try_sum aggregate function
Applies to: 
Databricks SQL Databricks Runtime 11.3 LTS and above
Returns the sum calculated from values of a group, or NULL if there is an overflow.
Syntax
try_sum ( [ALL | DISTINCT] expr ) [FILTER ( WHERE cond ) ]
This function can also be invoked as a window function using the OVER clause.
Arguments
expr: An expression that evaluates to a numeric or interval.cond: An optional boolean expression filtering the rows used for aggregation.
Returns
If expr is an integral number type, a BIGINT.
If expr is DECIMAL(p, s) the result is DECIMAL(p + min(10, 31-p), s).
If expr is an interval the result type matches expr.
Otherwise, a DOUBLE.
If DISTINCT is specified only unique values are summed up.
If the result overflows the result type Databricks SQL returns NULL. To return an error instead use sum.
Examples
> SELECT try_sum(col) FROM VALUES (5), (10), (15) AS tab(col);
30
> SELECT try_sum(col) FILTER(WHERE col <15)
FROM VALUES (5), (10), (15) AS tab(col);
15
> SELECT try_sum(DISTINCT col) FROM VALUES (5), (10), (10), (15) AS tab(col);
30
> SELECT try_sum(col) FROM VALUES (NULL), (10), (15) AS tab(col);
25
> SELECT try_sum(col) FROM VALUES (NULL), (NULL) AS tab(col);
NULL
-- try_sum overflows a BIGINT
> SELECT try_sum(c1) FROM VALUES(5E18::BIGINT), (5E18::BIGINT) AS tab(c1);
NULL
-- In ANSI mode sum returns an error if it overflows BIGINT
> SELECT sum(c1) FROM VALUES(5E18::BIGINT), (5E18::BIGINT) AS tab(c1);
ERROR
-- try_sum overflows an INTERVAL
> SELECT try_sum(c1) FROM VALUES(INTERVAL '100000000' YEARS), (INTERVAL '100000000' YEARS) AS tab(c1);
NULL
-- sum returns an error on INTERVAL overflow
> SELECT sum(c1) FROM VALUES(INTERVAL '100000000' YEARS), (INTERVAL '100000000' YEARS) AS tab(c1);
Error: ARITHMETIC_OVERFLOW