If you want to rebuild an index, you can use the "ALTER INDEX ... REBUILD statement as shown in the following SQL script:

SELECT index_name, table_name, uniqueness

FROM USER_INDEXES WHERE table_name = 'EMPLOYEES';

INDEX_NAME   TABLE_NAME  UNIQUENES

----------------------- --------------------- ---------

EMP_EMAIL_UK  EMPLOYEES   UNIQUE

EMP_EMP_ID_PK   EMPLOYEES   UNIQUE

EMP_DEPARTMENT_IX  EMPLOYEES   NONUNIQUE

EMP_JOB_IX   EMPLOYEES   NONUNIQUE

EMP_MANAGER_IX  EMPLOYEES   NONUNIQUE

EMP_NAME_IX   EMPLOYEES   NONUNIQUE

ALTER INDEX EMP_NAME_IX REBUILD;

Statement processed.