SQL Plus 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> insert into emp(emp_id,lastname,firstname,midinit,street,city,state,zip,shortZipCode,area_code,phone,company_name)values
  2                      (1,'Jones','Joe','J','1 Ave','New York','NY','11202','1111','212', '221-4333','Big Company');
1 row created.
SQL> insert into emp(emp_id,lastname,firstname,midinit,street,city,state,zip,shortZipCode,area_code,phone,company_name)values
  2                      (2,'Smith','Sue','J','1 Street','New York','NY','11444','1111','212', '436-6773','Little Company');
1 row created.
SQL> insert into emp(emp_id,lastname,firstname,midinit,street,city,state,zip,shortZipCode,area_code,phone,company_name)values
  2                      (3,'X','Peggy','J','1 Drive','New York','NY','45502','2222','212', '234-4444','Medium Company');
1 row created.
SQL> explain plan for
  2  select *
  3  from emp
  4  where lastname = 'Young';
Explained.
SQL> select operation
  2  from plan_table;
SELECT STATEMENT
TABLE ACCESS
SELECT STATEMENT
TABLE ACCESS
SELECT STATEMENT
TABLE ACCESS
6 rows selected.
SQL> explain plan for
  2  select *
  3  from emp
  4  where firstname='Joe';
Explained.
SQL> select operation
  2  from plan_table;
SELECT STATEMENT
TABLE ACCESS
SELECT STATEMENT
TABLE ACCESS
SELECT STATEMENT
TABLE ACCESS
SELECT STATEMENT
TABLE ACCESS
8 rows selected.
SQL>
SQL>
SQL> set autotrace off
SQL>
SQL> drop table emp;
Table dropped.
SQL>
SQL>