Window order clause

Specifies how to sort rows that are supplied to an analytic function. If the OVER clause also includes a window partition clause, rows are sorted within each partition.

The window order clause only specifies order within a window result set. The query can have its own ORDER BY clause outside the OVER clause. This has precedence over the window order clause and orders the final result set.

A window order clause also creates a default window frame if none is explicitly specified.

Syntax

ORDER BY { expression [ ASC | DESC [ NULLS { FIRST | LAST | AUTO } ] ]
  }[,...]

Arguments

expression

A column, constant, or arbitrary expression formed on columns on which to sort input rows.

ASC | DESC

Sort order: ascending (default) or descending.

NULLS {FIRST | LAST | AUTO}

How to position nulls. NULLS AUTO means to choose the positioning that is most efficient for this query.

ASC defaults to NULLS LAST and DESC defaults to NULLS FIRST.

If you omit all sort qualifiers, Vertica uses ASC NULLS LAST.

For more information, see NULL sort order and Runtime sorting of NULL values in analytic functions.

Examples

See Window ordering.