Re: [GENERAL] 回复: postgres cpu 100% need help

On Mon, Oct 26, 2015 at 8:30 PM, 657985552(at)qq(dot)com <657985552(at)qq(dot)com> wrote:

> Dear sir:
> Recently a wired question about postgresql database really
> bothered me a lot, so i really need your help. Here is the problem, in the
> most situations the postgre database work very well, Average 3500tps/s
> per day, the cpu usage of its process is 3%~10% and every query can be
> responsed in less than 20ms, but sometimes the cpu usages of its process
> can suddenly grow up to 90%+ , at that time a simple query can cost
> 2000+ms. ps: My postgresql version is 9.3.5 and the database is oltp
> server.
>

From all the lseeks on the same file, it looks like you are doing a
sequential scan on a table for the inside of a nested loop. What is the
query it is running, and what is the execution plan for it? To get that,
run:

explain (analyze, buffers) select o_count from ....

Cheers,

Jeff