Re: root knowledge

Andrew Waugh <> Wed, 13 May 1992 02:18 UTC

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Subject: Re: root knowledge
In-Reply-To: Your message of "Tue, 12 May 92 10:58:50 -0400." <>
Date: Wed, 13 May 1992 11:16:43 +1000
From: Andrew Waugh <>

A couple of other points in your message that I'd like to discuss:

> I should point out that any number of database system vendors
> would be most happy to sell us products that could run circles
> around our X.500 implementations if all we wanted was high performance
> searching on a centralized -- in a single "DSA" -- database.

Yes, this is true now. But I wouldn't necessarily expect it to be true
for ever. One major reason why existing database systems outperform X.500
is the exceedingly general database model provided by X.500. For example,
attributes are identified by OIDs. OIDs are an indefinite sequence of
arbitrarily long numbers. This maps extremely poorly into the fixed field
design of conventional database designs. Conventional databases are a mature
technology; databases for X.500 are a VERY immature technology.

> X.500's
> strength is in the infrastructure it provides for distributing
> information, not in its ability to provide for implementations
> that have blindingly fast operations.]

X.500 has a couple of other strengths as well.

The first is its flexibility. It is easy (or it should be easy :-) to
define new types of attributes if your organisation has particular needs
that is not reflected in the standard. This is in contrast to many of the
existing telephony systems that I have seen.

The second is in its standardised interface. This allows the purchase or
development of specialised DUAs for particular applications. The DUA
used by a manager sitting at her desk will be quite different to the one
used by the telephonist sitting at his. Further, these DUAs can be brought
from different vendors. In the long term, the upgrading of DSAs and DUAs is
much easier.

These strengths are strong enough that at least a few Australian companies
are interested in X.500 even if the system they purchase is not distributed.

andrew waugh