Rownum in Oracle for filtering

 It's a traditional question in Oracle:

  How to select the 11th record to the 20 th record in a database table.
A. The simplest form:
  How to select the 1 to 10 records.
  Just the following sql:
  SELECT * FROM ta WHERE rownum < 11
  will select the first 10 records if there are 10 or more records in the database.
  SELECT 1 FROM ta WHERE rownum < 11
  will select 10 ones if there are 10 or more records in the database, if there is no record in the database, there will be no records returned by the SQL.

B. How to select the 11th to 20 th records.
  Please don't use :
  SELECT * FROM ta WHERE rownum BETWEEN 11 AND 21
    between means 11<=x<=21
  The statement will return no record. it's because the rownum of the statement begins with 0 and is a virtual column, it will add 1 unit a new row is caught. So, from beginning, the rownum will never meet the condition.
  Let's use another way:
 SELECT * FROM ( 
( SELECT T.*, ROWNUM ROWCOUNTER FROM ta T WHERE rownum <21 )
  ) WHERE ROWCOUNTER > 10

  Once, I thought the following statement may works:
   ( SELECT t.ctr_cont_no FROM ta WHERE rownum < 21 )
   MINUS
   (SELECT t.ctr_cont_no FROM ta WHERE rownum < 11)
  but it turns out the MINUS operator is an set operator, so the result may have less than 10 results. So use the following instead:
  (SELECT t.rowid, t.ctr_cont_no FROM ta WHERE ROWNUM <21 )
   MINUS
  (SELECT t.rowid,t.ctr_cont_no FROM ta WHERE ROWNUM < 11)
 it works but with an additional column.
  For
  (SELECT T.* FROM ta WHERE rownum < 21)
  MINUS
  (SELECT T.* FROM ta WHWER rownum < 10)
 I don't know the exact, then have the following test.
  create a single column table:
   create table sin_column_test (COLUMN1 NUMBER NOT NULL);
   insert into sin_column_test select 10 from all_objects where rownum <=100;

  issue the command:
    (select * from sin_column_test where rownum< 21 )
   minus
  (select * from sin_column_test where rownum < 11)

 There is no record returned. So T.* only means the columns defined in the DML SQL, not any virtual columns are included.