Some months ago I needed to find out if proper forward-only cursors were implemented in the ODBC driver for MySQL. I didn't go very far with the documentation, but I've been diving in its source code and within 30 minutes I knew everything there was to know about the subject.
Now, after years I haven't touched proprietary software at all, I've been asked to port dballe to use the Oracle ODBC driver.
I had a similar problem: find out how to use scrollable cursors with Oracle's
ODBC driver. The release notes (a file called ODBCRelnotesUS.htm that I
probably can't put online without their consent) say that they're implemented
since ages, but
SQLSetStmtAttr always
tells me that the driver does not support it. Maybe I have to enable it
somewhere? Maybe it's a bug?
I could have found out with one hour browsing this driver's source code, but
that wasn't available. Instead, I had to spend a whole day of trial and error,
google searching with all sort of keyword combinations, looking at strings
output on the .so libraries, and in the end I still don't
know.
That porting project is now stuck indefinitely, and my customers had to pay for a full day of fruitless work.
So, here's the reminder: If you base on 3rd party proprietary software, you can't provide a serious service.