"Lex Spoon" <lex at cc.gatech.edu> is widely believed to have written:

> 
> Tim Rowledge <tim at sumeru.stanford.edu> wrote:
> > Another possibility is to make each message a file;
[snip]
> 
> This would be fine for the messages, but not for the *indexes*, I don't
> think.  I'm guessing, for example, that your mail program uses
> subdirectories to handle separate "folders" ?
Actually no, it doesn't. So far as I can work out (they don't supply the
source code - can you believe it?) the indices are monlithic but each
message lives in a separate file in a rather complex tree (related to
the demented old Acorn file system restriction of 77 files per
directory, now laid to rest) denoted purely by a number I suspect plays
the role of an ID.

How about:-
each index is stored in an eponymous file.
each message is stored in a separate file, named in some abstract manner
to make the indices as compact and easily parsable as possible.
subdirectories used at system's convenience to avoid excessively large
directories (Acorn can now handle 80,000 without much problem but
>200,00 is considered a bad move)

Just a thought.

tim
-- 
Tim Rowledge, tim at sumeru.stanford.edu, http://sumeru.stanford.edu/tim
Drugs may lead to nowhere, but at least it's the scenic route.