Oracle: ‘= ANY()’ vs. ‘IN ()’

Question

ANY (or its synonym SOME) is a syntax sugar for EXISTS with a simple correlation:

SELECT  *
FROM    mytable
WHERE   x <= ANY
        (
        SELECT  y
        FROM    othertable
        )

is the same as:

SELECT  *
FROM    mytable m
WHERE   EXISTS
        (
        SELECT  NULL
        FROM    othertable o
        WHERE   m.x <= o.y
        )

With the equality condition on a not-nullable field, it becomes similar to IN.

All major databases, including SQL Server, MySQL and PostgreSQL, support this keyword.