<?xml version="1.0" encoding="gb2312"?>
<feed version="0.3" xmlns="http://purl.org/atom/ns#" xmlns:dc="http://purl.org/dc/elements/1.1/" xml:lang="zh-cn">
    
    <title>mengxb001</title> 
<link rel="alternate" type="text/html" href="http://mengxb001.itpub.net" /> 
 
<modified>Fri,19 03 2010 05:06:09</modified> 
<tagline></tagline> 
<generator url="http://www.plogworld.net/" version="1.0.1">pLog</generator> 
 
<copyright>Copyright (c) mengxb001</copyright> 
    
 <entry> 
 <id>tag:post:blog.itpub.net,Thu,13 12 2007 09:38:28</id>
 <title>topas问题</title> 
 <link rel="alternate" type="text/html" href="http://mengxb001.itpub.net/post/22771/434806" /> 
  
 <modified>Thu,13 12 2007 09:38:28</modified> 
 <issued>Thu,13 12 2007 09:38:28</issued> 
 <created>Thu,13 12 2007 09:38:28</created> 
 <summary type="text/plain"> topas KBPS问题AIX 5.1man topasKBPSThe number of kilobytes read and written per second over the monitoringinterval. This field is the sum of KB-Read and KB-Read. Disk Busy% KBPS TPS KB-Read KB-Writhdisk43 5.5 1336.6 29 8.0 2665.3hdisk81 3.0 1345.6 27 0.0 2691.3hdisk54 1.0 12.0 1 24.0 0.0hdisk23 1.0 16.0 2 32.0 0.0hdisk31 0.5 4.0 0 8.0 0.0hdisk0 0.5 2.0 0 4.0 0.0hdisk4 0.5 4.0 1 8.0 0.0hdisk51 0.0 0.0 0 0.0 0.0hdisk63 0.0 16.0 2 0.0 32.0hdisk46 0.0 0.0 0 0.0 0.0hdisk20 0.0 0.0 0 0.0 0.0hdisk22 0.0...</summary> 
 <author> 
  
 <name>mengxb001</name> 
 <url>http://mengxb001.itpub.net</url> 
 <email>mxb_1007@163.com</email> 
</author> 
<dc:subject>
UNIX
</dc:subject> 
 <content type="text/html" mode="escaped" xml:lang="zh-cn" xml:base="http://mengxb001.itpub.net"> 
 topas KBPS问题AIX 5.1man topasKBPSThe number of kilobytes read and written per second over the monitoringinterval. This field is the sum of KB-Read and KB-Read. Disk Busy% KBPS TPS KB-Read KB-Writhdisk43 5.5 1336.6 29 8.0 2665.3hdisk81 3.0 1345.6 27 0.0 2691.3hdisk54 1.0 12.0 1 24.0 0.0hdisk23 1.0 16.0 2 32.0 0.0hdisk31 0.5 4.0 0 8.0 0.0hdisk0 0.5 2.0 0 4.0 0.0hdisk4 0.5 4.0 1 8.0 0.0hdisk51 0.0 0.0 0 0.0 0.0hdisk63 0.0 16.0 2 0.0 32.0hdisk46 0.0 0.0 0 0.0 0.0hdisk20 0.0 0.0 0 0.0 0.0hdisk22 0.0...</content> 
</entry> 

 <entry> 
 <id>tag:post:blog.itpub.net,Sun,29 07 2007 09:23:34</id>
 <title>碰到BUG了</title> 
 <link rel="alternate" type="text/html" href="http://mengxb001.itpub.net/post/22771/318699" /> 
  
 <modified>Sun,29 07 2007 09:23:34</modified> 
 <issued>Sun,29 07 2007 09:23:34</issued> 
 <created>Sun,29 07 2007 09:23:34</created> 
 <summary type="text/plain"> AIX Version 5.1$uptime09:03AM up 13723 days, 1:01, 3 users, load average: 3.02, 3.05, 3.42这个主机已经运行了37.5年了！今天在AIX主机上的主机碰到问题了，undo慢了后，报错，查询dba_undo_extents报ORA-00600错误，在metalink上查看是一个在9205上的一个已知的bug，查看一下竟然没有针对IBM的补丁，如果要姐姐只能升级到大版本。</summary> 
 <author> 
  
