Alvaro Herrera <[EMAIL PROTECTED]> writes: > Using Phantom Xids > ================== > The idea here is to use an approach similar to what we use now: mark the > tuples with an Xid when it is locked. A phantom Xid is a sort-of Xid, > with multiple real Xids associated to it. So we mark the tuple with the > regular Xid the first time the share lock is acquired; if a second > transaction wants to lock the tuple, it creates a new phantom Xid which > "contains" the original Xid in the tuple and its own Xid, insert it into > the phantom Xid table, and mark the tuple with that as Xmax.
That sounds like a fancy way to describe "make a linked list of lockers". -- greg ---------------------------(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