🧩 ORA-07445: Exception Access Violation

 🧩 Introduction

ORA-07445 is a critical Oracle error indicating that the database process has encountered a low-level exception, such as an access violation or segmentation fault. This error often terminates the session or even the database process, and is accompanied by trace files detailing the cause. Understanding ORA-07445 is essential for DBAs to maintain database stability.

Error Message Example:

ORA-07445: exception encountered: core dump [sigsegv] [addr:0x000000] [pc:0xabcdef]

Common Causes

Oracle software bugs.

Corruption in memory structures (SGA, PGA).

Problematic SQL execution or indexing operations.

Incompatibility with certain OS patches or libraries.

Data corruption in critical tables or indexes.

Step 1: Check Alert Logs and Trace Files

Locate the alert log and associated trace files in:

$ORACLE_BASE/diag/rdbms/<db_name>/<SID>/trace

Trace files include the error type, stack trace, and process ID (PID). This information is crucial for diagnosis.

Step 2: Identify the Module and Operation

Trace files often specify which Oracle module triggered the error, e.g., kghf or lgwr. Also note the SQL or DML operation being executed at the time.

Step 3: Search Oracle Support

Use the ORA-07445 lookup tool to find known bugs:

https://support.oracle.com/epmos/faces/DocumentDisplay?id=406319.1

Enter the exception type and Oracle version to identify patches or workarounds.

Step 4: Apply Fixes or Workarounds

Apply recommended Oracle patches if a known bug is identified.

Avoid or modify SQL statements triggering the error.

Rebuild corrupted indexes or affected objects.

Consider increasing memory parameters if the error relates to SGA or PGA.

Step 5: Contact Oracle Support

For unknown or severe ORA-07445 errors, create a Service Request. Include:

Trace files

Alert logs

SQL executed at the time

Oracle version and patch level

Conclusion

ORA-07445 errors signal serious internal exceptions but are typically resolvable with trace analysis, proper patching, and guidance from Oracle Support. Monitoring your database and keeping software up-to-date helps reduce recurrence.