From: Pavel Stehule [mailto:pavel.steh...@gmail.com] > the cumulated lock statistics maybe doesn't help with debugging - but it > is very good indicator of database (in production usage) health.
I think it will help both. But I don't think the sampling won't be as helpful as the precise lock statistics accumulation, because the sampling doesn't give us exactly how effective our improvements to PostgreSQL code are. I remember PG developers used LOCK_STATS to see how many (or ratio of) lwlock waits decreased by applying patches. We can use the cumulated lock stats like: 1. SELECT * FROM pg_session_waits; 2. Run a benchmark. 3. SELECT * FROM pg_session_waits; 4. Calculate the difference between 1 and 3. Or, reset the wait stats before the benchmark run and just use the stats as-is. I'd like to know why you thought the cumulated wait stats isn't helpful for debugging. Regards Takayuki Tsunakawa
