MULTISET is a collection type in which duplicated elements are allowed. Elements of a MULTISET can have many different data types or even instances of different classes.
CREATE TABLE multiset_tbl ( col_1 multiset(int, CHAR(1)));
INSERT INTO multiset_tbl VALUES ({3,3,3,2,2,1,0,'c','c','c','b','b', 'a'});
SELECT * FROM multiset_tbl;
col_1
======================
{0, 1, 2, 2, 3, 3, 3, 'a', 'b', 'b', 'c', 'c', 'c'}
SELECT CAST(col_1 AS SET), CAST(col_1 AS LIST) FROM multiset_tbl;
cast(col_1 as set) cast(col_1 as sequence)
============================================
{0, 1, 2, 3, 'a', 'b', 'c'} {3, 3, 3, 2, 2, 1, 0, 'c', 'c', 'c', 'b', 'b', 'a
'}