How to find list of rows being affected in an update?

Question

Yesterday I made a data correction in my Oracle table in production environment. But later I found out that however my selection command fetched 62 rows, apparently with the same conditions 64 rows got updated. Since I do not have the list of rows affected in that update, I am unable to compare the list of rows selected and later the list of rows updated. So is there a way to find the list of rows that were updated on that particular time on that table, say from 16:20 to 16:21? Does Oracle keep track on which time which rows of a given table were updated?

Answer 1

If you have flashback enabled on your database you can check the data at a particular time in the database.

SELECT * FROM table
AS OF TIMESTAMP 
TO_TIMESTAMP('2015-01-14 13:33:00', 'YYYY-MM-DD HH:MI:SS')
WHERE column = 'your value';

Using this you can check the data before and after for the records you suspect. If you cant find the records, then you can use

SELECT SCN_TO_TIMESTAMP(ORA_ROWSCN) FROM table where <<your condition>>

However SCN_TO_TIMESTAMP(ORA_ROWSCN) can be obtained only for few records which were updated recently. You can only convert to and from SCNs that are in the redo/flashback window maintained by the system. Once changes age out then the mapping is lost.

Answer 2

Try and use oracle FLASHBACK functionality (just in case your database is configured as per flashback utility)

if enabled, it will show you your table's data at any given point of time in past.

for more details on this, please follow http://docs.oracle.com/cd/E11882_01/appdev.112/e41502/adfns_flashback.htm#ADFNS01001