Re: Npsql is much faster than ODBC ?

Alvaro Herrera wrote:

>Rainer Bauer wrote:
>> "Andrej Ricnik-Bay" wrote:
>>
>> >On Nov 7, 2007 2:40 PM, Rainer Bauer <usenet(at)munnin(dot)com> wrote:
>> >
>> >> That's nice to hear. But I respect licences as they are and the ODBCng driver
>> >> is licenced under the GPL.
>> >That doesn't mean that you're not allowed to use it with commercial
>> >applications; it just means that you need to be happy to provide the
>> >source for it on request.
>>
>> Which is exactly the reason why the LGPL licence was created. So that any
>> software can link against a library without the restrictions of the GPL.
>
>Keep in mind, though, that the ODBC driver is not linked to your app.
>It is only loaded on demand at run time, and can be replaced by any
>other ODBC driver. So AFAIU your application is "shielded" from GPL.
>IANAL of course.

Neither am I.

However, the GPL FAQ has an entry specially for this case:
<http://www.gnu.org/licenses/gpl-faq.html#NFUseGPLPlugins>

"If the program dynamically links plug-ins, and they make function calls to
each other and share data structures, we believe they form a single program,
which must be treated as an extension of both the main program and the
plug-ins. In order to use the GPL-covered plug-ins, the main program must be
released under the GPL or a GPL-compatible free software license, and that the
terms of the GPL must be followed when the main program is distributed for use
with these plug-ins."

The way I read this section is that linking to a GPL ODBC driver would imply
that I have to release my program under a GPL (compatible) licence.

This was one of the reasons why I added Postgres support to my program instead
of MySQL [1]. They altered the licence for their drivers from LGPL to GPL so
that you have to purchase a commercial licence.

Rainer

[1] In the meantime I am of course glad that I made this decision. I have not
only learned a lot more about databases, but especially that Postgres is
superior to MySQL ;-)