http://www.postgresqltutorial.com/postgresql-row_number/
ROW_NUMBER() OVER(
    [PARTITION BY column_1, column_2,…]
    [ORDER BY column_3,column_4,…]
)
http://www.postgresqltutorial.com/postgresql-row_number/
ROW_NUMBER() OVER(
    [PARTITION BY column_1, column_2,…]
    [ORDER BY column_3,column_4,…]
)