Hi Daniel,

Just had a read of your thread. We're using Qt and Firebird... on
Windows and Mac (Linux in the future), writing in C++. Everything is
working nicely... we've come from a Delphi background (also using
Firebird, with dbExpress) and are porting a reasonably large app across
(100k+ lines).

What you describe sounds very interesting. Our app uses Firebird
constantly while running, but the amount of data in our tables is quite
small, so while we're aware of the issues you've raised, we've not had
the need to deal with them as yet.

Regards,

Peter Lee

Daniel Albuschat wrote:

> Hello Firebird users and developers,
>
> I'm currently working on a library providing asynchronous and
> thread-safe database access to the Firebird database.
>
> I've seen so many applications that display data from a database in a
> grid-like fashion that just don't do it right. There are a magnitudes
> of problems with it. Just to mention a few:
> - Some load only the first few datasets and loading the complete
> result set blocks the application and may take extremely long.
> - Others automatically load datasets when scrolling in the grid, but
> the user does still not know how many datasets exist in the result
> set.
> - The worst implementation loads all datasets when displaying the grid
> and hence they can take minutes to open a specific dialog.
> - None I have seen so far give an indication of how many datasets
> exist in the result set (i.e. by sizing the scroll-bar appropriately).
> Even database-managers that should be very sophisticated in this task,
> often fail in this regard.
>
> Asynchronous access means that you can tell Firebird to start
> executing and fetching datasets and they'll be provided to your
> application via a signal or message as soon as the dataset arrives. In
> the meantime, your application can continue processing user-input or
> some other tasks. I'm doing this by creating one worker-thread per
> database-connection that receives and processes tasks from other
> threads. This is a huge improvement over traditional, blocking means
> of fetching datasets.
> It's especially useful for server and GUI applications, as the main
> program flow is never interrupted (for too long) and data processing
> happens asynchronously.
>
> The library includes a Grid-widget that can be connected to a buffer
> and is filled with data "in the background", without ever interrupting
> the user experience. It already works remarkably well and extremely
> fast (I still have some optimizations to do, like adding a
> Small-Object-Allocator to optimize storage for fetched fields) on
> arbitrary table-sizes.
> A single database-connection (and hence a single thread) can serve
> multiple "receivers" at the same time. Of course, with a linear
> slowdown.
> You can use it for un-threaded web- or application-servers, too.
>
> I'm using C++ with Qt to develop this library. Qt is an awesome
> toolkit of very high quality and made the whole thread-synchronisation
> and scheduling - which usually is a huge hassle - a non-issue.
> However, it's theoretically possible to write bindings to about any
> language and toolkit that's out there.
>
> So I am interested in:
>
> a) How many Firebird-users are developing using Qt (either C++ or Jambi)?
> b) What other languages and toolkits are popular among Firebird-users?
>
> I'd be greatful for anyone reporting the tools he's working with.
>
> Kind regards,
>
> Daniel Albuschat
>
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>
>
>
>
>

--
Peter Lee ptle@...
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