I am trying to figure out what does CASCADE in below statement is supposed to do .

ALTER TYPE test_cascade_type ADD ATTRIBUTE (col2 VARCHAR2(4000)) CASCADE;

I tried creating a table with a column of user defined type and then tried to alter the TYPE with cascade option.

CREATE TYPE test_cascade_type AS OBJECT( col1 NUMBER);

CREATE TABLE test_cascade( col1 test_cascade_type);

ALTER TYPE test_cascade_type ADD ATTRIBUTE (col2 VARCHAR2(4000)) CASCADE;

But only the TYPE was altered . Nothing changed in the TABLE.