32-bit versus 64-bit Datasources

If you are running a 32-bit edition of Windows, life is simple!

If you are running a 64-bit edition of Windows there are a number of issues you need to be aware of.

On 64-bit systems, ODBC Drivers will be either a 32-bit driver, or a 64-bit driver.

• Datasources using a 32-bit Driver will only work with 32-bit AQT
• Datasources using a 64-bit Driver will only work with 64-bit AQT

To manage these, Microsoft supply two ODBC Administrator programs:

• the 32-bit ODBC Datasource Administrator is in c:\Windows\SysWoW64\odbcad32.exe
• the 64-bit ODBC Datasource Administrator is in c:\Windows\system32\odbcad32.exe

When you click on ODBC Manager from the AQT Signon window, you will get the either the 32-bit or 64-bit ODBC Administrator, depending on the architecture of the AQT you are running.

If you are starting the Datasource Administrator from the Windows start bar you need to make sure you get the correct one! If you are running Windows 7 you will only get the 64-bit program. To add or manage 32-bit datasources you will need to manually run c:\Windows\SysWoW64\odbcad32.exe

An additional complication..

Both AQT and the ODBC Datasource Administator will show you:

• For System Datasources - only those which are appropriate for the architecture of the program you are running
• For User Datasources - all datasources irrespective of whether they are 32-bit or 64-bit

So... you will can be shown datasources which can't be used. If you try to use one of these you will get:

Data source name not found and no default driver specified

or

The specified DSN contains an architectural mismatch between the Driver and Application.