#9964: Transaction middleware closes the transaction only when it's marked as
dirty
------------------------------------------+---------------------------------
Reporter: ishirav | Owner: nobody
Status: new | Milestone:
Component: Database layer (models, ORM) | Version: 1.0-beta-1
Keywords: transactions | Stage: Unreviewed
Has_patch: 0 |
------------------------------------------+---------------------------------
The transaction middleware commits only dirty transactions on success, and
rolls back only dirty transactions in case of an error.
This means that any transaction that only SELECTs data gets rolled back
(I'm not sure by whom - the database itself, perhaps?). So this is what I
see in my PostgreSQL log:
{{{
BEGIN; SET TRANSACTION ISOLATION LEVEL READ COMMITTED
SET TIME ZONE E'America/Chicago'
SELECT ...
SELECT ...
SELECT ...
ROLLBACK
}}}
The expected behavior is a COMMIT (except in case of an error).
Typically this does not cause any problems, because it affects only non-
dirty transactions.
However if you use raw SQL to make database modifications, it will be
rolled back unless the dirty flag gets set by some another part of your
code. This can result in loss of data, and a very hard to find bug...
The correct behavior would be to always close the transaction, regardless
of the dirty flag. Meaning that TransactionMiddleware.process_response
should always call transaction.commit(), and
TransactionMiddleware.process_exception should always call
transaction.rollback()
This bug is also the cause of tickets #9763 and #9919
--
Ticket URL: <http://code.djangoproject.com/ticket/9964>
Django <http://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Django updates" group.
To post to this group, send email to django-updates@googlegroups.com
To unsubscribe from this group, send email to
django-updates+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/django-updates?hl=en
-~----------~----~----~----~------~----~------~--~---
