Aggregate semi-structured functions work globally on all the arrays in a given column expression, instead of a row-by-row application.
At their simplest form (without a
GROUP BY clause) - they will provide the result of globally applying the function on all of the elements of the arrays in the column expression specified as their argument. For example,
ARRAY_SUM_GLOBAL will return the sum of all the elements in all the array of the given column.
ARRAY_MAX_GLOBAL will return the maximum element among all of the elements in all of the arrays in the given column expression.
When combined with a
GROUP BY clause, these operations will be performed on all of the arrays in each group.