ORA-30484: missing window specification for this function

ORA-30484: missing window specification for this function

Oracle PL/SQL error message: ORA-30484: missing window specification for this function.

Cause:

All window functions should be followed by window specification, like () OVER ()

Solution:

Correct the syntax, then retry the operation.

Example:

select  name, price, 
rank() (order by price desc) course_rank
from course ;

Output:

ORA-30484: missing window specification for this function

Correct:

select  name, price, 
rank() over (order by price desc) course_rank
from course ;