[20200211]使用DBMS_SHARED_POOL.MARKHOT與sql_id的計算.txt

lfree發表於2020-02-11
SQL

[20200211]使用DBMS_SHARED_POOL.MARKHOT與sql_id的計算.txt

--//以前寫的，使用DBMS_SHARED_POOL.MARKHOT標記熱的sql_id,這樣相同的sql語句使用不同的sql_id.
--//連結：http://blog.itpub.net/267265/viewspace-2147197/ => [20171110]sql語句相同sql_id可以不同嗎.
--//好奇心想知道,oracle這種情況下如何計算的sql_id的。

--//更正：sql語句使用使用DBMS_SHARED_POOL.MARKHOT標記熱的sql_id時，full_hash_value和sql_id的計算,就是在原來sql語句的基礎
--//上加上 . mod(sid,cpu_count/2)+1數字的字串。
--//如果設定隱含引數_kgl_hot_object_copies，變為加上 . mod(sid,_kgl_hot_object_copies)+1數字的字串。

1.環境:
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> select * from dept where deptno=10;
    DEPTNO DNAME          LOC
---------- -------------- -------------
        10 ACCOUNTING     NEW YORK
--//sql_id='4xamnunv51w9j',可以執行多次,避免sql語句退出共享池.

SELECT name
      ,hash_value
      ,full_hash_value
      ,namespace
      ,child_latch
      ,property hot_flag
      ,executions
      ,invalidations
  FROM v$db_object_cache
 WHERE name = 'select * from dept where deptno=10';

NAME                                     HASH_VALUE FULL_HASH_VALUE                  NAMESPACE  CHILD_LATCH HOT_FLAG   EXECUTIONS INVALIDATIONS
---------------------------------------- ---------- -------------------------------- ---------- ----------- ---------- ---------- -------------
select * from dept where deptno=10        911274289 1431c45dbddbb9e74eaa74d53650f131 SQL AREA             0                     8             0
select * from dept where deptno=10        911274289 1431c45dbddbb9e74eaa74d53650f131 SQL AREA         61745                     8             0
--//確定FULL_HASH_VALUE='1431c45dbddbb9e74eaa74d53650f131'.

$ echo -e -n  'select * from dept where deptno=10\0' | md5sum | sed 's/  -//' | xxd -r -p | od -t x4 | sed  -n  -e 's/^0000000 //' -e 's/ //gp'
1431c45dbddbb9e74eaa74d53650f131
--//對比完全能對上。

2.建立gdb指令碼:
--//參考連結：http://blog.itpub.net/267265/viewspace-2665902/=>[20191127]表 full Hash Value的計算.txt
$ cat md5.gdb
set pagination off

break kggmd5Update
  commands
    printf "Length: %d\n",$rdx
    x/40xc $rsi
    c
  end

break kglComputeHash
  commands
    c
  end

break kggmd5Process
  commands
    c
  end

break kggmd5Finish
  commands
    c
  end

3.測試分析:
--//首先使用DBMS_SHARED_POOL.MARKHOT標記。
SYS@book> exec dbms_shared_pool.markhot( hash=>'1431c45dbddbb9e74eaa74d53650f131', namespace=>0, global=>true);
PL/SQL procedure successfully completed.

--//以scott登入
--//session 1:
SCOTT@book> @ spid
       SID    SERIAL# PROCESS                  SERVER    SPID       PID  P_SERIAL# C50
---------- ---------- ------------------------ --------- ------ ------- ---------- --------------------------------------------------
        58         49 54621                    DEDICATED 54622       28         23 alter system kill session '58,49' immediate;
--//spid=54622
--//session 2:
$ gdb -p 54622 -x md5.gdb

--//session 1:
--//測試前可以先執行Select * from dept where deptno=10;注意S大寫sql語句與原來不同。
Select * from dept where deptno=10

