[20171107]dbms_shared_pool.pin补充.txt

[20171107]dbms_shared_pool.pin补充.txt

--//上午的测试,做一些补充,主要还是一些理解问题.

1.环境:
SCOTT@book> @ &r/ver1

PORT_STRING                    VERSION        BANNER
------------------------------ -------------- --------------------------------------------------------------------------------
x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production

SCOTT@book> create sequence seq2 order;
Sequence created.

SCOTT@book> select * from dba_sequences where sequence_name = 'SEQ2' and sequence_owner=user;
SEQUENCE_OWNER                 SEQUENCE_NAME                   MIN_VALUE  MAX_VALUE INCREMENT_BY C O CACHE_SIZE LAST_NUMBER
------------------------------ ------------------------------ ---------- ---------- ------------ - - ---------- -----------
SCOTT                          SEQ2                                    1 1.0000E+28            1 N Y         20           1

2.测试:
--//session 1:
SCOTT@book> select seq2.nextval from dual;

   NEXTVAL
----------
       142

--//注:执行许多次了.
--//session 2:
SELECT KGLHDADR, KGLHDPAR, KGLHDCLT, KGLNAOWN, KGLNAOBJ, KGLFNOBJ
  FROM x$kglob a
WHERE kglobtyd = 'SEQUENCE'
   AND kglnaobj = 'SEQ2';

KGLHDADR         KGLHDPAR           KGLHDCLT KGLNAOWN KGLNAOBJ                       KGLFNOBJ
---------------- ---------------- ---------- -------- ------------------------------ --------------------
000000007BBBCFF0 000000007BBBCFF0     119696 SCOTT    SEQ2                           SEQ2

SYS@book> @ &r/sharepool/shp4 000000007BBBCFF0 0
old  18:  WHERE kglobt03 = '&1'  or kglhdpar='&1' or kglhdadr='&1' or KGLNAHSH= &2
new  18:  WHERE kglobt03 = '000000007BBBCFF0'  or kglhdpar='000000007BBBCFF0' or kglhdadr='000000007BBBCFF0' or KGLNAHSH= 0
TEXT           KGLHDADR         KGLHDPAR         C40  KGLHDIVC KGLOBHD0         KGLOBHD6           KGLOBHS0   KGLOBHS6   KGLOBT16   N0_6_16        N20   KGLNAHSH KGLOBT03        KGLOBT09
-------------- ---------------- ---------------- ---- -------- ---------------- ---------------- ---------- ---------- ---------- --------- ---------- ---------- ------------- ----------
父游标句柄地址 000000007BBBCFF0 000000007BBBCFF0 SEQ2        0 000000007BBBCB08 00                     4728          0          0      4728       4728 3497251728                       10

SYS@book> alter system flush shared_pool;
System altered.

SYS@book> @ &r/sharepool/shp4 000000007BBBCFF0 0
old  18:  WHERE kglobt03 = '&1'  or kglhdpar='&1' or kglhdadr='&1' or KGLNAHSH= &2
new  18:  WHERE kglobt03 = '000000007BBBCFF0'  or kglhdpar='000000007BBBCFF0' or kglhdadr='000000007BBBCFF0' or KGLNAHSH= 0
TEXT           KGLHDADR         KGLHDPAR         C40  KGLHDIVC KGLOBHD0         KGLOBHD6           KGLOBHS0   KGLOBHS6   KGLOBT16   N0_6_16        N20   KGLNAHSH KGLOBT03        KGLOBT09
-------------- ---------------- ---------------- ---- -------- ---------------- ---------------- ---------- ---------- ---------- --------- ---------- ---------- ------------- ----------
父游标句柄地址 000000007BBBCFF0 000000007BBBCFF0 SEQ2        0 00               00                        0          0          0         0          0 3497251728                        0

--//快下班在这里转不出来,为什么还在共享池中,仅仅堆0信息被清除了.下午才想起来,如果会话不退出,无论如何刷新,都存在的.
--//session 1 ,现在退出.

