ROW_NUMBER [Analytic]

Assigns a sequence of unique numbers to each row in a window partition, starting with 1. ROW_NUMBER and RANK are generally interchangeable, with the following differences:

  • ROW_NUMBER assigns a unique ordinal number to each row in the ordered set, starting with 1.
  • ROW_NUMBER() is a Vertica extension, while RANK conforms to the SQL-99 standard.

Behavior Type

Immutable

Syntax

ROW_NUMBER () OVER ( 
    [ window-partition-clause ] 
    [ window-order-clause ] )

Parameters

OVER() See Analytic Functions

Examples

The following ROW_NUMBER query partitions customers in the VMart table customer_dimension by customer_region. Within each partition, the function ranks those customers in order of seniority, as specified by its window order clause:

=> SELECT * FROM 
    (SELECT ROW_NUMBER() OVER (PARTITION BY customer_region ORDER BY customer_since) AS most_senior, 
     customer_region, customer_name, customer_since FROM public.customer_dimension WHERE customer_type = 'Individual') sq 
   WHERE most_senior <= 5;
 most_senior | customer_region |    customer_name     | customer_since
-------------+-----------------+----------------------+----------------
           1 | West            | Jack Y. Perkins      | 1965-01-01
           2 | West            | Linda Q. Winkler     | 1965-01-02
           3 | West            | Marcus K. Li         | 1965-01-03
           4 | West            | Carla R. Jones       | 1965-01-07
           5 | West            | Seth P. Young        | 1965-01-09
           1 | East            | Kim O. Vu            | 1965-01-01
           2 | East            | Alexandra L. Weaver  | 1965-01-02
           3 | East            | Steve L. Webber      | 1965-01-04
           4 | East            | Thom Y. Li           | 1965-01-05
           5 | East            | Martha B. Farmer     | 1965-01-07
           1 | SouthWest       | Martha V. Gauthier   | 1965-01-01
           2 | SouthWest       | Jessica U. Goldberg  | 1965-01-07
           3 | SouthWest       | Robert O. Stein      | 1965-01-07
           4 | SouthWest       | Emily I. McCabe      | 1965-01-18
           5 | SouthWest       | Jack E. Miller       | 1965-01-25
           1 | NorthWest       | Julie O. Greenwood   | 1965-01-08
           2 | NorthWest       | Amy X. McNulty       | 1965-01-25
           3 | NorthWest       | Kevin S. Carcetti    | 1965-02-09
           4 | NorthWest       | Sam K. Carcetti      | 1965-03-16
           5 | NorthWest       | Alexandra X. Winkler | 1965-04-05
           1 | MidWest         | Michael Y. Meyer     | 1965-01-01
           2 | MidWest         | Joanna W. Bauer      | 1965-01-06
           3 | MidWest         | Amy E. Harris        | 1965-01-08
           4 | MidWest         | Julie W. McCabe      | 1965-01-09
           5 | MidWest         | William . Peterson   | 1965-01-09
           1 | South           | Dean . Martin        | 1965-01-01
           2 | South           | Ruth U. Williams     | 1965-01-02
           3 | South           | Steve Y. Farmer      | 1965-01-03
           4 | South           | Mark V. King         | 1965-01-08
           5 | South           | Lucas Y. Young       | 1965-01-10
(30 rows)

See Also