"wangshj" <[EMAIL PROTECTED]> writes: > Description: System column oid is not unique
There isn't, and never has been nor will be, any promise that it is, except to the extent that uniqueness is enforced by a unique index on a particular table. OID is just a kind of serial sequence generator. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match