The first type of collection is known as index-by tables. These behave in the same way as arrays except that have no upper bounds, allowing them to constantly extend. As the name implies, the collection is indexed using
PL/SQL tables help you move bulk data. They can store columns or rows of Oracle data, and they can be passed as parameters. So, PL/SQL tables make it easy to move collections of data into and out of database tables or between client-side applications and stored subprograms. You can even use PL/SQL tables of records to simulate local database tables.
examples:
BINARY_INTEGER values, which do not need to be consecutive. The collection is extended by assigning values to an element using an index value that does not currently exist.PL/SQL tables help you move bulk data. They can store columns or rows of Oracle data, and they can be passed as parameters. So, PL/SQL tables make it easy to move collections of data into and out of database tables or between client-side applications and stored subprograms. You can even use PL/SQL tables of records to simulate local database tables.
examples:
TYPE EnameType IS TABLE OF emp.ename%TYPE
or
TYPE table_type IS TABLE OF NUMBER(10)