 <name>mengxb001</name> 
 <url>http://mengxb001.itpub.net</url> 
 <email>mxb_1007@163.com</email> 
</author> 
<dc:subject>
Oracle
</dc:subject> 
 <content type="text/html" mode="escaped" xml:lang="zh-cn" xml:base="http://mengxb001.itpub.net"> 
 AIX Version 5.1$uptime09:03AM up 13723 days, 1:01, 3 users, load average: 3.02, 3.05, 3.42这个主机已经运行了37.5年了！今天在AIX主机上的主机碰到问题了，undo慢了后，报错，查询dba_undo_extents报ORA-00600错误，在metalink上查看是一个在9205上的一个已知的bug，查看一下竟然没有针对IBM的补丁，如果要姐姐只能升级到大版本。</content> 
</entry> 

 <entry> 
 <id>tag:post:blog.itpub.net,Tue,03 04 2007 08:58:13</id>
 <title>在什么情况下,oracle会认为已经统计的信息失效</title> 
 <link rel="alternate" type="text/html" href="http://mengxb001.itpub.net/post/22771/276800" /> 
  
 <modified>Tue,03 04 2007 08:58:13</modified> 
 <issued>Tue,03 04 2007 08:58:13</issued> 
 <created>Tue,03 04 2007 08:58:13</created> 
 <summary type="text/plain"> 在什么情况下,oracle会认为已经统计的信息失效在什么情况下,oracle会认为已经统计的信息失效,需要对表进行分析比如说一个表在昨天分析的,根据分析后结果看到当时的记录条数是1000条,而从DBA_TAB_MODIFICATIONS表种看到的inserts为10,updates为10,deletes为10,inserts+updates+deletes=3030/1000*100%=3%,所以不用对这个表分析Note that both gather stale and gather auto require monitoring. If you issue the “alter table xxx monitoring” command, Oracle tracks changed tables with the dba_tab_modifications view. Below we se...</summary> 
 <author> 
  
 <name>mengxb001</name> 
 <url>http://mengxb001.itpub.net</url> 
 <email>mxb_1007@163.com</email> 
</author> 
<dc:subject>
Oracle
</dc:subject> 
 <content type="text/html" mode="escaped" xml:lang="zh-cn" xml:base="http://mengxb001.itpub.net"> 
 在什么情况下,oracle会认为已经统计的信息失效在什么情况下,oracle会认为已经统计的信息失效,需要对表进行分析比如说一个表在昨天分析的,根据分析后结果看到当时的记录条数是1000条,而从DBA_TAB_MODIFICATIONS表种看到的inserts为10,updates为10,deletes为10,inserts+updates+deletes=3030/1000*100%=3%,所以不用对这个表分析Note that both gather stale and gather auto require monitoring. If you issue the “alter table xxx monitoring” command, Oracle tracks changed tables with the dba_tab_modifications view. Below we se...</content> 
</entry> 

 <entry> 
 <id>tag:post:blog.itpub.net,Fri,19 01 2007 15:01:27</id>
 <title>打破血狼的copy测试结果</title> 
 <link rel="alternate" type="text/html" href="http://mengxb001.itpub.net/post/22771/253117" /> 
  
 <modified>Fri,19 01 2007 15:01:27</modified> 
 <issued>Fri,19 01 2007 15:01:27</issued> 
 <created>Fri,19 01 2007 15:01:27</created> 
 <summary type="text/plain"> 自己今天了下copy的试验，采用两个实例，copy采用不同方式(create,insert,append,replace)测试过程中，copy一个10G大小大的表，undo的freespace不足100M，过程中发现undo一直在变化，证实了copy和dml操作是同应的效果，看来还是采用DB_LINK＋DDL倒数据的好，copy的一个优点就是可以分批提交，可以减少对网络的压力。</summary> 
 <author> 
  
