ORDER BY Clause

Sorts a query result set on one or more columns or column expressions. Vertica uses the current locale and collation sequence to compare and sort string values.

Vertica projection data is always stored sorted by the ASCII (binary) collating sequence.

Syntax

ORDER BY expression [ ASC | DESC ] [,...]

Parameters

expression

One of the following:

  • Name or ordinal number of a SELECT list item. The ordinal number refers to the position of the result column, counting from the left beginning at one. Use them to order by a column whose name is not unique. Ordinal numbers are invalid for an ORDER BY clause of an analytic function's OVER clause.
  • Arbitrary expression formed from columns that do not appear in the SELECT list
  • CASE expression.

You cannot use DISTINCT on a collection column if it is also included in the sort order.

ASC | DESC

Specifies whether to sort values in ascending or descending order. NULL values are either first or last in the sort order, depending on data type:

  • INTEGER, INT, DATE/TIME: NULL has the smallest value.
  • FLOAT, BOOLEAN, CHAR, VARCHAR, ARRAY, SET: NULL has the largest value

Examples

The follow example returns all the city and deal size for customer Metamedia, sorted by deal size in descending order.

=> SELECT customer_city, deal_siz FROM customer_dimension WHERE customer_name = 'Metamedia'
   ORDER BY deal_size DESC;	
  customer_city   | deal_size
------------------+-----------
 El Monte         |   4479561
 Athens           |   3815416
 Ventura          |   3792937
 Peoria           |   3227765
 Arvada           |   2671849
 Coral Springs    |   2643674
 Fontana          |   2374465
 Rancho Cucamonga |   2214002
 Wichita Falls    |   2117962
 Beaumont         |   1898295
 Arvada           |   1321897
 Waco             |   1026854
 Joliet           |    945404
 Hartford         |    445795
(14 rows)

The following example uses a transform function. It returns an error because the ORDER BY column is not in the window partition.

=> CREATE TABLE t(geom geometry(200), geog geography(200)); 
=> SELECT PolygonPoint(geom) OVER(PARTITION BY geom) 
   AS SEL_0 FROM t ORDER BY geog;
ERROR 2521: Cannot specify anything other than user defined transforms and partitioning expressions in the ORDER BY list

The following example, using the same table, corrects this error.

=> SELECT PolygonPoint(geom) OVER(PARTITION BY geom) 
   AS SEL_0 FROM t ORDER BY geom;

The following example uses an array in the ORDER BY clause.

=> CREATE TABLE employees (id INT, department VARCHAR(50), grants ARRAY[VARCHAR], grant_values ARRAY[INT]);

=> COPY employees FROM STDIN;
42|Physics|[US-7376,DARPA-1567]|[65000,135000]
36|Physics|[US-7376,DARPA-1567]|[10000,25000]
33|Physics|[US-7376]|[30000]
36|Astronomy|[US-7376,DARPA-1567]|[5000,4000]
\.

=> SELECT * FROM employees ORDER BY grant_values;
 id | department |          grants          |  grant_values
----+------------+--------------------------+----------------
 36 | Astronomy  | ["US-7376","DARPA-1567"] | [5000,4000]
 36 | Physics    | ["US-7376","DARPA-1567"] | [10000,25000]
 33 | Physics    | ["US-7376"]              | [30000]
 42 | Physics    | ["US-7376","DARPA-1567"] | [65000,135000]
(4 rows)