[fpc-devel] TClientDataset (was: Dnamic packages support)

[Michael Van Canneyt]

On Sat, 3 Nov 2007, Joost van der Sluis wrote:

> Op zaterdag 03-11-2007 om 19:57 uur [tijdzone +0100], schreef Michael
> Van Canneyt:
> > 
> > Packages and the missing TClientDataset are the only 2 remaining
> > things 
> > stopping me from using FPC/Lazarus for my daytime job. All else is 
> > covered or can be covered with a minimal amount of work. 
> 
> You'll have to explain the TClientDataset to me. Do you need a
> symantical identical equivalent of TClientDataset?

I need all features offered by TClientDataset:

- 3-tier database handling, TProvider and all.
- Local filtering
- Local sorting/indexing
- Locate()
- Maintained Aggregates
- Load/Save to file (briefcase model)

And all features are critical; We have about 3200 instances in 1 application,
almost all of them using all of the features mentioned, maybe with exception
of the aggregates.

> Or do you only miss some features in sqldb?

SQLDB will be good for our server tier, so I can drop the IBX.
But it's not suitable for the client layer.

As I see it, TClientDataset should be built on top of TBufDataset.
Local filtering is available as fas as I know (or did you put it 
in TSQLQuery ?), and the indexing probably also can somehow be 
managed. The locate can be done with a filter. The maintained
aggregates would need to be implemented from scratch, as well
as the packet handling and file handling...

Michael.