Empty OVER() clause is supported in PostgreSQL (no PARTITION BY or ORDER BY between parenthesis). I don't know if MariaDB is going to support it. However, if it doesn't, I'd expect an error message. Instead, the server simply hangs. No query is being executed, but the client freezes without showing any results or errors.

CREATE OR REPLACE TABLE t

(

         num INT UNSIGNED NOT NULL

)

         ENGINE InnoDB

;

INSERT INTO t VALUES (1), (2), (3);

SELECT

num, SUM(num) OVER () AS sum_salary

FROM t;