svanderclock wrote:

> hello,
>
> i notice that the first time a run some particular select, it's can take something like 5 to 10 seconds (i also see the hardrive working) and if i redo the same select just after the first execute the response is imediate (< 10 ms). if i just change something in the select (replace where xxx=2 by where xxx=1 for exemple) it's take again 5 to 10 seconds for the first execute and the next execute gave imediate result.
>

Without knowing a lot more about your database (table sizes,
indexes, index selectivity) and the exact nature of your query,
the plans it generates, and server parameters like cache size,
there's no way to say what the problem is.

> how to improve this ? is it a cache probleme ?

Not exactly. The cache is the reason that the second and
subsequent iterations are fast.


Good luck,

Ann