exception encountered: core dump [some_SQL()+268] [SIGBUS] [Invalid address alignment]   
ORA-7445: exception encountered: core dump      
Example 1 shows that the error occurred in some_SQL() and a SIGBUS signal was sent. Example 2 has very less information indicating a signal 10 was received but the function is not identified.
Oracle metalink provides detailed information on troubleshooting the errors. The Note 153788.1 - Troubleshoot an ORA-7445 Error
ORA 7445 : Resolution and working with Oracle Support
ORA 7445 error cannot just be eliminated by the oracle database administrator due to the complexity involved in resolving this error.
To reduce the amount of time taken by the Oracle Support team to reduce this error, dba should try to reproduce the situation and identify the SQL or Operation that can reproduce this error
Open an ITAR with Oracle using metalink and Create an RDA of the Oracle database and update the TAR with the alert log, trace files and the core dumps that the error has generated
Review the following notes provided by oracle to successfully resolving an ORA 7445 error. Documents and Links mentioned below will require that you have access to Oracle Metalink
Metalink Note 153788.1 : ORA 7445 Search Tool
Metalink Note 164968.1 : What is an ORA 7445 Error