Re: When should I worry?

Alexander Staubo wrote:
> ....
> For the monitoring, however, you can log your queries along with
> timings and timestamps, and copy them into a tool like R to
> statistically analyze your performance over time. You will be able to
> predict the point at which your system will be too slow to use, if
> indeed the performance degradation is expontential.
> ...


In my experience the more common situation is to "go off a cliff."
Everything hums along fine and the increases in table-size and user-base
have very little impact on your response times. Then suddenly you run
out of some resource (usually memory first).You hit swap and as your
few-millisecond query takes seconds or minutes your request queue backs
up, new connections are denied and everything goes downhill fast.

I think that keeping an eye on system resource trends via sar or similar
is more likely to provide the desired warnings of "sudden dropoff ahead".

Cheers,
Steve