System Tables Views Oracle PLSQL

SQL>
SQL> create table emp(
  2           emp_id                integer         primary key
  3          ,lastname               varchar2(20)    not null
  4          ,firstname              varchar2(15)    not null
  5          ,midinit                varchar2(1)
  6          ,street                 varchar2(30)
  7          ,city                   varchar2(20)
  8          ,state                  varchar2(2)
  9          ,zip                    varchar2(5)
 10          ,shortZipCode                   varchar2(4)
 11          ,area_code              varchar2(3)
 12          ,phone                  varchar2(8)
 13          ,company_name           varchar2(50));
Table created.
SQL>
SQL>
SQL> create index emp_2_idx_phone on emp (phone);
Index created.
SQL>
SQL> select index_name, table_name, uniqueness
  2    from user_indexes
  3   where index_name = 'EMP_2_IDX_PHONE';
SQL>
SQL> drop table emp;
Table dropped.
SQL>