length of recordset read through a cursor

After declaring a cursor, one way of obtaining the length of the resultset 
is to perform a "MOVE 0" and read the PQcmdStatus which returns a "MOVE nn" 
where nn is the length of the resultset. (A negative MOVE can then be  used 
to allow starting to fetch records from the beginning of the resultset.)

Is there another, possibly faster way?

Thanks, K.P.Lehre