 <name>mengxb001</name> 
 <url>http://mengxb001.itpub.net</url> 
 <email>mxb_1007@163.com</email> 
</author> 
<dc:subject>
Oracle
</dc:subject> 
 <content type="text/html" mode="escaped" xml:lang="zh-cn" xml:base="http://mengxb001.itpub.net"> 
 自己今天了下copy的试验，采用两个实例，copy采用不同方式(create,insert,append,replace)测试过程中，copy一个10G大小大的表，undo的freespace不足100M，过程中发现undo一直在变化，证实了copy和dml操作是同应的效果，看来还是采用DB_LINK＋DDL倒数据的好，copy的一个优点就是可以分批提交，可以减少对网络的压力。</content> 
</entry> 

 <entry> 
 <id>tag:post:blog.itpub.net,Wed,17 01 2007 19:18:46</id>
 <title>使用chr(39)或者''代替“  '  ”</title> 
 <link rel="alternate" type="text/html" href="http://mengxb001.itpub.net/post/22771/252187" /> 
  
 <modified>Wed,17 01 2007 19:18:46</modified> 
 <issued>Wed,17 01 2007 19:18:46</issued> 
 <created>Wed,17 01 2007 19:18:46</created> 
 <summary type="text/plain"> select 'alter system kill session '||chr(39)||sid||','||serial#||chr(39)||';' from v$session=select 'alter system kill session '||''''||sid||','||serial#||''''||';' from v$session</summary> 
 <author> 
  
 <name>mengxb001</name> 
 <url>http://mengxb001.itpub.net</url> 
 <email>mxb_1007@163.com</email> 
</author> 
<dc:subject>
Oracle
</dc:subject> 
 <content type="text/html" mode="escaped" xml:lang="zh-cn" xml:base="http://mengxb001.itpub.net"> 
 select 'alter system kill session '||chr(39)||sid||','||serial#||chr(39)||';' from v$session=select 'alter system kill session '||''''||sid||','||serial#||''''||';' from v$session</content> 
</entry> 

 <entry> 
 <id>tag:post:blog.itpub.net,Tue,16 01 2007 19:39:13</id>
 <title>怎么样加密存储过程</title> 
 <link rel="alternate" type="text/html" href="http://mengxb001.itpub.net/post/22771/252189" /> 
  
 <modified>Tue,16 01 2007 19:39:13</modified> 
 <issued>Tue,16 01 2007 19:39:13</issued> 
 <created>Tue,16 01 2007 19:39:13</created> 
 <summary type="text/plain"> 用wrap命令，如（假定你的存储过程保存为a.sql）wrap iname=a.sqlPL/SQL Wrapper: Release 9.2.0.1.0 - Production on Tue JAN 16 22:26:48 2007Copyright (c) Oracle Corporation 1998, 2000. All Rights Reserved.Processing a.sql to a.plb提示a.sql转换为a.plb，这就是加密了的脚本，执行a.plb即可生成加密了的存储过程</summary> 
 <author> 
  
 <name>mengxb001</name> 
 <url>http://mengxb001.itpub.net</url> 
 <email>mxb_1007@163.com</email> 
</author> 
<dc:subject>
Oracle
</dc:subject> 
 <content type="text/html" mode="escaped" xml:lang="zh-cn" xml:base="http://mengxb001.itpub.net"> 
 用wrap命令，如（假定你的存储过程保存为a.sql）wrap iname=a.sqlPL/SQL Wrapper: Release 9.2.0.1.0 - Production on Tue JAN 16 22:26:48 2007Copyright (c) Oracle Corporation 1998, 2000. All Rights Reserved.Processing a.sql to a.plb提示a.sql转换为a.plb，这就是加密了的脚本，执行a.plb即可生成加密了的存储过程</content> 
</entry> 

