Re: Looking for keyed file package

[kilgallen@eisner.decus.org (Larry Kilgallen)]

In article <7seobv$7ib$1@nnrp1.deja.com>, Robert Dewar <robert_dewar@my-deja.com> writes:

> One thing to be aware of here is that a naive implementation of
> indexed files may well be slower than using a database built on
> top of a sophisticated indexed file system.

I think the original poster said the project had a 4 week useful
lifespan, so it seems me Implementation Time would dominate.

> It is quite surprising what can be done with good indexed
> file systems. For example, the Realia COBOL compiler uses a
> sophisticated form of leading/trailing key compression which
> results in an average stored key length of about 16 bits,
> regardless of the actual physical key length.

The VMS implementation of RMS does key compression and data compression
as well, but I think that all started back when disk and memory space
were much more dear.  I/O bandwidth one area of computer performance
that does not seem to be advancing so much as the others, so these
days typical advice might be to engage in extensive caching of the
index data if performance is important.

Larry Kilgallen