Do I need to add an ID value to my objects?

I have all these nice object开发者_Python百科s set up and ready to be added to tables. How are the objects made unique when I say:

CREATE TYPE obj_table AS TABLE OF obj_type;

Do I need to create a table that pairs an item with an ID, and declare the ID to be the primary key, or is this somehow done implicitly?

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For PL/SQL nested tables (see documentation), the index number is implicit with the definition of the table and assigned as you insert items into your defined table.