>>> On Wed, Oct 17, 2007 at 2:49 AM, in message
<00e001c81092$4b5aca50$2300a8c0@ssuruieda>, "ssurui"
<ssurui@mailst.xjtu.edu.cn> wrote:=20
=20
> After long time, the free memory is
> not increased, it still 300M memory vanished
=20
I think the one thing everyone knows as a fact is that the memory did
not vanish. Your latest message gives us a clue that what interests
you is why free (unused, idle, not giving you any benefit) memory
went down. If that is the question, it is because PostgreSQL goes
through the OS file systems, so RAM which is serving no other purpose
will automatically be used to cache data. If you need memory for
something else, the cache will be reduced to compensate.
=20
-Kevin
=20