[root@localhost ~]# su - oracle
[oracle@localhost ~]$ export ORACLE_SID=orcl
[oracle@localhost ~]$ sqlplus

username:system
password: password

SQL>@?/rdbms/admin/utlxplan

SQL>grant all on plan_table to public;

SQL>exit

[oracle@localhost ~]$ export ORACLE_SID=orcl
[oracle@localhost ~]$ sqlplus
username: / as sysdba

SQL>@?/sqlplus/admin/plustrce
SQL>grant plustrace to public;


AUTOTRACE OPTIONS: -

1) SET AUTOTRACE OFF - No AUTOTRACE report is generated.
This is the default. Queries are run as normal.

2) SET AUTOTRACE ON EXPLAIN - The query is run as normal,
and the AUTOTRACE report shows only the optimizer
execution path.

3) SET AUTOTRACE ON STATISTICS - The query is run as normal,
and the AUTOTRACE report shows only the SQL statement
execution statistics.

4) SET AUTOTRACE ON - The query execution takes place,
and the AUTOTRACE report includes both the optimizer
execution path and the SQL statement execution statistics.

5) SET AUTOTRACE TRACEONLY - Like SET AUTOTRACE ON, but
suppresses the printing of the query output, if any.

6) SET AUTOTRACE TRACEONLY STATISTICS - Like SET AUTOTRACE
TRACEONLY,but suppresses the display of the query plan.
It shows only the execution statistics.

7) SET AUTOTRACE TRACEONLY EXPLAIN - Like SET AUTOTACE
TRACEONLY,but suppresses the display of the execution
statistics,showing only the query plan. This setting
does not actually execute the query. It only parses
and explains the query.