title: Get next row of cursor in a loop without moving the index of cursor in PL/SQL
body: <p>I am working on Oracle procedure where I have to calculate time difference  between two rows
  time is present as column in cursor.
  For this I will have to loop over a cursor and get the current row and next row and calculate the time difference.
  How can I do this in loop ?
  How can I get the next row cursor without moving a cursor?</p>