SCOTT@book> select * from dept where deptno=10;
    DEPTNO DNAME          LOC
---------- -------------- -------------
        10 ACCOUNTING     NEW YORK

@ dpc '' ''
--//輸出略，查詢sql_id='7sqgfqarnwk8h',與原來的完成不同。
        
4.觀察gdb的輸出:

--//session 3:
SYS@book> select sql_id,sql_text,executions,length(sql_text),ora_hash(sql_text) from v$sqlarea where sql_text = 'select * from dept where deptno=10' ;
SQL_ID        SQL_TEXT                            EXECUTIONS LENGTH(SQL_TEXT) ORA_HASH(SQL_TEXT)
------------- ----------------------------------- ---------- ---------------- ------------------
7sqgfqarnwk8h select * from dept where deptno=10           3               34          156172166
4xamnunv51w9j select * from dept where deptno=10           8               34          156172166
--//sql_id=7sqgfqarnwk8h.

SELECT name
      ,hash_value
      ,full_hash_value
      ,namespace
      ,child_latch
      ,property hot_flag
      ,executions
      ,invalidations
  FROM v$db_object_cache
 WHERE name = 'select * from dept where deptno=10';

NAME                                     HASH_VALUE FULL_HASH_VALUE                  NAMESPACE  CHILD_LATCH HOT_FLAG   EXECUTIONS INVALIDATIONS
---------------------------------------- ---------- -------------------------------- ---------- ----------- ---------- ---------- -------------
select * from dept where deptno=10       2941143312 5196d0b7fe72e5ea7c59eeb2af4e4910 SQL AREA             0 HOTCOPY11           3             0
select * from dept where deptno=10       2941143312 5196d0b7fe72e5ea7c59eeb2af4e4910 SQL AREA         18704 HOTCOPY11           3             0
select * from dept where deptno=10        911274289 1431c45dbddbb9e74eaa74d53650f131 SQL AREA             0 HOT                 8             0
select * from dept where deptno=10        911274289 1431c45dbddbb9e74eaa74d53650f131 SQL AREA         61745 HOT                 8             0
--//可以發現新建立的sql語句FULL_HASH_VALUE=5196d0b7fe72e5ea7c59eeb2af4e4910,注意後面的HOT_FLAG='HOTCOPY11'.
--//0x4910  = 18704

--//session 2:
(gdb) c
Continuing.

Breakpoint 1, 0x00000000097f09a8 in kggmd5Update ()
Length: 35
0x7fffff1de9d8: 115 's' 101 'e' 108 'l' 101 'e' 99 'c'  116 't' 32 ' '  42 '*'
0x7fffff1de9e0: 32 ' '  102 'f' 114 'r' 111 'o' 109 'm' 32 ' '  100 'd' 101 'e'
0x7fffff1de9e8: 112 'p' 116 't' 32 ' '  119 'w' 104 'h' 101 'e' 114 'r' 101 'e'
0x7fffff1de9f0: 32 ' '  100 'd' 101 'e' 112 'p' 116 't' 110 'n' 111 'o' 61 '='
0x7fffff1de9f8: 49 '1'  48 '0'  0 '\000'        -13 '? 108 'l' 92 '\\' 107 'k' -64 '?
--//拼接起來就是 select * from dept where deptno=10\0;

Breakpoint 4, 0x00000000097f0830 in kggmd5Finish ()

Breakpoint 1, 0x00000000097f09a8 in kggmd5Update ()
Length: 21
0xbefbe20 <kggmd5padding.0>:    -128 '\200'     0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'
0xbefbe28 <kggmd5padding.0+8>:  0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'
0xbefbe30 <kggmd5padding.0+16>: 0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'
0xbefbe38 <kggmd5padding.0+24>: 0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'
0xbefbe40 <kggmd5padding.0+32>: 0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'

