Installation guide

mxODBC - Python ODBC Database Interface

5.4 Thread Safety & Thread Friendliness

mxODBC itself is written in a thread safe way. There are no module globals being

used and thus no locking is necessary.

5.4.1 Connections and Cursors

In general when using a separate database connection for each thread, you

shouldn't run into threading problems. If you do, it is more likely that the ODBC

driver is not 100% thread safe and thus not 100% ODBC compatible. Note that

having threads share cursors is not a good idea: there are many very strange

transaction related problems you can then run into.

5.4.2 Unlocking the Python Global Interpreter Lock (GIL)

Many of the underlying ODBC SQL function calls are wrapped by macros

unlocking the global Python interpreter lock before the call and regaining that lock

directly afterwards. The most prominent of those are the connection APIs and the

execute and fetch APIs.

Unlocking the interpreter lock during long SQL function calls gives your

application more responsiveness. This is especially important for GUI based

applications, since no other Python thread can run when the global lock is

acquired by one thread.

5.4.3 Threading Support

mxODBC will only support threading if you have built Python itself with thread

support enabled. Python for Windows and most recent Python versions for Unix

have this enabled per default. Try:

python -c "import threading" to find out.

If you get an exception, thread support is not available.

5.5 Transaction Support

5.5.1 Auto-Commit

ODBC uses auto-commit on new connections per default. This means that all SQL

statement executes will directly have an effect on the underlying database even in