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Predefined collection types for Oracle PL/SQL

Two predefined collection types for Oracle PL/SQL are

Turning lists into tables

Such collection types are useful to transpose a list of values into a table:

select
   column_value as val
from
   sys.ku$_vcnt('one', 'two', 'three');

The intended purpose of dbms_debug_vc2coll is to pass data back to the caller of dbms_debug.execute (See source of dbmspb.sql).

The column name is column_value:

select
   t.column_value
from
   sys.dbms_debug_vc2coll('foo', 'bar', 'baz') t;

vcnt stands for varchar2 nested table and is a table of varchar2(4000).

ku$_vcnt also has a public synonym so that it is not required to prefix with sys:

select
   column_value as val
from
   ku$_vcnt('one', 'two', 'three');

Apparently, there is supposed to be a type named ku$_vcntbig which stores varchar2(32000), but I was unable to locate it.