Python Type 4 (drivers)

[Dave Brueck]

On Tue, 18 Feb 2003, Greg Brondo wrote:

> Rene Pijlman wrote:
> > Greg Brondo:
> >
> >>Has anyone looked at the possibility of creating a Type 4 (java)
> >>like drivers for python (completely python native code) ?
> >
> >
> > I assume you're talking about an implementations of the DB-API.
> > For any database in particular?
> >
> Yes.  But in python native code (no c extensions -- Just like Type 4
> drivers work in Java).  The initial driver would be for MySQL.  MY
> reasoning here is I'd trade some performance for even greater portability.

I looked into it for awhile for Oracle because I had many Linux boxes that
needed DB access from Python and I didn't want to install the monstruous
Oracle client on each box. In the end I just figured out the (much
smaller) subset of files needed and installed those instead, but I'm still
interested in the idea.

Before I got the Oracle client subset install working I also looked into
these approaches:

#1 - Using the pure-Java drivers from Jython - I actually used this one
for about a year and the DB part worked great but it was a nuisance to
make all my other modules work properly under Jython (lots of network
stuff so it often didn't work out-of-the-box in Jython).

#2 - Finding the Java source for the pure-Java drivers and porting them to
Python. Since the Java drivers are pretty lightweight it wouldn't be a
huge undertaking to port them to Python.

#3 - Decompiling the Java classes and then trying option #2. I couldn't
get them for Oracle of course, although decompiling the Java bytecode
revealed that it was less than 60k LOC in the semi-gibberish that
decompilers spit out. As hideous as it sounds, I ported about 20% of the
files as a proof of concept (in a weird way it was kind of fun). In the
end I dropped it though because I figured out the "small Oracle install"
thing, above, and without any source code comments that expressed the
intent of each bit of code it was really hard to create a good test suite
for the ported code. I didn't want to live with code that I couldn't have
much confidence in.

The pure Java interfaces run over TCP so if you could get the DB vendor to
publish the protocol they use then that would be a fairly easy task to
create a Python version. Barring that, the source code to the Java drivers
would work too.

-Dave