Hi, I just stumbled upon this page
http://varnish.projects.linpro.no/wiki/ArchitectNotes where the author writes that caching of disk files within the application hurts performance on current operating systems. Right now, the data is in memory at least twice: the OS cache and the Derby cache which sounds suboptimal. And it gets worse if the OS decides to swap out the application's cache. With the widespread use of 64-bit machines and therefore a huge address space, is it possible to (optionally) disable the page cache and use memory mapped files instead? This would also solve the "how much page cache to use?"-problem. Sure on 32 bit you are limited to a database size of 1-3 GB but you should still see the speedup, especially on low memory systems. -- Kurt GnuPG 1024D/99DD9468 64B1 0C5B 82BC E16E 8940 EB6D 4C32 F908 99DD 9468
