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Re: knoppix-med: cant get past login screen



On Tue, 12 Nov 2002 08:25, Andrew Ho wrote:
>   Notify and listen are not standard SQL (e.g. SQL92). Therefore, I think
> it is a terrible idea to use it - if you care about using GnuMed with a
> different database backend.

We can't use a different database backend anyway, sinc we heavily depend on 
stored procedures for all sorts of triggers, which is not portable.

Notify and listen is an absolutely *essential* feature for a complex database 
accessed and modified by many users simultaneously. How else would a client 
get to know that the record he is displaying right now just has been modified 
by another client?

Think of a "waiting room" widget on the doctor's interface. The receptionist 
pops a patient who has just arrived onto the "waiting list" table, and now 
the doctor's screen has to reflect it. How would you do it without 
notify/listen? Poll in regular intervals? That would generate a huge 
unneccessary backend traffic and would make programming the client a lot more 
complicated, since there are virtually *hundreds* of tables where such 
asynchronous backend communication is needed.

That said, there was another main reason why PyPgSQL was chosen as "the" 
adapter: ease of installation. Especially our typically less knowledgeable 
Windows user is usually  unable to install anything that doesn't come in a 
"setup.exe" version.

Horst
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