SQL> create table t1 ( x int, y int , z int )
  2  partition by list (x )
  3  ( partition p1 values (1),
  4    partition p2 values (2),
  5    partition p3 values (3)
  6  );

Table created.

SQL>
SQL> insert /*+ APPEND */ into t1
  2  select 1, rownum, rownum
  3  from ( select 1 from dual connect by level <= 1000 ),
  4       ( select 1 from dual connect by level <= 10000 );

10000000 rows created.

SQL>
SQL> commit;

Commit complete.

SQL>
SQL> insert /*+ APPEND */ into t1
  2  select 2, rownum, rownum
  3  from ( select 1 from dual connect by level <= 1000 ),
  4       ( select 1 from dual connect by level <= 10000 );

10000000 rows created.

SQL>
SQL> commit;

Commit complete.

SQL>
SQL> insert /*+ APPEND */ into t1
  2  select 3, rownum, rownum
  3  from ( select 1 from dual connect by level <= 1000 ),
  4       ( select 1 from dual connect by level <= 10000 );

10000000 rows created.

SQL>
SQL> commit;

Commit complete.

SQL>
SQL> create index IX1 on T1 ( y ) ;

Index created.

SQL> create index IX2 on T1 ( z ) ;

Index created.

SQL>
SQL> alter table t1 truncate partition p1 update global indexes parallel 4;
[running]

SQL> select sid, status, username, sql_id from v$session where username = 'SCOTT';

       SID STATUS   USERNAME                                      SQL_ID
---------- -------- --------------------------------------------- -------------
        12 ACTIVE   SCOTT                                         g4w438qx7f5h7
        13 ACTIVE   SCOTT                                         g4w438qx7f5h7
       125 ACTIVE   SCOTT                                         g4w438qx7f5h7
       126 ACTIVE   SCOTT                                         g4w438qx7f5h7
       242 ACTIVE   SCOTT                                         g4w438qx7f5h7
       243 ACTIVE   SCOTT                                         g4w438qx7f5h7
       245 INACTIVE SCOTT                                         g4w438qx7f5h7
       360 ACTIVE   SCOTT                                         g4w438qx7f5h7
       365 INACTIVE SCOTT                                         g4w438qx7f5h7
       
       
SQL> @text g4w438qx7f5h7

CHILD_NUMBER SQL_FULLTEXT
------------ --------------------------------------------------------------------------------
           0 insert /*+ RELATIONAL("T1") PARALLEL("T1",4) APPEND NESTED_TABLE_SET_SETID NO_RE
             F_CASCADE */ into "SCOTT"."T1" partition ("P1") (select /*+ RELATIONAL("T1") P
             ARALLEL("T1",4) */  *  from "SCOTT"."T1" partition ("P1") ) delete global inde
             xes