date value 18/5/2010, 1 pm 40 18/5/2010, 2 pm 20 18/5/2010, 3 pm 60 18/5/2010, 4 pm 30 18/5/2010, 5 pm 60 18/5/20
Analytics! This avoids having to access the table twice:
SELECT DISTINCT FIRST_VALUE(date_col) OVER (ORDER BY value_col DESC, date_col ASC), FIRST_VALUE(value_col) OVER (ORDER BY value_col DESC, date_col ASC) FROM mytable;