System Change Number (SCN)

How to Resolve ORA-01466: unable to read data - table definition has changed

by Ed Chen
March 16, 2023March 21, 2023

ORA-01466 Tried to perform a flashback query, but it failed with ORA-01466. SQL> select count(*) cnt from t1 as of timestamp to_timestamp('2023-02-19 22:15:00', 'yyyy-mm-dd hh24:mi:ss');… Read More »

How to Resolve ORA-01152: file 1 was not restored from a sufficiently old backup

by Ed Chen
March 18, 2020December 12, 2022
4 Comments

When I tried to open the standby database to READ ONLY for later real-time query of Active Data Guard (ADG), I got this error message.… Read More »

How to Map Timestamp to SCN or Vice Versa

by Ed Chen
October 24, 2012February 20, 2023

If you are trying to do an incomplete recovery (also called Point-In-Time Recovery, PITR), you may want to know a System Change Number (SCN) using… Read More »

How to Check Current System Change Number (SCN)

by Ed Chen
October 23, 2012February 8, 2023

System Change Number Some DBAs will schedule a cron job to capture System Change Number (SCN) periodically to save as a Timestamp/SCN mapping reference. To… Read More »