SQL Server:RowVersion tilsvarende i Oracle

Oracle har SCN (System Change Numbers):http://docs.oracle.com/cd/E11882_01/server.112/e10713/transact.htm#CNCPT039

Brug en ORA_ROWSCN-pseudokolonne til at undersøge det aktuelle SCN af rækker:
http://docs.oracle.com/cd/B28359_01/server.111/b28286/pseudocolumns007.htm#SQLRF51145

Et eksempel:

SELECT ora_rowscn, t.* From test t;

Demo --> http://www.sqlfiddle.com/#!4/535bc /1
(På SQLFiddle virker eksplicitte commits tilsyneladende ikke - på en rigtig database øger hver commit SCN).

Et eksempel på en "rigtig" database:

CREATE TABLE test(
  id int,
  value int
);

INSERT INTO test VALUES(1,0);
COMMIT;
SELECT ora_rowscn, t.* FROM test t;

ORA_ROWSCN         ID      VALUE
---------- ---------- ----------
   3160728          1          0

UPDATE test SET value = value + 1 WHERE id = 1;
COMMIT;
SELECT ora_rowscn, t.* FROM test t;

ORA_ROWSCN         ID      VALUE
---------- ---------- ----------
   3161657          1          1

UPDATE test SET value = value + 1 WHERE id = 1;
COMMIT;
SELECT ora_rowscn, t.* FROM test t;

ORA_ROWSCN         ID      VALUE
---------- ---------- ----------
   3161695          1          2

Hvis SCN for transaktionen er kendt, kan vi bruge en flashback-forespørgsel til at få en tidligere værdi af rækken:
http://docs.oracle.com/cd/B28359_01/appdev.111/b28424/adfns_flashback.htm#g16131

Et eksempel:

SELECT t.*,
       versions_startscn, versions_starttime,
       versions_endscn, versions_endtime,
       versions_xid, versions_operation
FROM test VERSIONS BETWEEN SCN MINVALUE AND MAXVALUE t;

        ID      VALUE VERSIONS_STARTSCN VERSIONS_STARTTIME  VERSIONS_ENDSCN VERSIONS_ENDTIME    VERSIONS_XID     VERSIONS_OPERATION
---------- ---------- ----------------- ------------------- --------------- ------------------- ---------------- ------------------
         1          2           3161695 13/12/10 08:19:39                                       06000300EA070000 U                  
         1          1           3161657 13/12/10 08:18:39           3161695 13/12/10 08:19:39   06001200EA070000 U                  
         1          0                                               3161657 13/12/10 08:18:39                         


SELECT t.*,
       versions_startscn, versions_starttime,
       versions_endscn, versions_endtime,
       versions_xid, versions_operation
FROM test VERSIONS BETWEEN SCN 3161657 AND 3161657 t;

        ID      VALUE VERSIONS_STARTSCN VERSIONS_STARTTIME  VERSIONS_ENDSCN VERSIONS_ENDTIME    VERSIONS_XID     VERSIONS_OPERATION
---------- ---------- ----------------- ------------------- --------------- ------------------- ---------------- ------------------
         1          1           3161657 13/12/10 08:18:39                                       06001200EA070000 U