On Mon, 2008-02-04 at 11:30 -0800, John Nagle wrote: > Restarting the MySQL instance changes the database. The entry "google.com" > disappears, and is replaced by "www.google.com". This must indicate a hanging > transaction that wasn't committed. > > But that transaction didn't come from the Python IDLE session I've been > making test calls from. Those queries should match the graphical client > exactly. > > So why don't they agree?
I don't have a definitive answer, but I do have a piece of generic advice. If two database sessions receive differing results, the cause could be any of the following factors: 1) One session is in a transaction, but the other is not. 2) Both sessions are in a transaction, but they are at different isolation levels. 3) Both sessions are in a transaction, but the transactions were started at different times. It's entirely possible that the graphical client was operating outside of a transaction, showing you phantom rows of a transaction in progress, whereas the Python IDLE session was inside a transaction at something like "read last committed" (or whatever MySQL calls it) isolation level. Any of the factors above determine which "snapshot" of the data will be visible to the database clients. Unless you are *absolutely certain* that both clients should have seen the exact same snapshot, it's really not all that weird that you are seeing discrepancies, especially in light of the fact that you had an uncommitted transaction hanging around somewhere. Hope this helps, -- Carsten Haese http://informixdb.sourceforge.net -- http://mail.python.org/mailman/listinfo/python-list
