Hi, I have an O/R mapping thingy that's written outside of Zope. Because I want to make it a good citizen when it is called by e.g. a Zope product, I've extended it to use Z Database connections; more specifically, it assumes psycopg (metadata intepretation under Python is quite driver dependent, it seems...). Because psycopg is advertised as having a per-cursor commits, initially I just did the same thing in my code as a Z SQL Method would do: call the database object for a connection and run query() on it. However, it turned out that when multiple threads did this, one thread's commit would also commit work on another thread. This is probably due to the fact that the psycopg DB class commits on the connection, not on the cursor it used. So I now grab a cursor, and register that (inside a wrapper) with the transaction manager, for every query. The finish/abort code does a commit/rollback and then a cursor.close() (shortly after that, the GC destroys the cursor). However, I seem to be leaking connections, because the number of in-use connections quickly goes up and Postgres starts complaining. There's probably some interaction between what I do and psycopg that I don't understand. Would anyone have a suggestion as to how I could use psycopg Z Database connections from Python code in such a way that everything works smoothly? What's the Zope model anyway - does it instantiate one Z connection per thread or do all the threads use the same connection and should the connection figure it out by itself? -- Cees de Groot http://www.cdegroot.com <cg@cdegroot.com> GnuPG 1024D/E0989E8B 0016 F679 F38D 5946 4ECD 1986 F303 937F E098 9E8B