SYS@book> @ &r/sharepool/shp4 000000007BBBCFF0 0
old  18:  WHERE kglobt03 = '&1'  or kglhdpar='&1' or kglhdadr='&1' or KGLNAHSH= &2
new  18:  WHERE kglobt03 = '000000007BBBCFF0'  or kglhdpar='000000007BBBCFF0' or kglhdadr='000000007BBBCFF0' or KGLNAHSH= 0
TEXT           KGLHDADR         KGLHDPAR         C40    KGLHDIVC KGLOBHD0         KGLOBHD6           KGLOBHS0   KGLOBHS6   KGLOBT16   N0_6_16        N20   KGLNAHSH KGLOBT03        KGLOBT09
-------------- ---------------- ---------------- ---- ---------- ---------------- ---------------- ---------- ---------- ---------- --------- ---------- ---------- ------------- ----------
父游标句柄地址 000000007BBBCFF0 000000007BBBCFF0 SEQ2          0 00               00                        0          0          0         0          0 3497251728                        0

SYS@book> alter system flush shared_pool;
System altered.

SYS@book> @ &r/sharepool/shp4 000000007BBBCFF0 0
old  18:  WHERE kglobt03 = '&1'  or kglhdpar='&1' or kglhdadr='&1' or KGLNAHSH= &2
new  18:  WHERE kglobt03 = '000000007BBBCFF0'  or kglhdpar='000000007BBBCFF0' or kglhdadr='000000007BBBCFF0' or KGLNAHSH= 0
no rows selected

--//可以发现现在已经不再共享池了,自己有点蒙....^_^.

3.再看看keep的情况.

--//session 1:
SCOTT@book> select seq2.nextval from dual;
   NEXTVAL
----------
       162

--//session 2:
SYS@book> exec dbms_shared_pool.keep('SCOTT.SEQ2','Q');
PL/SQL procedure successfully completed.

SELECT KGLHDADR, KGLHDPAR, KGLHDCLT, KGLNAOWN, KGLNAOBJ, KGLFNOBJ ,KGLHDKMK
  FROM x$kglob a
WHERE kglobtyd = 'SEQUENCE'
   AND kglnaobj = 'SEQ2';

KGLHDADR         KGLHDPAR           KGLHDCLT KGLNAOWN KGLNAOBJ KGLFNOBJ               KGLHDKMK
---------------- ---------------- ---------- -------- -------- -------------------- ----------
000000007D2CD020 000000007D2CD020     119696 SCOTT    SEQ2     SEQ2                          1

SYS@book> @ &r/sharepool/shp4 000000007D2CD020 0
old  18:  WHERE kglobt03 = '&1'  or kglhdpar='&1' or kglhdadr='&1' or KGLNAHSH= &2
new  18:  WHERE kglobt03 = '000000007D2CD020'  or kglhdpar='000000007D2CD020' or kglhdadr='000000007D2CD020' or KGLNAHSH= 0
TEXT           KGLHDADR         KGLHDPAR         C40   KGLHDIVC KGLOBHD0         KGLOBHD6           KGLOBHS0   KGLOBHS6   KGLOBT16   N0_6_16        N20   KGLNAHSH KGLOBT03        KGLOBT09
-------------- ---------------- ---------------- ----- -------- ---------------- ---------------- ---------- ---------- ---------- --------- ---------- ---------- ------------- ----------
父游标句柄地址 000000007D2CD020 000000007D2CD020 SEQ2         0 000000007D2CCB38 00                     4728          0          0      4728       4728 3497251728                       10

SYS@book> alter system flush shared_pool;
System altered.

SYS@book> alter system flush shared_pool;
System altered.

SYS@book> @ &r/sharepool/shp4 000000007D2CD020 0
old  18:  WHERE kglobt03 = '&1'  or kglhdpar='&1' or kglhdadr='&1' or KGLNAHSH= &2
new  18:  WHERE kglobt03 = '000000007D2CD020'  or kglhdpar='000000007D2CD020' or kglhdadr='000000007D2CD020' or KGLNAHSH= 0
TEXT           KGLHDADR         KGLHDPAR         C40  KGLHDIVC KGLOBHD0         KGLOBHD6           KGLOBHS0   KGLOBHS6   KGLOBT16   N0_6_16        N20   KGLNAHSH KGLOBT03        KGLOBT09
-------------- ---------------- ---------------- ---- -------- ---------------- ---------------- ---------- ---------- ---------- --------- ---------- ---------- ------------- ----------
父游标句柄地址 000000007D2CD020 000000007D2CD020 SEQ2        0 000000007D2CCB38 00                     4728          0          0      4728       4728 3497251728                       10

--//即使session 1退出,这个seq2也会保持在共享池中.
SYS@book> alter system flush shared_pool;
System altered.

