How about this:
I'ts very easy with Midas to do your own ApplyUpdates in the server via a
custom method. From the client, instead of calling ApplyUpdates you call
RemoteServer.AppServer.SaveMyData(clientDataset.Delta, ClientId). In the
server you can save the deltas to a cache directory thus:
cds.Data := IncomingDelta;
cds.SaveToFile(directory + ClientID + datetime);
Then notify the clients that there is new data using sockets or udp or even
a timer. From the client scan the cache directory for new files not from
the current client and apply them in sequence to you local copy.
----- Original Message -----
From: Donovan J. Edye <[EMAIL PROTECTED]>
To: Multiple recipients of list delphi <[EMAIL PROTECTED]>
Sent: Friday, January 28, 2000 7:27 PM
Subject: [DUG]: MIDAS - Here we go again....
> G'Day,
>
> Sorry if this seems like it is back again, but I just want to pose some
more
> questions after taking all the suggestions etc. I received on board and
> having done some actual playing instead of just having theoretical reading
> knowledge.
>
> Assumptions:
>
> * Using MIDAS
> * 3 Tier Model (Presentation, Application, Back End)
> * One "Master" Database on Back End Tier
> * Bunch of local database copies (One copy per client)
> * Clients on presentation layer can either be updaters (can update the
> "Master") or subscribers (They want their local copy of the data updated
> when there is a change to the "Master") (Potentially Updates could also be
> subscribers)
>
> I know we have gone over this, but I still have some questions:
>
> I need to achieve 3 things here:
>
> 1. Have multiple updaters all update a "Master" database
>
> I can see how MIDAS could do this. No problem here. This could also be
done
> with Midware, but then I would have to roll my own equivalent of
> TDataSetProvider (In particular) and could get away with the MWTable
> TDataSet descendent that comes with MidWare but TClientDataSet would be
> better.
>
> 2. Have any changes made to the "Master" database via the application
server
> come back to all the clients in some form so that their local databases
can
> be updated
>
> Could this be done in some way with MIDAS?? Perhaps have application
servers
> on the clients that were called from the "Master" application server to
> apply updates to the local database copies. The other option would be to
do
> this with some connection protocol that passes the relevant SQL statements
> as strings from the Application Layer to the Clients. This would be easy
to
> achieve with MidWare
>
> 3. Have all subscribers (read only) use their LOCAL data for queries
>
> This is obviously done using local BDE.
>
> From the 3 issues above I see that:
>
> 1. Is made easy and robust with MIDAS OR Tricker & possibly less robust
with
> MidWare.
> 2. Is still tricky. Would have to be done without MIDAS.
> 3. Is simple BDE
>
> Suggestions, corrections etc.??
>
> ------------------------------------------------------------------------
> --Donovan
> Donovan J. Edye [www.edye.wattle.id.au]
> Namadgi Systems, Delphi Developer
> Web: www.namsys.com.au E-Mail: [EMAIL PROTECTED]
> Voice: +61 2 6285-3460 Fax: +61 2 6285-3459
> TVisualBasic = Class(None);
> ------------------------------------------------------------------------
>
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> Website: http://www.delphi.org.nz
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