Is it required to use the AS keyword to rename the result?

Screen Link: https://app.dataquest.io/m/574/introduction-to-sql/5/naming-results

Screens 5 and 6 are using the AS keyword to rename the result. But the query is working fine even if I don’t use the AS keyword.

SELECT 3+5+3+5 perimeter;

Is it required to use the AS keyword to rename the result?

It’s not required to use the AS keyword as it is an optional keyword. However, I would recommend you to use it as it can improve your query’s readability.

It is not much of a problem in small queries, but when the query gets big, not using the AS keyword can make your query difficult to read.