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

On Tue, Oct 27, 2015 at 2:33 PM, Jeff Janes <jeff(dot)janes(at)gmail(dot)com> wrote:
> 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:

this smells like thp compaction: