On Wednesday, 24 October 2012 18:26:15 UTC-4, Filipe Giusti wrote: > > Hi fellow programmers, > > I was looking for how to keep integrity in some financial transactions and > I saw this "This could even happen if you use transactions with the > ‘serializable’ isolation level." in the uniqueness page > http://api.rubyonrails.org/classes/ActiveRecord/Validations/ClassMethods.html#method-i-validates_uniqueness_of. > > How this is possible with the serializablo isolation level? Aren't the > select and update done in the same transaction? > > They are, but that doesn't prevent races like the one in the documentation from occurring - in that case, both transactions find no conflicting records and create a row.
As noted in the docs, if you really really need data consistency you're better off using a unique index and catching ActiveRecord::RecordNotUnique. --Matt Jones -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-talk+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msg/rubyonrails-talk/-/78ImtEq69WAJ. For more options, visit https://groups.google.com/groups/opt_out.
