I am new to oracle. I have developed an application in java which extracts the records from database, user update few fields and update query is run through java application to make the changes in database. This application is working from past 6 months and no issue was encountered.
Yesterday around 8000 records were processed by various users in this way. In evening, i was able to see the updated records using my application .. But today morning, data of only around 1000 records were shown to be updated.. For remaining records(around 7000), value in specific fields are showing null. Yesterday these fields were having some value in around 7000 records...
Can you please help me how should i start troubleshooting this.. How can i find how these records were modified..
If the columns had non-null values yesterday and they're null now, SOMETHING updated them back.
If you're
really lucky, you may be able to spot when the changes happened using flashback query:
select t.*,
versions_xid,
versions_starttime,
versions_endtime
from <your table>
versions between timestamp
sysdate - 1 and sysdate t
where versions_operation = 'U';But chances are this information has aged out of undo by now. So this will error.
Failing this, look at any auditing you've enabled (either Oracle Database auditing or any custom auditing you've created using triggers or whatever).
Failing this, you may be able to use LogMiner to analyze your redo logs to see when the update back happened
https://docs.oracle.com/en/database/oracle/oracle-database/19/sutil/oracle-logminer-utility.html#GUID-3417B738-374C-4EE3-B15C-3A66E01AE2B5 https://oracle-base.com/articles/8i/logminer If none of the above help... start checking your code for updates with missing/wrong where clauses & asking your users to see if you can find the culprit