Mike Lewis escribió: > I am trying to make a trigger that updates a row once and only once per > transaction (even if this trigger gets fired multiple times). The general > idea is that for a user we have a version number. When we modify the > user's data, the version number is incremented then set on the object. We > only need to increment the version number once. > > I am thinking about doing something like: > > update user > set version=version+1 > where txid_current() != xmin and user_id = 352395; Uh, txid_current returns a 64 bit value, whereas xmin only stores the 32 least significant bits. They would certainly differ after a xid wraparound. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
