Linux command
pg_test_timing 命令
文本
复制后可按需替换文件名、目录或参数。
常用示例
Test timing overhead
pg_test_timing
Test for a specific
pg_test_timing -d [seconds]
Display version
pg_test_timing -V
说明
pg_test_timing is a tool to measure the timing overhead on your system and confirm that the system time never moves backwards. It repeatedly calls the system clock timing function and reports the average overhead per call, plus a histogram of call durations. Systems that are slow to collect timing data can give less accurate EXPLAIN ANALYZE results. Good results show most (>90%) individual timing calls taking less than one microsecond, with average per-loop overhead below 100 nanoseconds. Low overhead enables track_io_timing without significant performance impact.
参数
- -d _duration_, --duration=_duration_
- Specifies the test duration in seconds. Longer durations give slightly better accuracy and are more likely to discover problems with the system clock moving backwards. Default is 3 seconds.
- -V, --version
- Print the pg_test_timing version and exit.
- -?, --help
- Show help about pg_test_timing command line arguments and exit.
FAQ
What is the pg_test_timing command used for?
pg_test_timing is a tool to measure the timing overhead on your system and confirm that the system time never moves backwards. It repeatedly calls the system clock timing function and reports the average overhead per call, plus a histogram of call durations. Systems that are slow to collect timing data can give less accurate EXPLAIN ANALYZE results. Good results show most (>90%) individual timing calls taking less than one microsecond, with average per-loop overhead below 100 nanoseconds. Low overhead enables track_io_timing without significant performance impact.
How do I run a basic pg_test_timing example?
Run `pg_test_timing` in a terminal, then adjust file names, paths, flags, or remote targets for your system.
What does -d _duration_, --duration=_duration_ do in pg_test_timing?
Specifies the test duration in seconds. Longer durations give slightly better accuracy and are more likely to discover problems with the system clock moving backwards. Default is 3 seconds.