Breakpoint 1, 0x00000000097f09a8 in kggmd5Update ()
Length: 8
0x7fffff1dc910: 24 '\030'       1 '\001'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'
0x7fffff1dc918: -40 '? -23 '? 29 '\035'       -1 ''  -1 ''  127 '\177'      0 '\000'        0 '\000'
0x7fffff1dc920: 32 ' '  -51 '? 29 '\035'       -1 ''  -1 ''  127 '\177'      0 '\000'        0 '\000'
0x7fffff1dc928: -40 '? -23 '? 29 '\035'       -1 ''  -1 ''  127 '\177'      0 '\000'        0 '\000'
0x7fffff1dc930: -64 '? -55 '? 29 '\035'       -1 ''  -1 ''  127 '\177'      0 '\000'        0 '\000'

Breakpoint 2, 0x000000000984457c in kglComputeHash ()

Breakpoint 1, 0x00000000097f09a8 in kggmd5Update ()
Length: 35
0x7fffff1de9d8: 115 's' 101 'e' 108 'l' 101 'e' 99 'c'  116 't' 32 ' '  42 '*'
0x7fffff1de9e0: 32 ' '  102 'f' 114 'r' 111 'o' 109 'm' 32 ' '  100 'd' 101 'e'
0x7fffff1de9e8: 112 'p' 116 't' 32 ' '  119 'w' 104 'h' 101 'e' 114 'r' 101 'e'
0x7fffff1de9f0: 32 ' '  100 'd' 101 'e' 112 'p' 116 't' 110 'n' 111 'o' 61 '='
0x7fffff1de9f8: 49 '1'  48 '0'  0 '\000'        -13 '? 108 'l' 92 '\\' 107 'k' -64 '?
--//拼接起來就是 select * from dept where deptno=10\0;

Breakpoint 1, 0x00000000097f09a8 in kggmd5Update ()
Length: 1
0x9e79fec <_2__STRING.98.0>:    46 '.'  0 '\000'        0 '\000'        0 '\000'        107 'k' 116 't' 99 'c'  110 'n'
0x9e79ff4 <_2__STRING.377.0+4>: 46 '.'  99 'c'  64 '@'  49 '1'  50 '2'  54 '6'  49 '1'  55 '7'
0x9e79ffc <_2__STRING.377.0+12>:        0 '\000'        0 '\000'        0 '\000'        0 '\000'        37 '%'  42 '*'  115 's' 102 'f'
0x9e7a004 <_2__STRING.366.0+4>: 108 'l' 103 'g' 115 's' 58 ':'  32 ' '  48 '0'  120 'x' 37 '%'
0x9e7a00c <_2__STRING.366.0+12>:        48 '0'  56 '8'  120 'x' 32 ' '  0 '\000'        0 '\000'        0 '\000'        0 '\000'
--//length=1 對應'.'

Breakpoint 1, 0x00000000097f09a8 in kggmd5Update ()
Length: 2
0x7fffff1dc460: 49 '1'  49 '1'  0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'
0x7fffff1dc468: 0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'
0x7fffff1dc470: -128 '\200'     -57 '? 29 '\035'       -1 ''  -1 ''  127 '\177'      0 '\000'        0 '\000'
0x7fffff1dc478: 49 '1'  41 ')'  -125 '\203'     9 '\t'  0 '\000'        0 '\000'        0 '\000'        0 '\000'
0x7fffff1dc480: -80 '? -55 '? 29 '\035'       -1 ''  -1 ''  127 '\177'      0 '\000'        0 '\000'
--//注意看這裡,Length: 2，字元正好是'11'.

