On 12/21/07, Jeremy Kemper <[EMAIL PROTECTED]> wrote: > > On 12/21/07, pipa <[EMAIL PROTECTED]> wrote: > > As far as I can judge locking FOR UPDATE can effectively save us from > > the burden of parse-db-error-messages-and-retry approach, provided > > that unique index is set on the corresponding column of course. > > I dream I could do like this: > > validates_uniqueness_of :something, :lock => true > > and this would use the statements like the following: > > SELECT .... WHERE something = ? FOR UPDATE > > INSERT .... > > This is not equal to table-level locking as in our case (uniqueness > > checking) only access to a certain index gap is serialized and neither > > other gaps nor existing rows are locked. > > That's cool. I thought FOR UPDATE wouldn't prevent inserts.
It doesn't. It locks all the rows it selects, but since there's no row yet, there's nothing to lock. Assaf > Is this > also true for the other databases we support? > > jeremy > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Core" group. To post to this group, send email to rubyonrails-core@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/rubyonrails-core?hl=en -~----------~----~----~----~------~----~------~--~---
