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From: dww@stl.UUCP (David Wright)
Newsgroups: net.arch
Subject: Re: RMS {SHORT}
Message-ID: <132@stl.UUCP>
Date: Thu, 21-Mar-85 13:47:28 EST
Article-I.D.: stl.132
Posted: Thu Mar 21 13:47:28 1985
Date-Received: Tue, 26-Mar-85 05:28:59 EST
References: <552@decwrl.UUCP>, <50@daisy.UUCP> <130@stl.UUCP>, <251@tilt.FUN>
Organization: STL,Harlow,UK.
Lines: 40

>>When I first started to use VMS I thought all that Index Sequential stuff was
>>way over the top - but now I'm wiser and actually use IS files I find they
>>are very effective - but still amazingly complex to fully define.  What I
>>find very impressive is that you DON'T NEED TO BOTHER about all the 
>>complexity - DEC have a special editor (EDIT/FDL) which designs the file
>>organisation for you - you answer its questions about how many records you'll
>>have/where and what the keys are/do you expect records to be entered in 
>>sequential order or not/etc.  and it does the rest - even tells you how good
>>it thinks the result will be.  It's the sort of programme which would be
>>called 'AI' if written in LISP but as it's probably in BLISS ...
>> 
>>Other file system developers please copy!
>
>Other file system developers please ignore.  There's no reason why you can't
>have IS/VSAM/* files but keep them out of the kernel.  Use a simple stream
>model and supply the routines and the above program as a user library and
>a user program.
>
>	Ray Chen
>	princeton!tilt!chenr

Yes yes please do keep the file system out of the kernel - why did you think
I wanted it in there?  Our own RT O/S work managed to keep it separate.  I was
referring in my original item to DEC VMS, where the file system is a (fairly)
separate entity called RMS.  Use of libraries for file operations are not
always the answer though - they are for compact systems, but not for biggies
like VMS.  One important advantage of having IS etc. built in to the operating
system (not into its kernel though) is that it encourages the language 
developers for that system to support the full set of facilities, including
(e.g.) IS access.  In VMS, IS access is almost as easy to use as sequential
for most languages, even in Pascal and DCL (DEC's appology for a shell), which
do not usually have such options without getting out the system library manual.

But what you seem to have missed entirely is WHAT I want other designers to
copy - which is that if you introduce a fundamentally complex thing like 
Index Sequential file structure, give the user tools to manipulate it without
his/her having to be an expert.

P.S. please don't lets argue about how RMS is too big and has far too much 
stuff in it; we all know that - especially all those file types!