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From Stanley Bradbury <Stan.Bradb...@gmail.com>
Subject Re: derby slow down
Date Tue, 06 Mar 2007 23:48:04 GMT
Nurullah Akkaya wrote:
>
> i have a select statement that takes around 100 - 200 msecs to 
> complete but after some writing to the table i pause writer threads 
> and  same select statement takes forever to complete ( 10 secs to 170 
> secs ) after restarting the application statement goes back to normal 
> speed. 
>
> any one else experiencing this behavior?            
>
>
>
>
I can only speculate but it could be that the distribution of the data 
in the tables have changed to the point where the cached plans for the 
queries are no longer optimal.  See the Tuning guide about plans going 
stale and what can be done.   Restarting the application will, of 
course, generate a new plan based on the current distribution and 
perform well again.



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