SQLite is very easy to get started with. I loaded up a 9 Mb file of process data and the performance was pretty good after I indexed on the join columns (increased db file size to 15Mb).
Supports transactions, cursors, typed data. I *think* it is thread-safe, but I'm not positive. But it's great as a simple embedded SQL database. -- Paul -- http://mail.python.org/mailman/listinfo/python-list
