Before performing any update activity of the database perform the below steps for creating restrore points by which we can restore the database to the before_update state.
SQL> shutdown immediate;
SQL> startup mount;
SQL> select log_mode,flashback_on from v$database;
If the database in NO ARCHIVE LOG MODE , enable the archive log mode mode
SQL> ALTER DATABASE ARCHIVELOG;
SQL> create restore point BEFORE_SCHEMA_CHANGES guarantee flashback database;
SQL> alter database open;
SQL> /*If an error occurs during update process*/
SQL> shutdown immediate;
SQL> startup mount;
SQL> flashback database to restore point BEFORE_SCHEMA_CHANGES;
SQL> alter database open resetlogs;
QL> select flashback_on from v$database;
FLASHBACK_ON
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RESTORE POINT ONLY