A functionName represents a Java function. To create a function, use
the .
Syntax[ schemaName. ] SQLIdentifier
You can qualify a function name with a schemaName. If a qualified
function name is specified, the schema name cannot begin with SYS.
Example-- Declaring a scalar function
CREATE FUNCTION TO_DEGREES
( RADIANS DOUBLE )
RETURNS DOUBLE
PARAMETER STYLE JAVA
NO SQL LANGUAGE JAVA
EXTERNAL NAME 'java.lang.Math.toDegrees';