What does the MERGE command do? I have never heard of it, so I doubt someone is working on it.
It is basically the SQL standard version of MySQL's REPLACE syntax. It does an update-else-insert set. However, the trick is that it uses some sort of next key locking to ensure that it cannot fail. Something that is impossible to do in PostgreSQL at the moment. Nested transactions will help, however.
Chris
---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
