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Babyl files, slow as molasses
Date: Mon, 9 Nov 87 10:45 EST
From: J. Scott Penberthy <JSP@ibm.com>
Date: Fri, 6 Nov 87 21:29 EST
From: Barry Margolin <barmar@Think.COM>
Most mail file formats require the mail reading application to read
through message N to find the beginning of message N+1, because it must
search for the message delimiter.
Why not invent a *new* format, similar to the "KBIN approach," that
precompiles all this information? If one insists on treating mail files
like magnetic tapes, one is bound to lose.
Symbolics DID invent a new format, called KBIN. The original mail
referred to Zmail reading Babyl-format mail files. I presumed that he
is using Babyl format because he needs to be able to read his mail file
on other than Lispms. Another new format doesn't help unless all the
mail systems are taught to understand it. As long as Symbolics is
constrained to storing mail in text files in the server's native format,
it can't treat it as much more than a magnetic tape (it's actually less,
since you can back up a magtape).
Instead of using direct-access files, one could use a "directory"
approach, whereby each message is stored in a separate file. TCP-FTP
would support this.
This is, in fact, what the Berkeley Unix MH (aka Rand) mail system does
(as far as I know, there is no Symbolics support for this format). It
is somewhat wasteful of disk space due to file blocking. It is a
space/speed tradeoff that some might be willing to make, though.