Add records in the beginning of the table

Question

Hi,
Is that possible to add or append the records in the beginning of the table.
For example,
   CREATE TABLE app_test (n NUMBER, n1 VARCHAR2(200));
   and inserting new records
  INSERT INTO app_test
     VALUES (1, 'test');
  INSERT INTO app_test
     VALUES (2, 'test');
  INSERT INTO app_test
     VALUES (3, 'test');
  select * from app_test;
N     N1
1     test
2     test
3     test
  Is that possible to add the records like below. Appending newly inserted rows in the beginning of the table.
N     N1
3     test
2     test
1     test
  Thanks
Radha K

Answer 1

hI,
Radha K wrote:
To get achieve sorting order, i have done the following, but the when i
query the record, its not showing the order which i created in the index.
CREATE TABLE iot_app_test (
n NUMBER,
n1 VARCHAR2(10),
n2 TIMESTAMP);
CREATE INDEX
iot_app_test_indx
ON
iot_app_test
SUBSTR(n2,1,9) DESC, SUBSTR(n2,11) ASC);
INSERT INTO iot_app_test
VALUES (1, 'test', SYSDATE);
INSERT INTO iot_app_test
VALUES (2, 'test', SYSDATE);
INSERT INTO iot_app_test
VALUES (3, 'test', SYSDATE);
INSERT INTO iot_app_test
VALUES (1, 'test', SYSDATE + 1);
INSERT INTO iot_app_test
VALUES (2, 'test', SYSDATE + 1);
INSERT INTO iot_app_test
VALUES (3, 'test', SYSDATE + 1);
INSERT INTO iot_app_test
VALUES (1, 'test', SYSDATE + 2);
INSERT INTO iot_app_test
VALUES (2, 'test', SYSDATE + 2);
INSERT INTO iot_app_test
VALUES (3, 'test', SYSDATE + 2);
SELECT *
FROM iot_app_test
WHERE n2 <> SYSDATE + 3
N     N1     N2
1     test     4/28/2010 1:59:26.000000 PM
2     test     4/28/2010 1:59:30.000000 PM
3     test     4/28/2010 1:59:33.000000 PM
1     test     4/29/2010 1:59:38.000000 PM
2     test     4/29/2010 1:59:41.000000 PM
3     test     4/29/2010 1:59:44.000000 PM
1     test     4/30/2010 1:59:48.000000 PM
2     test     4/30/2010 1:59:51.000000 PM
3     test     4/30/2010 1:59:53.000000 PM
The query doesn't have an ORDER BY clause, so the results could be in any order. In fact, you can run the exact same query with the exact same data seconds apart, and get a different order every time.
The index doesn't change that. Someone above mentioned an Index Organized Table (which is not merely a table with an index), where you can control the order in which rows are stored (as if you wanted to). There is still no guarantee that, absent an ORDER BY clause, output will be in any particular order.
But when i use the same function in order by clause, its showing the correct result.To repeat what others have said already, the only way to get output in any particular order is to use an ORDER BY clause.
(CONNECT BY queries are the only exception of which I know. There is a partial ordering in CONNECT BY output, even if you don't use ORDER BY or ORDER SUBLINGS BY.)
>
SELECT   *
FROM iot_app_test
ORDER BY SUBSTR (n2, 1, 9) DESC, SUBSTR (n2, 11) ASC;
N     N1     N2
1     test     4/30/2010 1:59:48.000000 PM
2     test     4/30/2010 1:59:51.000000 PM
3     test     4/30/2010 1:59:53.000000 PM
1     test     4/29/2010 1:59:38.000000 PM
2     test     4/29/2010 1:59:41.000000 PM
3     test     4/29/2010 1:59:44.000000 PM
1     test     4/28/2010 1:59:26.000000 PM
2     test     4/28/2010 1:59:30.000000 PM
3     test     4/28/2010 1:59:33.000000 PMCan anyone tell me what's wrong with this.Nothing is wrong.
You're getting the correct output, in the correct order. Why do you think anything is wrong?