分类目录归档：Oracle

lob类型数据转换为系统文件

发表于 2012 年 3 月 21 日 由 惜分飞

1.插入一条blob数据

SQL> create directory ULTLOBDIR as '/home/oracle';

Directory created.

SQL> create table blobtest(col1 BLOB);

Table created.

SQL> declare
a_blob BLOB;
  2    3  bfile_name BFILE := BFILENAME('ULTLOBDIR','tt.txt.bak');
  4  begin
  5  insert into blobtest values (empty_blob())
  6  returning col1 into a_blob;
  7  dbms_lob.fileopen(bfile_name);
  8  dbms_lob.loadfromfile(a_blob, bfile_name, dbms_lob.getlength(bfile_name));
  9  dbms_lob.fileclose(bfile_name);
 10  commit;
 11  end;
 12  /

PL/SQL procedure successfully completed.

SQL> select dbms_lob.getlength(col1) from blobtest;

DBMS_LOB.GETLENGTH(COL1)
------------------------
                    4829

SQL> !pwd
/home/oracle

SQL> !ls -l tt.txt.bak
-rw-r--r-- 1 oracle oinstall 4829 03-19 17:26 tt.txt.bak

2.创建存储过程

CREATE OR REPLACE PROCEDURE RETRIEVE_LOB_TO_FILE(TEMP_BLOB IN BLOB,
                                                 FILE_PATH IN VARCHAR2,
                                                 FILE_NAME IN VARCHAR2) IS
  DATA_BUFFER   RAW(32767);
  POSITION      INTEGER := 1;
  FILEHANDLE    UTL_FILE.FILE_TYPE;
  ERROR_NUMBER  NUMBER;
  ERROR_MESSAGE VARCHAR2(100);
  BLOB_LENGTH   INTEGER;
  CHUNK_SIZE    BINARY_INTEGER := 32767;
BEGIN
  BLOB_LENGTH := DBMS_LOB.GETLENGTH(TEMP_BLOB);
  FILEHANDLE  := UTL_FILE.FOPEN(FILE_PATH, FILE_NAME, 'wb', 1024);
  WHILE POSITION < BLOB_LENGTH LOOP
    DBMS_LOB.READ(TEMP_BLOB, CHUNK_SIZE, POSITION, DATA_BUFFER);
    UTL_FILE.PUT_RAW(FILEHANDLE, DATA_BUFFER);
    POSITION    := POSITION + CHUNK_SIZE;
    DATA_BUFFER := NULL;
  END LOOP;
  UTL_FILE.FCLOSE(FILEHANDLE);
EXCEPTION
  WHEN OTHERS THEN
    BEGIN
      ERROR_NUMBER  := SQLCODE;
      ERROR_MESSAGE := SUBSTR(SQLERRM, 1, 100);
      DBMS_OUTPUT.PUT_LINE('Error #: ' || ERROR_NUMBER);
      DBMS_OUTPUT.PUT_LINE('Error Message: ' || ERROR_MESSAGE);
      UTL_FILE.FCLOSE_ALL;
    END;
END;
/

3.测试读取blob到系统

SQL> declare 
  2  tmp_blob blob default empty_blob(); 
  3  begin 
  4  dbms_lob.createtemporary(tmp_blob, true); 
  5  select col1 into tmp_blob from blobtest; 
  6  retrieve_lob_to_file (tmp_blob, 'ULTLOBDIR','xifenfei.txt'); 
  7  end;
  8  /

PL/SQL procedure successfully completed.

SQL> !pwd
/home/oracle

SQL> !ls -l xifenfei.txt
-rw-r--r-- 1 oracle oinstall 4829 03-20 23:44 xifenfei.txt
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坏块分类与检测

发表于 2012 年 3 月 20 日 由 惜分飞

很多人都对oracle都知道oracle坏块有逻辑坏块和物理坏块之分，其实根据物理和逻辑坏块的分类，还可以继续分下去；对于坏块的检查，很多人知道物理和逻辑坏块使用dbv和rman检测，那其他种类的坏块该怎么办呢？这篇文章整理自MOS，给大家整理个分析坏块的思路，在后续文章中，会给出各种坏块的解决思路
//www.xifenfei.com/wp-content/uploads/2012/03/Corruption_block_type_and_analysis.pdf
附件:hout和hcheck

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IP=FIRST作用说明

发表于 2012 年 3 月 20 日 由 惜分飞

我相信细心的朋友,估计都会发现我们在使用netca创建rac(10g/11g)的监听的时候，会发现 IP=FIRST,如下面展示

LISTENER_VENUS =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS_LIST =
        (ADDRESS = (PROTOCOL = TCP)(HOST = racnode1-vip)(PORT = 1521)(IP = FIRST))
        (ADDRESS = (PROTOCOL = TCP)(HOST = racnode1)(PORT = 1521)(IP = FIRST))
      )
    )
  )

