elasticsearch/docs/reference/query-languages/esql/_snippets/functions/mv_max.md

MV_MAX [esql-mv_max]

Syntax

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Parameters

field : Multivalue expression.

Description

Converts a multivalued expression into a single valued column containing the maximum value.

Supported types

field	result
boolean	boolean
date	date
date_nanos	date_nanos
double	double
integer	integer
ip	ip
keyword	keyword
long	long
text	keyword
unsigned_long	unsigned_long
version	version

Examples

ROW a=[3, 5, 1]
| EVAL max_a = MV_MAX(a)

a:integer	max_a:integer
[3, 5, 1]	5

It can be used by any column type, including keyword columns. In that case it picks the last string, comparing their utf-8 representation byte by byte:

ROW a=["foo", "zoo", "bar"]
| EVAL max_a = MV_MAX(a)

a:keyword	max_a:keyword
["foo", "zoo", "bar"]	"zoo"