question about Parallel Query

 
about Parallel Query

in our system,we find our system there is a lot of ora_p0**_ora11g process to run;
i check it ora_p0**_ora11g is Parallel query processes ，there is 16 cpu in our system,

like 64 Parallel query processes,
oracle    6200     1  0 11:49 ?        00:00:00 ora_p001_ora11g
.........
.........
.........
oracle    6372     1  0 11:49 ?        00:00:00 ora_p061_ora11g
oracle    6454     1  0 11:49 ?        00:00:00 ora_p062_ora11g
oracle    6536     1  0 11:49 ?        00:00:00 ora_p063_ora11g

use this sql check current Parallel query .no current sid row select.
SQL> select pid,sid,sid,SERIAL# from V$PX_PROCESS;

       PID        SID        SID    SERIAL#
---------- ---------- ---------- ----------
        25
        73
        85
        98
        84
        67
        87
        24
.........
.........
.........
        65
        95
        30
       102
        78
        92
        34
        29

64 rows selected.

SQL> show parameters parallel

NAME                                 TYPE        VALUE