I'm sorry, I can't let this go ...
> Date: Mon, 4 Aug 2003 09:35:39 +0100
> From: "Matthew J. Dovey" <[log in to unmask]>
> Unlike Z39.50 SRW is not necessarily tied down to a simultaneous
> user model where a connected user may be consuming resources without
> actually doing anything. SRW works on a simultaneous request
> model. Given that the number of active users don't all issue a query
> simultaneously, the number of active users can be much larger that
> the number of active requests - i.e. SRW can support implementations
> that are more efficient than the connection based ones.
Or to say the same thing a different way --
Unlike SRW Z39.50 is not necessarily tied down to a
simultaneous user model where a user needs to
re-connect every time he wants to actually do
anything. Z39.50 works on a persistent connection
model. Given that a typical user issues many queries
in a single session, the total number of requests that
can be handled can be much larger than the numnber
TCP/IP connections that have to be forged -
i.e. Z39.50 can support implementations that are more
efficient than the non-connection based ones.
To say that a connectionless model is "more efficient" than a
connection-based one is like saying that quadrupeds are "more
efficient" than bipeds -- it depends entirely on what you're trying to
do. (And since the overhead of keeping a TCP/IP connection open is
close to zero anyway, I think that in the great majority of scenarios
a connection-based approach is likely to be superior.)
/o ) \/ Mike Taylor <[log in to unmask]> http://www.miketaylor.org.uk
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