mory used by application sometimes limited by interpreter (for example in PHP it is possible to specify limit
in <code>php.ini</code> file). 

<LI>If you specify very large pool size, leaving no free memory for other applications and operating system, 
then swapping will cause significant performance degradation.

<LI>Operating system itself maintains file buffers (it is not possible in Java to avoid it).
So data is cached twice. Certainly accessing data from page pool is much faster than from 
operating sy