Further memory question [was: Clear the computer's memory?]

[R Kimber]

I have a further question about memory use. As I write, having been
forced to reboot about 10 hours ago, and having 4 not very
demanding apps open, plus the background stuff that is started at boot,
Gkrellm tells me that I have 1702MB of memory free out of 2GB.

However, I know from experience that, without further action by me,
this figure will drop to about 700 MB some time within the next 24
hours.

I'd like to know what it is that does this.  The only thought I have is
that it relates to slocate and represents the database being held in
memory.  Could it be that? If so, is there a way of telling it not to
keep it in memory?  I use locate relatively rarely.

If it's not this, what is it?  I haven't worked it out from 'top' - is
there another utility I might use?

- Richard.
-- 
Richard Kimber
http://www.psr.keele.ac.uk/