elasticsearch/docs/reference/esql/functions/mv_max.asciidoc

[[esql-mv_max]]
=== `MV_MAX`
Converts a multivalued field into a single valued field containing the maximum value. For example:

[source.merge.styled,esql]
----
include::{esql-specs}/math.csv-spec[tag=mv_max]
----
[%header.monospaced.styled,format=dsv,separator=|]
|===
include::{esql-specs}/math.csv-spec[tag=mv_max-result]
|===

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

[source.merge.styled,esql]
----
include::{esql-specs}/string.csv-spec[tag=mv_max]
----
[%header.monospaced.styled,format=dsv,separator=|]
|===
include::{esql-specs}/string.csv-spec[tag=mv_max-result]
|===