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

This error is related to DB Time synchronization with Operating system Timestamp. SCN of the database time and Timestamp of the OS should be the same, if not ORA-01466 is thrown.

Example:

Extract SYSTIMESTAMP and SCN

SQL> SELECT SYSTIMESTAMP,DBMS_FLASHBACK.GET_SYSTEM_CHANGE_NUMBER AS scn FROM dual;

SYSTIMESTAMP                                            SCN
————————————————————————— ———-
13-SEP-22 11.19.51.565583 AM +03:00       2763617

SQL>

Convert the SCN number above to TIMESTAMP

SQL> SELECT SCN_TO_TIMESTAMP(2763617) AS ts FROM dual;

TS
—————————————————————————
13-SEP-22 11.19.50.000000000 AM

SQL>

As you can see in the above query SCN and TIMESTAMP of the system are the same.

And the solution for ORA-01466 error is to configure the OS time and recreate the database software again.