Andrew Dunstan <[EMAIL PROTECTED]> writes: > How expensive is this going to be, especially for huge numbers of rows?
Certainly cheaper than firing a per-row trigger. > Would it be done for all queries, or just those with a per statement > trigger, or only when explicitly requested? Just when there's a per-statement AFTER trigger, I would think. One of the tricky parts is to minimize overhead if the trigger never actually asks for access to the rows. However, if all we do during the statement is build a possibly-lossy bitmap, I don't think the overhead will be bad. It might be interesting to think about reimplementing the RI triggers as per-statement, too ... regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster