This is the documentation for CDH 5.1.x. Documentation for other versions is available at Cloudera Documentation.

MAX Function

An aggregate function that returns the maximum value from a set of numbers. Opposite of the MIN function. Its single argument can be numeric column, or the numeric result of a function or expression applied to the column value. Rows with a NULL value for the specified column are ignored. If the table is empty, or all the values supplied to MAX are NULL, MAX returns NULL.

When the query contains a GROUP BY clause, returns one value for each combination of grouping values.

Return type: Same as the input argument

Examples:

-- Find the largest value for this column in the table.
select max(c1) from t1;
-- Find the largest value for this column from a subset of the table.
select max(c1) from t1 where month = 'January' and year = '2013';
-- Find the largest value from a set of numeric function results.
select max(length(s)) from t1;
-- Can also be used in combination with DISTINCT and/or GROUP BY.
-- Return more than one result.
select month, year, max(purchase_price) from store_stats group by month, year;
-- Filter the input to eliminate duplicates before performing the calculation.
select max(distinct x) from t1;
Page generated September 3, 2015.