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Re: User concurrency thresholding: where do I look?

From: "Jignesh K(dot) Shah" <J(dot)K(dot)Shah(at)Sun(dot)COM>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Josh Berkus <josh(at)agliodbs(dot)com>, pgsql-performance(at)postgresql(dot)org, Alvaro Herrera <alvherre(at)commandprompt(dot)com>
Subject: Re: User concurrency thresholding: where do I look?
Date: 2007-07-20 18:56:31
Message-ID: 46A1055F.9010304@sun.com (view raw or flat)
Thread:
Lists: pgsql-performance
Yes I did see increase in context switches and CPU migrations at that 
point using mpstat.

Regards,
Jignesh


Tom Lane wrote:
> "Jignesh K. Shah" <J(dot)K(dot)Shah(at)Sun(dot)COM> writes:
>   
>> There are no hard failures reported anywhere. Log min durations does 
>> show that queries are now slowing down and taking longer.
>> OS is not swapping and also eliminated IO  by putting the whole database 
>> on /tmp
>>     
>
> Hmm.  Do you see any evidence of a context swap storm (ie, a drastic
> increase in the context swaps/second reading reported by vmstat)?
>
> 			regards, tom lane
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
>        choose an index scan if your joining column's datatypes do not
>        match
>   

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Next:From: Tom LaneDate: 2007-07-20 19:13:13
Subject: Re: User concurrency thresholding: where do I look?
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Subject: Re: [PERFORM] 8.2 -> 8.3 performance numbers

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