Ape seems to have some trouble with transactions. When a ZODB connection reads from a SQL database via Ape, a transaction starts implicitly. If the ZODB connection only reads and never writes, the SQL connection doesn't get registered in the transaction. So the SQL transaction is neither committed nor aborted until something happens to write to the database.

I'm not sure what to do about this. Hmm... perhaps I should arrange for the SQL connection to be registered in the transaction even when reading. But first, I should write a test that fails because SQL transactions get left open.