Comments on: Transaction Management in Django http://blogs.gnome.org/jamesh/2008/09/01/transaction-management-in-django/ Random stuff Wed, 28 Oct 2009 02:53:32 +0800 http://wordpress.org/?v=2.8.6 hourly 1 By: James Henstridge http://blogs.gnome.org/jamesh/2008/09/01/transaction-management-in-django/comment-page-1/#comment-725 James Henstridge Mon, 08 Sep 2008 07:57:40 +0000 http://blogs.gnome.org/jamesh/2008/09/01/transaction-management-in-django/#comment-725 The problem is with enter_transaction_managemnt/leave_transaction_management nesting rather than with the individual decorators or the middleware class. My contention is that if you're in managed transaction mode and call enter_transaction_management(), it should not be possible to end the transaction until after calling leave_transaction_management() since doing so will split the transaction that was being managed. So @commit_manually has the same problems as the other decorators. Concentrating on the database side of things, an equivalent of Zope's transaction.doom() might be enough. If you've got code that has side effects outside of the database transaction, you need a way for that code to participate in the transaction commit/rollback (one example is sending out an email related to some DB changes). At that point you've essentially got Zope's transaction manager and may as well reuse that code directly. The problem is with enter_transaction_managemnt/leave_transaction_management nesting rather than with the individual decorators or the middleware class.

My contention is that if you’re in managed transaction mode and call enter_transaction_management(), it should not be possible to end the transaction until after calling leave_transaction_management() since doing so will split the transaction that was being managed. So @commit_manually has the same problems as the other decorators.

Concentrating on the database side of things, an equivalent of Zope’s transaction.doom() might be enough. If you’ve got code that has side effects outside of the database transaction, you need a way for that code to participate in the transaction commit/rollback (one example is sending out an email related to some DB changes). At that point you’ve essentially got Zope’s transaction manager and may as well reuse that code directly.

]]> By: Bob Haugen http://blogs.gnome.org/jamesh/2008/09/01/transaction-management-in-django/comment-page-1/#comment-724 Bob Haugen Mon, 08 Sep 2008 05:16:58 +0000 http://blogs.gnome.org/jamesh/2008/09/01/transaction-management-in-django/#comment-724 What (if anything) do you think is wrong with Django's @transaction.commit_manually decorator? If anything, would you please post a sample of the code you use to wrap transactions for managed transaction mode? What (if anything) do you think is wrong with Django’s @transaction.commit_manually decorator?

If anything, would you please post a sample of the code you use to wrap transactions for managed transaction mode?

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