Article on Predicate

[Jaroslaw Staniek]

On 8 January 2011 18:04, mutlu_inek <mutlu_inek at yahoo.de> wrote:
> Dear Commit-digest community and dear Jaroslaw,
>
> I proofread and corrected the Predicate article. Not every single quirk in its language has been fixed, but the article is quite readable now. There would be an advantage to reorganizing the article so that the argumentative structure is more intuitive, but that would take more work and I am not sure whether it would be welcome. I made tons of changes already. Regarding its language, I would say that it is nearly ready to go. There is one passage that remains unclear to me, however. I would be very happy, if someone could provide insights into what it is supposed to mean:
>

Thanks for your support, mutlu!
Below are corrections of my own mistakes; please let me know if
something is still unclear.

> Paragraph 9:
> "These are also built on top of KexiDB and that validated values of the abstraction layer in even for the client/server processing or even 3-tier architectures. During Kexi 1.1 times, Kexi offered a plugin > running its own web server..."

In the meantime Kexi Web Forms plugin have been developed as a Google
Summer of Code 2008 project. Like any other, also this plugin accesses
the database backend through the KexiDB abstraction. This development
validated usefulness of KexiDB in client/server applications and even
in 3-tier architectures. Web Forms was offered in Kexi 1.1 with its
own lighttpd-based web server.

>
> The remaining issue with this article is that I am not sure whether the history of the project it represented accurately. In the beginning, it is claimed that KexiDB 1 supported MySQL only,

I found some more info, so there's update:

In the beginning (2002) only MySQL and CQL++ [http://www.cql.com]
database backends were supported by Kexi. Only a few database access
features were abstracted (that would be called KexiDB version 0), and
much of the dependent code was in the Kexi code itself. The CQL++
backend (file-based) was then replaced in 2003 by SQLite what prompted
to the development of KexiDB abstraction layer version 1, from
scratch.

> Later on, however, it is mentioned that there was support for many more databases in KexiDB 1. I believe that the latter is correct, i.e. that KexiDB was the result of the need to support many DBs.

this is true but for KexiDB 2, please see below [1] for explanation

> and that the introduction of SQLite prompted its rewrite, which resulted (together with a porting to Qt4) in KexiDB 2.

this is not true, these were Qt 3 times; so rather "the introduction
of SQLite prompted its rewrite, which resulted in KexiDB 1."

> The support for all but MySQL and SQLite, however, was dropped with the port to Qt4 (i.e. with creating KexiDB 2) and this is still the case for Predicate. If this is indeed correct, I will fix the article accordingly.

I made a big mistake in my text. Below is the correction regarding drivers.

OLD text: "KexiDB for Kexi 1 offered support for xBase (dBase), Sybase (and MS
SQL Server) and Oracle backends. Support for these drivers in KexiDB 2
(Kexi 2) has been removed, and this is also the case for Predicate.
Maintainers for these are needed for Predicate."

NEW text: "KexiDB 1 supported MySQL, PostgreSQL, ODBC and SQLite 2 and
SQLite 3.
KexiDB 2 compared to version 1 initially increased number of supported
backends thanks to a number of active contributors.
Because of that, KexiDB 2 originally also supported xBase (dBase),
Sybase (and MS SQL Server) and Oracle backends.
[http://websvn.kde.org/trunk/koffice/kexi/kexidb/drivers/?pathrev=956576]
During the development KexiDB 2 and porting to Qt 4, however, support
for anything but MySQL, PostgreSQL, and SQLite 3 has been dropped;
also this is also the case for Predicate.
Maintainers for the disabled backends are needed for Predicate. The
old source code is possible for reuse."

I'd like to add something important regarding supporters:

"There were at least two companies supporting KexiDB development.
AutomatiX GmbH which hosts kexi-project.org also supported
improvements in 2003
[http://websvn.kde.org/?view=revision&revision=231391]. OpenOffice
Software LLC owns a lot of credits as it was the sponsor of the core
developer of KexiDB and Kexi, Jarosław Staniek, in 2003-2007
[http://openoffice.com.pl/en/]."

-- 
regards / pozdrawiam, Jaroslaw Staniek
 http://www.linkedin.com/in/jstaniek
 Kexi & Calligra (kexi-project.org, identi.ca/kexi, calligra-suite.org)
 KDE Software Development Platform on MS Windows (windows.kde.org)