ORA-01722 while database upgrade.

SQL> SELECT TO_NUMBER('LABEL_SECURITY_OPTION_OFF') FROM v$option

  2  WHERE value = 'FALSE' and parameter =

  3        (SELECT 'Oracle Label Security' FROM user$ where name = 'DVSYS');

SELECT TO_NUMBER('LABEL_SECURITY_OPTION_OFF') FROM v$option

                 *

ERROR at line 1:

ORA-01722: invalid number

I found the following on MOS: Upgrade Fails With ORA-01722 When Upgrading A Database With Data Vault (Doc ID 1147895.1)

Fix: Install Oracle Label Security (which should enable OLS by default), link Data Vault off with the dv_off target (if not already done), and then peform the upgrade. Data Vault can be linked back on (with the dv_on target) after the upgrade is completed.

I did the following, after which upgrade completed fine

chopt enable lbac

$ chopt enable lbac

Writing to /opt/app/oracle/product/11.2.0.4/install/enable_lbac.log...

/usr/bin/make -f /opt/app/oracle/product/11.2.0.4/rdbms/lib/ins_rdbms.mk lbac_on ORACLE_HOME=/opt/app/oracle/product/11.2.0.4/

/usr/bin/make -f /opt/app/oracle/product/11.2.0.4/rdbms/lib/ins_rdbms.mk ioracle ORACLE_HOME=/opt/app/oracle/product/11.2.0.4/

$ make -f ins_rdbms.mk dv_off

/usr/bin/ar cr /opt/app/oracle/product/11.2.0.4/rdbms/lib/libknlopt.a /opt/app/oracle/product/11.2.0.4/rdbms/lib/kzvndv.o