>There is an interesting case study at MSDN regarding an n-tier design where the authors indicate that they would have replaced VB middle-tier components with VC++ ATL components due to latency problems (the amount of time it takes to load and or communicate with other objects).
>

One way to solve latency is to host the middle tier objects in MTS... you can specify how long an object will stay 'there' even after it's client is done with it, this saves the need of the time to instantiate the object.

>This got me to thinking....in a VFP shop, maybe what should be done is to design a virtual n-tier but physical 2-tier system: Create standalone VCX files or PRG's with class defs for data services and business rule enforcement and selectively link these file into projects and EXEs. So, you would pool the middle-tier into a ibrary, yet never compile them out as separate EXEs or DLLs.
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>Is anybody doing anything like that? Or is it really a bad idea? :-)

How is this different than traditional two tier?

1. You can scale the middle tier.

2. You can't limit SQL connections and give the middle tier access to say a pool of 5 connections.

BOb