From the objective of OSS-DB Exam Gold
- Troubleshooting - Troubleshooting common failures
Sample Question
4.02
Select the one accurate explanation for the following server log.
LOG: server process (PID 21334) was terminated by signal 11: Segmentation fault
DETAIL: Failed process was running: SELECT user_func();
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The query was canceled due to a user request.
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The pg_cancel_backend function was executed against the process.
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The pg_terminate_backend function was executed against the process.
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A SIGKILL signal was sent by the OOM Killer.
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A SIGSEGV signal was raised by the user_func user-defined function.
※This sample exam is different from those that appear in the actual OSS-DB Exam.
2025/06/02
Answer and Explanation
[Options A, B, C, and D]
For options A, B, C, and D, the server logs would show the following messages, indicating they are not accurate:
A,B
ERROR: canceling statement due to user request
STATEMENT: SELECT user_func();
C
FATAL: terminating connection due to administrator command
STATEMENT: SELECT user_func(); C
D
LOG: server process (PID 21334) was terminated by signal 9: Killed
DETAIL: Failed process was running: SELECT user_func();
[Option E]
A signal 11 (SIGSEGV) is logged when a segmentation fault occurs due to an incorrect memory access, often caused by a user-defined function.
In PostgreSQL version 9.2 or later, the log output also includes the statement the process was executing.
Therefore, option E is accurate.
The correct answer is E.