[ZODB-Dev] summary of version discussion

[Jeremy Hylton]

>>>>> "GW" == Greg Ward <gward@mems-exchange.org> writes:

  GW> On 05 December 2002, Jeremy Hylton said:
  >> I'm probably the primary advocate of versions.  My rationale is
  >> that the locking feature of versions allows long-running actions
  >> to be performed in a transactional manner.  Since ZODB uses
  >> optimistic concurrency control, a long-running transaction has a
  >> higher chance of failing with a conflict error.  In the extreme,
  >> it could be impossible to commit a long-running transaction
  >> because some other transaction would always introduce a conflict.

  GW> It sounds to me like the right name is "locking transaction".
  GW> Or maybe "pessimistic transaction".  "Long-running transaction"
  GW> is a possibility, but that just describes the intended use, not
  GW> the actual behaviour.  Whatever, I'm pretty sure it's a kind of
  GW> transaction.  (But I'm a database ignoramus.)

I'm not sure I was looking for a proper name.  The description
long-running transaction was just an attempt to characterize a kind of
transaction that isn't likely to work.  A ZODB version is not a single
transaction, so it shouldn't get the name transaction anywhere.

Jeremy