Whereas tuples are specified ad hoc when declaring the type for a column, user-defined types are defined separately and then referred to by name in column definitions. Let's make a user-defined type that we can use for our education column:
CREATE TYPE "education_information" ( "school_name" text, "graduation_year" int );
Just like the tuple, we declared for our education column, this user-defined type contains two fields: a string containing the name of an educational institution, and an integer containing a year of graduation. Unlike the tuple, the type is declared independently of any particular table or column; it is a first-class entity within the my_status keyspace. This is advantageous when we want ...
