Endon.max

You're seeing just the function max, go back to Endon module for more information.
Link to this function

max(column, conditions \\ [])

View Source

Specs

max(String.t() | atom(), where_conditions()) :: float() | integer()

Get the maximum value of a given column.

conditions are anything accepted by where/2 (including a Ecto.Query.t/0).