SYS@book> @ &r/sharepool/shp4 000000007D2CD020 0
old  18:  WHERE kglobt03 = '&1'  or kglhdpar='&1' or kglhdadr='&1' or KGLNAHSH= &2
new  18:  WHERE kglobt03 = '000000007D2CD020'  or kglhdpar='000000007D2CD020' or kglhdadr='000000007D2CD020' or KGLNAHSH= 0
TEXT           KGLHDADR         KGLHDPAR         C40  KGLHDIVC KGLOBHD0         KGLOBHD6           KGLOBHS0   KGLOBHS6   KGLOBT16   N0_6_16        N20   KGLNAHSH KGLOBT03        KGLOBT09
-------------- ---------------- ---------------- ---- -------- ---------------- ---------------- ---------- ---------- ---------- --------- ---------- ---------- ------------- ----------
父游标句柄地址 000000007D2CD020 000000007D2CD020 SEQ2        0 000000007D2CCB38 00                     4728          0          0      4728       4728 3497251728                       10

--//这让想起vage书中讲解,刷新一定要一组相似的程序不再运行,刷新才能剔除许多组件.

4.取消keep.
SYS@book> exec dbms_shared_pool.unkeep('SCOTT.SEQ2','Q');
PL/SQL procedure successfully completed.

SYS@book> alter system flush shared_pool;
System altered.

SYS@book> @ &r/sharepool/shp4 000000007D2CD020 0
old  18:  WHERE kglobt03 = '&1'  or kglhdpar='&1' or kglhdadr='&1' or KGLNAHSH= &2
new  18:  WHERE kglobt03 = '000000007D2CD020'  or kglhdpar='000000007D2CD020' or kglhdadr='000000007D2CD020' or KGLNAHSH= 0
no rows selected

SELECT KGLHDADR, KGLHDPAR, KGLHDCLT, KGLNAOWN, KGLNAOBJ, KGLFNOBJ ,KGLHDKMK
  FROM x$kglob a
WHERE kglobtyd = 'SEQUENCE'
  AND kglnaobj = 'SEQ2';
no rows selected

--//顺便测试,这样是否可以keep.

SYS@book> exec dbms_shared_pool.keep('SCOTT.SEQ2','Q');
PL/SQL procedure successfully completed.

SELECT KGLHDADR, KGLHDPAR, KGLHDCLT, KGLNAOWN, KGLNAOBJ, KGLFNOBJ ,KGLHDKMK
  FROM x$kglob a
WHERE kglobtyd = 'SEQUENCE'
   AND kglnaobj = 'SEQ2';

KGLHDADR         KGLHDPAR           KGLHDCLT KGLNAOWN KGLNAOBJ KGLFNOBJ KGLHDKMK
---------------- ---------------- ---------- -------- -------- -------- --------
000000007DBFCD50 000000007DBFCD50     119696 SCOTT    SEQ2     SEQ2            1

SYS@book> @ &r/sharepool/shp4 000000007DBFCD50 0
old  18:  WHERE kglobt03 = '&1'  or kglhdpar='&1' or kglhdadr='&1' or KGLNAHSH= &2
new  18:  WHERE kglobt03 = '000000007DBFCD50'  or kglhdpar='000000007DBFCD50' or kglhdadr='000000007DBFCD50' or KGLNAHSH= 0
TEXT           KGLHDADR         KGLHDPAR         C40   KGLHDIVC KGLOBHD0         KGLOBHD6           KGLOBHS0   KGLOBHS6   KGLOBT16   N0_6_16        N20   KGLNAHSH KGLOBT03 KGLOBT09
-------------- ---------------- ---------------- ----- -------- ---------------- ---------------- ---------- ---------- ---------- --------- ---------- ---------- -------- --------
父游标句柄地址 000000007DBFCD50 000000007DBFCD50 SEQ2         0 000000007CFE7010 00                     4728          0          0      4728       4728 3497251728                10

--//另外还有一个不理解的地方,KGLOBT09=10表示什么?在sql语句中这个表示child_number.