ODBC on x64-Machines
Article created 2007-09-07 by Rainer Gerhards.
Microsoft provides integration of 32bit software into the 64 bit world.
They have worked quite hard to make any differences invisible to the user and
even the programmer. However, there are some subtleties that cannot be totally
hidden. One of them can be experienced in the ODBC subsystem.There are
actually two ODBC subsystems in 64bit-Windows - one for the 64 bit world and
one for the 32 bit world. This is necessary, because there were a number of
changes that prevented 32 bit drivers from running in the 64 bit environment. In
general, these two worlds are quite transparent to the user. However, there are
some restrictions:
- Drivers can not be shared between worlds. Most importantly, that
means that many ODBC drivers (e.g. JET) are not available to 64 bit ODBC
programs
- Changes to the ODBC configuration made with 32 bit tools affect only the
32 bit world - and vice versa
In practice, these two restrictions limit the utility of ODBC on 64 bit
Windows versions. This comes at no surprise, given that Mícrosoft has
declared ODBC to be legacy some years ago and is actively promoting OLEDB (where
there is a rich choice of drivers available).
When working with ODBC, please keep these restrictions on your mind. For
best results, we recommend using OLEDB functionality, which is available in
Adiscon products. OLEDB also offers a better performance.
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