I love this argument because I can see both sides...
I have always used bound controls in VB and Delphi. With Delphi we use
Midas because it works and it saved many man many hours creating our own
version of something that we felt Borland/Inprise new how to do better than
we did. In the end, it probably has cost about the same. Another
advantage is that there are many developers using Midas and most problems
are solved before we encounter them.
We use 2 third party libraries (SPIS TCompress and Async Pro). Everthing
else we created ourself because we couldn't but it or we found free source
to do what we wanted.
Sure, Inprise could go broke or Midas may be radically altered but what we
have works now and there is no reason to dump it just cause there is a
cooler tool or new version. Most of our code is still Delphi 3.
Also, with any design, the OS may change (as it frequently does these days)
and code will probably break. No software is an island...
As for scalability, having a ui control data-aware does not effect
scalability, it's what you do with it that matters. For example, grids are
normally very dangerous with traditional C/S 2 tier apps. With Midas, you
have complete control over what get's into the grid and how updates are
dispatched to the server. The only thing you can't control is the midas
data packets structure over the wire - but you can easily control when and
how much is transmitted. I haven't seen anything else that does this as
well.
Eliot Muir <[EMAIL PROTECTED]> on 22/04/99 00:22:47
Please respond to [EMAIL PROTECTED]
To: Multiple recipients of list delphi <[EMAIL PROTECTED]>
cc: (bcc: Peter Jones/Logistics&Information
Technology/Christchurch/Foodstuffs)
Subject: Re: [DUG]: How thin the client will be?
Call me a conservative....but why bother with all these
proprietary networking stuff? Bound data
type controls are renowned for making unscalable applications - the
little bit of time saved in throwing apps together is usually absorbed in
the
maintenance and slow performance that these complicated technologies
result in - especially when they don't work.
DCOM and CORBA etc. don't achieve what they are supposed to - which is
transparent operation of applications over networks. I haven't used MIDAS
to
be
honest but I bet it's not the magic panacea that the spec sheet describes.
The best approach is also the simplest. Implement your own simple
client-server library
based on on straight TCP/IP or maybe RPC, stream over some type of hash
table
object with a
version numbering scheme, and get your server to decipher the calls and
talk to
the
database.
The advantages are that it's transparent - you know exactly when and what
data
is being
sent across the network. It's easy to debug, you have complete control so
it's
easy to optimise
- you don't have to spend heaps of time evaluating crap third party
products
which don't work.
And lastly no license fees or danger of your client-server architecture
becoming obsolete if
the product you used gets dumped or the company which makes it goes under.
Yanbo Li wrote:
> Thanks Nic, dbOverNet licence sounds much cheaper than Midia.
> I will contact with them.
> I've already developed a Midas prototype. But the licence is too
> expensive, we have to get rid of it.
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]] On Behalf Of Nic Wise
> Sent: Wednesday, April 21, 1999 9:23 AM
> To: Multiple recipients of list delphi
> Subject: Re: [DUG]: How thin the client will be?
>
> have you thought about using dbOverNet?
> www.dbovernet.com - same idea as MIDAS (which, IMO, is your best option,
> tho it IS expensive), but I'm guessing their cost structure is a little
> different :)
> N
> Yanbo Li wrote:
> >
> > Thanks, Your information is very helpful.
> >
> > Cheers
> > Yanbo
> >
> > -----Original Message-----
> > From:
> [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED]] On Behalf
> Of
> > [EMAIL PROTECTED]
> > Sent: Tuesday, April 20, 1999
> 2:14 PM
> > To: Multiple recipients of
> list delphi
> > Subject: RE: [DUG]: How
> thin the client will be?
> >
> > IB Objects and FIB components
> rep[lace the BDE for
> > Interbase but you still
> > need the IB Client.
> >
> > DCOM is not necessarily
> Windows only... but if you can
> > find anyone who nows
> > how to get DCOM for Mac or
> DCOM or Solaris working then
> > you are doing well.
> > It's hard enough to get it
> going on NT!
> >
> > You could use JBuilder and
> Corba for the server end
> > too...
> >
> > Peter Harrison IT
> <[EMAIL PROTECTED]> on 20/04/99
> > 14:45:54
> >
> > Please respond to
> [EMAIL PROTECTED]
> >
> > To: Multiple recipients of
> list delphi
> > <[EMAIL PROTECTED]>
> > cc: (bcc: Peter
> Jones/Logistics&Information
> >
> Technology/Christchurch/Foodstuffs)
> > Subject: RE: [DUG]: How
> thin the client will be?
> >
> > Using standard Delphi the
> TQuery requires the BDE to be
> > installed, along
> > with the database client of
> choice. You don't mention
> > the database
> > type, so lets assume we are
> talking Interbase. You will
> > need to install
> > the Interbase Client on the
> client machines, the BDE,
> > and your
> > application.
> >
> > This is not 'thin' client in
> the least.
> >
> > If you want to use Interbase
> you havn't got much choice
> > about any of
> > this, except that you might go
> with a product which
> > replaces the BDE
> > with a driver specifically for
> Interbase eliminating the
> > need for the
> > BDE (do these exist?)
> >
> > If you want to go with File
> Based Databases, such as
> > dBASE, you can
> > probably eliminate the
> database client and bde, and have
> > a single app,
> > and perhaps a DLL or two.
> 'Apollo' is an example
> > product for this
> > approach.
> >
> > Besides the n tier stuff there
> isn't much alternative.
> > You could always
> > start writing DCOM interfaces
> - conceivable by really
> > ugly - and Windows
> > dependant.
> >
> > Good luck...
> >
> > -----Original Message-----
> > From: Yanbo Li
> [mailto:[EMAIL PROTECTED]]
> > Sent: Tuesday, April 20, 1999
> 1:10 PM
> > To: Multiple recipients of
> list delphi
> > Subject: [DUG]: How thin
> the client will be?
> >
> > Many thanks in advance.
> > I need to know how thin the
> application will be if I
> > only use TQuery
> > and TDatabase to connect to
> remote server. If the app is
> > still very fat,
> > I have to manage to write my
> own driver which I am not
> > found of. Please
> > do not suggest me to use
> TClientDataSet and 3tier
> > technology.
> >
> >
> ------------------------------------------------------------------------
> > ---
> > New Zealand Delphi Users
> group - Delphi List -
> > [EMAIL PROTECTED]
> > Website:
> http://www.delphi.org.nz
> >
> >
> ------------------------------------------------------------------------
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> group - Delphi List -
> > [EMAIL PROTECTED]
> > Website:
> http://www.delphi.org.nz
> >
> >
> ------------------------------------------------------------------------
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> List - [EMAIL PROTECTED]
> > Website:
> http://www.delphi.org.nz
>
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> Website: http://www.delphi.org.nz
>
>
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