 <entry> 
 <id>tag:post:blog.itpub.net,Mon,15 01 2007 14:56:20</id>
 <title>行列转换</title> 
 <link rel="alternate" type="text/html" href="http://mengxb001.itpub.net/post/22771/251451" /> 
  
 <modified>Mon,15 01 2007 14:56:20</modified> 
 <issued>Mon,15 01 2007 14:56:20</issued> 
 <created>Mon,15 01 2007 14:56:20</created> 
 <summary type="text/plain"> SQL&gt; select * from test; A B C---------- ---------- ---------- 11 1 .5 11 2 .21 11 3 .25 12 1 .24 12 2 .3 12 3 .226 rows selected.SQL&gt; select a, 2 sum(decode(b,1,c)) xiangmu1, 3 sum(decode(b,2,c)) xiangmu2, 4 sum(decode(c,3,c)) xiangmu3 5 from test 6 group by a; A XIANGMU1 XIANGMU2 XIANGMU3---------- ---------- ---------- ---------- 11 .5 .21 12 .24 .3SQL&gt; l 1 select a, 2 sum(decode(b,1,c)) xiangmu1, 3 sum(decode(b,2,c)) xiangmu2, 4 sum(decode(c,3,c)) xiangmu3 5 from test 6* group by aSQL&gt; l4 4*...</summary> 
 <author> 
  
 <name>mengxb001</name> 
 <url>http://mengxb001.itpub.net</url> 
 <email>mxb_1007@163.com</email> 
</author> 
<dc:subject>
Oracle
</dc:subject> 
 <content type="text/html" mode="escaped" xml:lang="zh-cn" xml:base="http://mengxb001.itpub.net"> 
 SQL&gt; select * from test; A B C---------- ---------- ---------- 11 1 .5 11 2 .21 11 3 .25 12 1 .24 12 2 .3 12 3 .226 rows selected.SQL&gt; select a, 2 sum(decode(b,1,c)) xiangmu1, 3 sum(decode(b,2,c)) xiangmu2, 4 sum(decode(c,3,c)) xiangmu3 5 from test 6 group by a; A XIANGMU1 XIANGMU2 XIANGMU3---------- ---------- ---------- ---------- 11 .5 .21 12 .24 .3SQL&gt; l 1 select a, 2 sum(decode(b,1,c)) xiangmu1, 3 sum(decode(b,2,c)) xiangmu2, 4 sum(decode(c,3,c)) xiangmu3 5 from test 6* group by aSQL&gt; l4 4*...</content> 
</entry> 

 <entry> 
 <id>tag:post:blog.itpub.net,Sun,14 01 2007 16:15:24</id>
 <title>又是字符集问题</title> 
 <link rel="alternate" type="text/html" href="http://mengxb001.itpub.net/post/22771/251126" /> 
  
 <modified>Sun,14 01 2007 16:15:24</modified> 
 <issued>Sun,14 01 2007 16:15:24</issued> 
 <created>Sun,14 01 2007 16:15:24</created> 
 <summary type="text/plain"> cp之间没有设置字符集，导致倒进去的数据显示为乱码</summary> 
 <author> 
  
 <name>mengxb001</name> 
 <url>http://mengxb001.itpub.net</url> 
 <email>mxb_1007@163.com</email> 
</author> 
<dc:subject>
Oracle
</dc:subject> 
 <content type="text/html" mode="escaped" xml:lang="zh-cn" xml:base="http://mengxb001.itpub.net"> 
 cp之间没有设置字符集，导致倒进去的数据显示为乱码</content> 
</entry> 

 <entry> 
 <id>tag:post:blog.itpub.net,Thu,11 01 2007 09:30:22</id>
 <title>判断字段中是否含有中文字符</title> 
 <link rel="alternate" type="text/html" href="http://mengxb001.itpub.net/post/22771/250340" /> 
  