Breakpoint 4, 0x00000000097f0830 in kggmd5Finish ()

Breakpoint 1, 0x00000000097f09a8 in kggmd5Update ()
Length: 18
0xbefbe20 <kggmd5padding.0>:    -128 '\200'     0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'
0xbefbe28 <kggmd5padding.0+8>:  0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'
0xbefbe30 <kggmd5padding.0+16>: 0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'
0xbefbe38 <kggmd5padding.0+24>: 0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'
0xbefbe40 <kggmd5padding.0+32>: 0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'

Breakpoint 1, 0x00000000097f09a8 in kggmd5Update ()
Length: 8
0x7fffff1dc2a0: 48 '0'  1 '\001'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'
0x7fffff1dc2a8: 0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'
0x7fffff1dc2b0: 32 ' '  -53 '? 29 '\035'       -1 ''  -1 ''  127 '\177'      0 '\000'        0 '\000'
0x7fffff1dc2b8: 0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'        0 '\000'
0x7fffff1dc2c0: 96 '`'  -61 '? 29 '\035'       -1 ''  -1 ''  127 '\177'      0 '\000'        0 '\000'


$ echo -e -n  'select * from dept where deptno=10\0.11' | md5sum | sed 's/  -//' | xxd -r -p | od -t x4 | sed  -n  -e 's/^0000000 //' -e 's/ //gp'
5196d0b7fe72e5ea7c59eeb2af4e4910
--//^_^，正好對上。

SELECT name
      ,hash_value
      ,full_hash_value
      ,namespace
      ,child_latch
      ,property hot_flag
      ,executions
      ,invalidations
  FROM v$db_object_cache
 WHERE name = 'select * from dept where deptno=10';

NAME                                     HASH_VALUE FULL_HASH_VALUE                  NAMESPACE  CHILD_LATCH HOT_FLAG   EXECUTIONS INVALIDATIONS
---------------------------------------- ---------- -------------------------------- ---------- ----------- ---------- ---------- -------------
select * from dept where deptno=10       2941143312 5196d0b7fe72e5ea7c59eeb2af4e4910 SQL AREA             0 HOTCOPY11           3             0
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
select * from dept where deptno=10       2941143312 5196d0b7fe72e5ea7c59eeb2af4e4910 SQL AREA         18704 HOTCOPY11           3             0
select * from dept where deptno=10        911274289 1431c45dbddbb9e74eaa74d53650f131 SQL AREA             0 HOT                 8             0
select * from dept where deptno=10        911274289 1431c45dbddbb9e74eaa74d53650f131 SQL AREA         61745 HOT                 8             0

--//也就是語句生成FULL_HASH_VALUE計算是原來sql語句(注意oracle會做一些格式化操作),後面加上\0  . v$db_object_cache.HOT_FLAG欄位後面的數字。
--//講的再通俗一點就是在原來基礎上加入 . v$db_object_cache.HOT_FLAG欄位後面的數字。

--//使用我寫的指令碼測試（注意要安裝zsh)：
$ ./sql_id.zsh 'select * from dept where deptno=10\0.11'
sql_text = select * from dept where deptno=10.11
full_hash_value(16) = 5196D0B7FE72E5EA7C59EEB2AF4E4910
hash_value(10) = 2941143312
sql_id(32) = 7sqgfqarnwk8h
sql_id(32) = 7sqgfqarnwk8h
--//sql_id=7sqgfqarnwk8h，也與前面查詢v$sqlarea檢視的結果一致。

4.繼續探究，至於後面為什麼加入11，估計與會話sid之類有關(猜測)。
--//退出gbd程式，繼續分析。
--//首先我嘗試退出再登入，我的測試環境sid會保持不變，serial#會發生變化。我執行select * from dept where deptno=10，查詢
--//v$db_object_cache並沒有生成新的sql_id.

