James Henstridge wrote at 2008-1-22 20:33 +0900: > ... >I do see a use for the branch qualifier though. In a distributed >transaction, each resource should have a different transaction ID
Why? Why is it not equally good to use a common transaction id for all resource managers? >that >share a common global transaction ID but separate branch qualifiers. > >As transaction IDs are global within database clusters for some >backends (PostgreSQL, MySQL and probably others), the branch qualifier >is necessary if two databases from the cluster are used in the global >transaction. They refer to the same transaction -- even when several databases in a cluster are affected. The transaction as a whole will want to get prepared, committed, rolledback... -- Dieter _______________________________________________ DB-SIG maillist - DB-SIG@python.org http://mail.python.org/mailman/listinfo/db-sig
