Question

How to create a table that contains a single column of date data type, that consists of all days starting from Jan 1, 2000 until today in oracle SQL

Answer 1

You can use a Oracle row generator:

 insert into your_table ( your_column )
 select 
    to_date('2000/01/01', 'yyyy/mm/dd') + N.n
 from
  (SELECT ROWNUM n
   FROM   ( SELECT 1 just_a_column
         FROM   dual
         CONNECT BY LEVEL <= 
               SYSDATE
               - to_date('2000/01/01', 'yyyy/mm/dd') 
               + 1
           ) T
  ) N
  where
      to_date('2000/01/01', 'yyyy/mm/dd') + N.n <= SYSDATE