The ORA-28009 connection to SYS shocould be as sysdba or sysoper error occurs when the Sys user executes the IMP statement after exporting the DMP file with the Scott user

The Import Statement is imp sys/Sakura file = A. DMP, And the ORA-28009 connection to SYS shocould be as sysdba or sysoper error is returned.

Solution:

(1) set the parameter o7_dictionary_accessibility = true.

This parameter defaults to true before 9i, but is false from 9i. If you do not change this parameter, use connect sys/password @ connectstring directly, and the following error is reported:
ORA-28009: connection to SYS shoshould be as sysdba or sysoper
So when IMP sys/password @ connectstring file =... cannot import data,
After the change, you can use the Sys identity IMP to import the data in the SYS export under 8i.