那么 IP=FIRST表示什么含义呢？我通过下面的试验证明

1. 主机相关配置

[oracle@localhost ~]$ hostname 
localhost.localdomain
[oracle@localhost ~]$ more /etc/hosts
127.0.0.1               localhost.localdomain localhost
[oracle@localhost ~]$ /sbin/ifconfig
eth0      Link encap:Ethernet  HWaddr 00:15:17:67:9C:39  
          inet addr:192.168.8.121  Bcast:192.168.15.255  Mask:255.255.248.0
          inet6 addr: fe80::215:17ff:fe67:9c39/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:378351781 errors:0 dropped:0 overruns:0 frame:0
          TX packets:357773718 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          RX bytes:65412948319 (60.9 GiB)  TX bytes:92608894986 (86.2 GiB)
          Base address:0x1100 Memory:88020000-88040000 

eth0:0    Link encap:Ethernet  HWaddr 00:15:17:67:9C:39  
          inet addr:202.91.244.3  Bcast:202.91.247.255  Mask:255.255.248.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Base address:0x1100 Memory:88020000-88040000 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:40636368 errors:0 dropped:0 overruns:0 frame:0
          TX packets:40636368 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:3385490475 (3.1 GiB)  TX bytes:3385490475 (3.1 GiB)

2. 当前监听配置

SID_LIST_LISTENER =
  (SID_LIST =
      (SID_DESC =
      (SID_NAME = mcrm)
      (ORACLE_HOME = /opt/oracle/product/10.2.0/db_1)
      (GLOBAL_DBNAME =mcrm)
    )

  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = localhost.localdomain)(PORT = 1521)  ) 
)
  )

3. 监听状态

 [oracle@localhost ~]$ lsnrctl status

LSNRCTL for Linux: Version 10.2.0.4.0 - Production on 20-MAR-2012 00:17:04

Copyright (c) 1991, 2007, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost.localdomain)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 10.2.0.4.0 - Production
Start Date                03-MAR-2012 23:56:18
Uptime                    16 days 0 hr. 20 min. 45 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /opt/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File         /opt/oracle/product/10.2.0/db_1/network/log/listener.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=localhost.localdomain)(PORT=1521)))
Services Summary...
Service "mcrm" has 2 instance(s).
  Instance "mcrm", status UNKNOWN, has 1 handler(s) for this service...
  Instance "mcrm", status READY, has 1 handler(s) for this service...
Service "mcrmXDB" has 1 instance(s).
  Instance "mcrm", status READY, has 1 handler(s) for this service...
Service "mcrm_XPT" has 1 instance(s).
  Instance "mcrm", status READY, has 1 handler(s) for this service...
The command completed successfully

这里可以看出来监听的还是(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=localhost.localdomain)(PORT=1521)))，也就是说监听的是主机名

4. 当前监听IP和端口

[oracle@localhost ~]$ netstat -an |grep 1521|grep LISTEN
tcp        0      0 0.0.0.0:1521                0.0.0.0:*                   LISTEN

这里看出来，监听所有网卡

5. 修改监听文件

SID_LIST_LISTENER =
  (SID_LIST =
      (SID_DESC =
      (SID_NAME = mcrm)
      (ORACLE_HOME = /opt/oracle/product/10.2.0/db_1)
      (GLOBAL_DBNAME =mcrm)
    )

  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = localhost.localdomain)(PORT = 1521) (IP=FIRST) ) 
)
  )

6. 重启监听

[oracle@localhost ~]$ lsnrctl stop

LSNRCTL for Linux: Version 10.2.0.4.0 - Production on 20-MAR-2012 00:18:42

Copyright (c) 1991, 2007, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost.localdomain)(PORT=1521)(IP=FIRST)))
The command completed successfully
[oracle@localhost ~]$ lsnrctl start

LSNRCTL for Linux: Version 10.2.0.4.0 - Production on 20-MAR-2012 00:18:47

Copyright (c) 1991, 2007, Oracle.  All rights reserved.

Starting /opt/oracle/product/10.2.0/db_1/bin/tnslsnr: please wait...

TNSLSNR for Linux: Version 10.2.0.4.0 - Production
System parameter file is /opt/oracle/product/10.2.0/db_1/network/admin/listener.ora
Log messages written to /opt/oracle/product/10.2.0/db_1/network/log/listener.log
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0.1)(PORT=1521)))

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost.localdomain)(PORT=1521)(IP=FIRST)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 10.2.0.4.0 - Production
Start Date                20-MAR-2012 00:18:48
Uptime                    0 days 0 hr. 0 min. 0 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /opt/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File         /opt/oracle/product/10.2.0/db_1/network/log/listener.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0.1)(PORT=1521)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "mcrm" has 1 instance(s).
  Instance "mcrm", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully

通过(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=127.0.0.1)(PORT=1521)))，已经发现，这里只监听127.0.0.1

7. 查看监听IP和端口

[oracle@localhost ~]$ netstat -an |grep 1521|grep LISTEN
tcp        0      0 127.0.0.1:1521              0.0.0.0:*                   LISTEN

这里进一步验证监听的ip地址已经只有了127.0.0.1而没有了其他网卡的地址

总结说明
通过这里的试验证明IP = FIRST的作用使得当我们使用主机名为监听中的host配置的时候，它只会监听hostname解析出来的ip地址，而不是默认情况下所有网卡地址。

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