Updating the records in to the cursor
But, when you retrieve the nested table into a PL/SQL variable, the rows are given consecutive subscripts starting at 1.
That gives you array-like access to individual rows.
PL/SQL nested tables are like one-dimensional arrays.
You can model multi-dimensional arrays by creating nested tables whose elements are also nested tables.
PL/SQL offers these collection types: Although collections can have only one dimension, you can model multi-dimensional arrays by creating collections whose elements are also collections.
To use collections in an application, you define one or more PL/SQL types, then define variables of those types.
Within the database, nested tables can be considered one-column database tables.
To support these techniques in database applications, PL/SQL provides the datatypes , which allow you to declare index-by tables, nested tables and variable-size arrays.You must update or retrieve all elements of the varray at the same time, which is most appropriate when performing some operation on all the elements at once.But you might find it impractical to store and retrieve large numbers of elements this way.You can define collection types in a procedure, function, or package.
You can pass collection variables as parameters, to move data between client-side applications and stored subprograms.Nested tables can be sparse: you can delete arbitrary elements, rather than just removing an item from the end.