SCOTT@book> @ spid
       SID    SERIAL# PROCESS                  SERVER    SPID       PID  P_SERIAL# C50
---------- ---------- ------------------------ --------- ------ ------- ---------- --------------------------------------------------
        58         49 54621                    DEDICATED 54622       28         23 alter system kill session '58,49' immediate;

SCOTT@book> show parameter cpu_count
NAME      TYPE    VALUE
--------- ------- -----
cpu_count integer 24

SCOTT@book> select mod(58,24),mod(58,16) from dual ;
MOD(58,24) MOD(58,16)
---------- ----------
        10         10
--//是否就是這個sid與某個引數取模 10+1，因為沒有見過HOT_FLAG='HOTCOPY0'的情況.至少我沒有見過。
--//建立新的會話:
--//session 4:
SCOTT@book> @ spid
       SID    SERIAL# PROCESS                  SERVER    SPID       PID  P_SERIAL# C50
---------- ---------- ------------------------ --------- ------ ------- ---------- --------------------------------------------------
        30        115 55199                    DEDICATED 55200       26         44 alter system kill session '30,115' immediate;

SCOTT@book> select mod(30,24),mod(30,16) from dual ;
MOD(30,24) MOD(30,16)
---------- ----------
         6         14

SCOTT@book> select * from dept where deptno=10;
    DEPTNO DNAME          LOC
---------- -------------- -------------
        10 ACCOUNTING     NEW YORK

--//session 3:
SELECT name
      ,hash_value
      ,full_hash_value
      ,namespace
      ,child_latch
      ,property hot_flag
      ,executions
      ,invalidations
  FROM v$db_object_cache
 WHERE name = 'select * from dept where deptno=10';

SYS@book> /
NAME                                     HASH_VALUE FULL_HASH_VALUE                  NAMESPACE  CHILD_LATCH HOT_FLAG   EXECUTIONS INVALIDATIONS
---------------------------------------- ---------- -------------------------------- ---------- ----------- ---------- ---------- -------------
select * from dept where deptno=10       2941143312 5196d0b7fe72e5ea7c59eeb2af4e4910 SQL AREA             0 HOTCOPY11           3             0
select * from dept where deptno=10       2941143312 5196d0b7fe72e5ea7c59eeb2af4e4910 SQL AREA         18704 HOTCOPY11           3             0
select * from dept where deptno=10        911274289 1431c45dbddbb9e74eaa74d53650f131 SQL AREA             0 HOT                 8             0
select * from dept where deptno=10        911274289 1431c45dbddbb9e74eaa74d53650f131 SQL AREA         61745 HOT                 8             0
select * from dept where deptno=10       3106222595 642c74f9bf38538acec7e363b9253203 SQL AREA             0 HOTCOPY7            1             0
select * from dept where deptno=10       3106222595 642c74f9bf38538acec7e363b9253203 SQL AREA         78339 HOTCOPY7            1             0
6 rows selected.
--//生成新的HOT_FLAG=HOTCOPY7.正好等於是mod(sid,cpu_count)+1.

