PGEO driver should not force MDB Tools on Unix platforms

Mateusz,

I'd appreciate it if you could consider this before the 1.4.0 release is finalized.

I understand that default installation of MDB Tools driver on Unix is not recommended.
I'm sure, I can check if there is any MDB driver already installed.
If there is one, OGR will not try to install it.

But I'm still not sure I understand what alternatives to MDB Tools we have, if any.

What MDB drivers can be used on Unix instead of MDB Tools?
What if there is no MDB tools and no other MDB driver is installed, then accessing Personal Geodatabase seems to be not possible. Am I correct?

Summarizing, we need ODBC layer + MDB tools driver to use OGR PGeo driver.
For Unix platforms (Linux mainly), we have tested unixODBC + MDB Tools.
What else ODBC and MDB drivers on Unix we can support?
If there are any, I will try to add their support and test with OGR.

William, I'm also going to try to make MDB Tools + unixODBC working on OSX but it may need some time.

Thanks for any suggestions!

Sounds like you have a good idea what's available for linux.  I'm thinking mainly of Mac OS X.  There is a commercial iODBC driver for Access from Actual (actualtechnologies.com).  Although I've been having a little trouble with it reading binary fields, but the developers of the driver are looking into it so it should work when bugs are worked out. (Note: I patch GDAL to use iODBC that comes with OSX.  I have a feature request for GDAL to add that as a config option.)

I looked at the MDB Tools with the thought of trying to build it on Mac OS X, but I was turned off by the Gnome requirements - glib and friends.  Tho it looks like I would just need glib for just the library without the extra tools.  There isn't a technical problem building glib, I've built it in the past on OSX, I'm just a lazy whiner.

But I have heard others say that they've had problems getting MDB Tools to work on OSX.

(In reply to comment #3)
> Sounds like you have a good idea what's available for linux.

Yes, this subject on Linux is pretty well tested.

> There is a commercial iODBC driver for Access from Actual
> (actualtechnologies.com).

First good news is that iODBC is called "Open Source platform" so I believe it's freely available.

The Access driver you've mentioned is commercial, so I believe if it is supposed to be supported, it should be optional for GDAL users.
Do you know if it's the only Access driver for Mac available or may there are 
other implementations, closed or open source?

Frank,
what do you think about adding support to OGR for iODBC + Access
driver from Actual Technologies?

> Although I've been having a little trouble with it
> reading binary fields, but the developers of the driver are looking into it so
> it should work when bugs are worked out. (Note: I patch GDAL to use iODBC that
> comes with OSX.  I have a feature request for GDAL to add that as a config
> option.)

Does it mean you've almost ready support for iODBC + Access driver from Actual Technologies?
 
> I looked at the MDB Tools with the thought of trying to build it on Mac OS X,
> but I was turned off by the Gnome requirements - glib and friends.

glib is the only requirement for MDB Tools driver.
I agree, it may not be good solution for most Mac users to require glib installation to use ODBC + Access on Mac.

> But I have heard others say that they've had problems getting MDB Tools
> to work on OSX.

I've also experienced unstable behavior of MDB Tools on Linux, so I assume it's not a mature driver yet.

Please, give me some time to discuss iODBC option.

William, if you are able to provide iODBC support patch for OGR PGeo driver, that would be great. I can assist you to include it into OGR.
I can also try to test it on Mac with trial version of AT's driver for Access.

Does it make sense for you?

What a coincidence, I just heard back from Actual today with a fixed Access driver.  I'm checking it out now, but I'm having trouble with the exportToWkt() function segfaulting, but at least it looks like it's reading binary data now.

For iODBC support option, first an option is configure is needed so iODBC is used in place of UnixODBC.  Basically -liodbc and -liodbcinst instead of -lodbc and -lodbcinst (quick-n-dirty method: find and replace).  Basic ODBC headers are the same, but the odbcinst header has a different name for iODBC, iodbcinst.h, so a switch is needed in port/cpl_odbc.h depending on the configed ODBC used to include the correct odbcinst header.

Note: I must have been thinking of GRASS for the iODBC feature request.  I didn't see one in the GDAL bug list.  So I guess this is a combined pgeo bug and iodbc request ^_^

Within the pgeo driver itself, it's automatic, as long as ogrpgeodriver.cpp doesn't try to register/install the MDB Tools driver (my quick hack was to comment that out).

Oh, and yes, this is the only non-bridge Access driver I was able to find for OSX.