 <modified>Thu,11 01 2007 09:30:22</modified> 
 <issued>Thu,11 01 2007 09:30:22</issued> 
 <created>Thu,11 01 2007 09:30:22</created> 
 <summary type="text/plain"> length是字的长度，lengthb是字节的长度，字符集为UTF8SQL&gt; create table test(a varchar2(20));Table createdSQL&gt; insert into test values('2');1 row insertedSQL&gt; insert into test values('12');1 row insertedSQL&gt; insert into test values('四大皆空');1 row insertedSQL&gt; commit;Commit completeSQL&gt; select * from test;A--------------------212四大皆空SQL&gt; select a from test where length(a)!=lengthb(a);A--------------------四大皆空SQL&gt; select a from test where asciistr(a) not like '%%';A--------------------212S...</summary> 
 <author> 
  
 <name>mengxb001</name> 
 <url>http://mengxb001.itpub.net</url> 
 <email>mxb_1007@163.com</email> 
</author> 
<dc:subject>
Oracle
</dc:subject> 
 <content type="text/html" mode="escaped" xml:lang="zh-cn" xml:base="http://mengxb001.itpub.net"> 
 length是字的长度，lengthb是字节的长度，字符集为UTF8SQL&gt; create table test(a varchar2(20));Table createdSQL&gt; insert into test values('2');1 row insertedSQL&gt; insert into test values('12');1 row insertedSQL&gt; insert into test values('四大皆空');1 row insertedSQL&gt; commit;Commit completeSQL&gt; select * from test;A--------------------212四大皆空SQL&gt; select a from test where length(a)!=lengthb(a);A--------------------四大皆空SQL&gt; select a from test where asciistr(a) not like '%%';A--------------------212S...</content> 
</entry> 

 <entry> 
 <id>tag:post:blog.itpub.net,Mon,08 01 2007 19:30:32</id>
 <title>copy command</title> 
 <link rel="alternate" type="text/html" href="http://mengxb001.itpub.net/post/22771/248791" /> 
  
 <modified>Mon,08 01 2007 19:30:32</modified> 
 <issued>Mon,08 01 2007 19:30:32</issued> 
 <created>Mon,08 01 2007 19:30:32</created> 
 <summary type="text/plain"> 有人说SQL*Plus Copy Command复制数据时不经过Buffer，不写回滚段，copy不产生undo，所以速度是非常快的,但是还是产生大量的归档，比CTAS还要大；而有人经过实验发现SQL*Plus Copy Command并不像想象中的那么快，甚至慢得让人难以接受。对于数据的复制，我也曾经测试过CTAS这种方法还是不错的，不会产生undo，CTAS是ddl操作，速度应该是最快的，不过CTAS过程中会用到temp表空间，难道真是象drop表一样，先把表改成temp表交给smon处理。copy具体测试步骤如下：SQL&gt; conn mxb/mxb;已连接。SQL&gt; select a.file_id &quot;文件号&quot;,a.tablespace_name...</summary> 
 <author> 
  
 <name>mengxb001</name> 
 <url>http://mengxb001.itpub.net</url> 
 <email>mxb_1007@163.com</email> 
</author> 
<dc:subject>
Oracle
</dc:subject> 
 <content type="text/html" mode="escaped" xml:lang="zh-cn" xml:base="http://mengxb001.itpub.net"> 
 有人说SQL*Plus Copy Command复制数据时不经过Buffer，不写回滚段，copy不产生undo，所以速度是非常快的,但是还是产生大量的归档，比CTAS还要大；而有人经过实验发现SQL*Plus Copy Command并不像想象中的那么快，甚至慢得让人难以接受。对于数据的复制，我也曾经测试过CTAS这种方法还是不错的，不会产生undo，CTAS是ddl操作，速度应该是最快的，不过CTAS过程中会用到temp表空间，难道真是象drop表一样，先把表改成temp表交给smon处理。copy具体测试步骤如下：SQL&gt; conn mxb/mxb;已连接。SQL&gt; select a.file_id &quot;文件号&quot;,a.tablespace_name...</content> 
</entry> 
     </feed>