SYS@book> select sql_id,sql_text,executions,length(sql_text),ora_hash(sql_text) from v$sqlarea where sql_text = 'select * from dept where deptno=10' ;
SQL_ID        SQL_TEXT                                                     EXECUTIONS LENGTH(SQL_TEXT) ORA_HASH(SQL_TEXT)
------------- ------------------------------------------------------------ ---------- ---------------- ------------------
7sqgfqarnwk8h select * from dept where deptno=10                                    3               34          156172166
4xamnunv51w9j select * from dept where deptno=10                                    8               34          156172166
cxjz3cfwkach3 select * from dept where deptno=10                                    1               34          156172166
~~~~~~~~~~~~~
--//sql_id=cxjz3cfwkach3,HOT_FLAG='HOTCOPY7'

$ echo -e -n  'select * from dept where deptno=10\0.7' | md5sum | sed 's/  -//' | xxd -r -p | od -t x4 | sed  -n  -e 's/^0000000 //' -e 's/ //gp'
642c74f9bf38538acec7e363b9253203

$ ./sql_id.zsh 'select * from dept where deptno=10\0.7'
v1=642C74F9BF38538ACEC7E363B9253203 v2=CEC7E363B9253203 v3=3106222595
sql_text = select * from dept where deptno=10.7
full_hash_value(16) = 642C74F9BF38538ACEC7E363B9253203
hash_value(10) = 3106222595
./sql_id.zsh:1: number truncated after 15 digits: CEC7E363B9253203
sql_id(32) = 0tv3y6sxt4nt0
sql_id(32) =  tv3y6sxt4nt0
--//指令碼有錯，先放一放.好像是V2變數裡面第1個字元C不是數字，我記憶裡好像是我使用伺服器這個zsh版本的bug，晚上在家裡測試看看。
--//使用另外的sql_id.sh指令碼測試：

$ ./sql_id.sh 'select * from dept where deptno=10\0.7'
v1=642C74F9BF38538ACEC7E363B9253203 v2=CEC7E363B9253203 v3=B9253203
sql_text = select * from dept where deptno=10\0.7
full_hash_value(16) = 642C74F9BF38538ACEC7E363B9253203
hash_value(10) = 3106222595
sql_id(32) = cxjz3cfwkach3
sql_id(32) = cxjz3cfwkach3
sql_id(32) = cxjz3cfwkach3
--//正好對上。大家可以再開啟新的會話測試，可以確定sql語句就是在原來基礎上加入. mod(sid,cpu_count)+1數字的字串。

總結：
--//上班太安靜，無聊探究這個問題。
--//sql語句使用使用DBMS_SHARED_POOL.MARKHOT標記熱的sql_id時，full_hash_value和sql_id的計算,就是在原來sql語句的基礎上加上
--// . mod(sid,cpu_count)+1數字的字串。
--//使用DBMS_SHARED_POOL.MARKHOT 標記熱的sql語句，實際上就是使用空間換時間的做法，打散開來。但是我上午的測試可能存在太多爭用
--//反而使用它更慢，有機會測試更多會話的情況。
--//也許因為加入運算的字串採用 . mod(sid,cpu_count)+1數字的字串，也許存在太多的衝突，反而更慢。

--//附上sql_id.sh指令碼，裡面包含幾個從full_hash_value計算sql_id的方法:
$ cat sql_id.sh
#! /bin/bash
# calcucate sql_text of full_hash_value(16),hash_value(10),sql_id(32).
odebug=${ODEBUG:-0}

#sql_text=${1}'\0'
sql_text=${1}
v1=$(echo -e -n "$sql_text" | md5sum | sed 's/  -//' | xxd -r -p | od -t x4 |  sed   -n  -e 's/^0\+ //' -e 's/ //gp' | tr 'a-z' 'A-Z')
v2=${v1:(-16):16}
v3=${v2:(-8):8}
# v2=$(echo "obase=16;ibase=16; $v1 % 10000000000000000" | bc| tr -d '\\\r\n')
# v3=$(echo "obase=10;ibase=16; $v1 % 100000000" | bc| tr -d '\\\r\n')

if [ $odebug -eq 1 ] ; then
        echo v1=$v1 v2=$v2 v3=$v3
fi

echo "sql_text = $sql_text"
echo "full_hash_value(16) = $v1 "
echo "hash_value(10) = $(( 16#$v3 )) "

BASE32=($(echo {0..9} {a..z} | tr -d 'eilo'))
res=''
for i in $(echo "obase=32;ibase=16; $v2" | bc| tr -d '\\\r\n')
do
        res=${res}${BASE32[$(( 10#$i ))]}
done
echo "sql_id(32) = $(printf "%13s" $res | tr ' ' '0')"
echo "sql_id(32) = $(printf "%013s" $res)"

res1=$(eval $(echo "obase=32;ibase=16; $v2" | bc| tr -d '\\\r\n' | awk 'BEGIN{RS=" +"; printf "echo " }/./{printf "${BASE32[$(( 10#%02d))]} ", $1}' ))
res1=$(tr -d " " <<< $res1)
echo "sql_id(32) = $(printf "%013s" $res1)"



來自 “ ITPUB部落格 ” ，連結：http://blog.itpub.net/267265/viewspace-2675128/，如需轉載，請註明出處，否則將追究法律責任。

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