📄️ CREATE FUNCTION
CREATE FUNCTION creates a user-defined function (UDF). Currently, you can only create Java UDFs, including Scalar functions, user-defined aggregate functions (UDAFs), user-defined window functions (UDWFs), and user-defined table functions (UDTFs).
📄️ DROP FUNCTION
Description
📄️ SHOW FUNCTIONS
SHOW FUNCTIONS queries all the custom (or built-in) functions under a database. If no database is specified, the current database is used by default.