On 4 mars 2013, at 04:04, Shai Berger <[email protected]> wrote: > you need to be sure that, in all these places, either reads don't > really affect consequent writes, or some constraint holds that is equivalent > to > serializability -- otherwise, negative effect is possible.
PostgreSQL and Oracle use the "repeatable read" isolation level by default. They are immune to this problem, because a sequence of reads followed by a write has the same semantics with a transaction under "read committed" and without a transaction. MySQL uses "read committed" and SQLite uses "serializable". Users of these databases may see a different behavior. I'm going to add this to the list of backwards incompatibilities: https://github.com/aaugustin/django/commit/876fddb68dd6990e87b15e683c498e41f8921f14#L4R437 ("Using unsupported database features" isn't correct for MySQL and SQLite right now.) Let me know if you think of other cases which I haven't covered! -- Aymeric. -- You received this message because you are subscribed to the Google Groups "Django developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/django-developers?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
