On 07.01.2013 20:51, Pavel Bortnovskiy wrote:



This is more of a general question. Our application uses Derby in the in-memory mode only.

When the application is configured to use complex queries, such configuration causes CPU utilization (on the Linux server) to go as high as 300% or even higher. Using simpler queries don’t seem to lead to such high utilization. Is there any way to control or lower CPU utilization by Derby?

Hi Pavel,

I don't believe there is such a mechanism in place, at least not specifically for the in-memory back end.

Since this is in-memory, the latency associated with page operations is very low. Do you know if Derby is using the CPU for something useful (i.e. processing queries effectively), or is the CPU spent on wasteful activities?
One potential wasteful activity is moving data back and forth from the page cache (page cache too small?).
Is this a highly concurrent scenario?



Thank you,

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