ITPub博客

install mysql558[@more@]首先阅读下官方文档说明http://dev.mysql.com/doc/refman/5.5/en/source-installation.html按照cmake吧，就不说了,下载源码，改bughttp://bugs.mysql.com/bug.php?id=58350http://lists.mysql.com/commits/126782编译CC='/usr/bin/gcc' CFLAGS='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -fPIC -Wall -O3 -g -static-libgcc -fno-omit-frame-pointer -fno-strict-aliasing -DDBUG_OFF' CXX='/usr/bin/gcc' CXXFLAGS='-O2 -

blob bug[@more@]http://www.mysqlperformanceblog.com/2010/11/29/data-corruption-drbd-and-story-of-bug/http://bugs.mysql.com/bug.php?id=55981root@test 06:52:04>CREATE TABLE t4(c1 int,c2 int,c3 MEDIUMBLOB,PRIMARY KEY(c1)) engine=innodb;Query OK, 0 rows affected (0.01 sec)root@test 06:52:05>insert into t4 values(1, 2, REPEAT('b', 54903));Query OK, 1 row affected (0.04 sec)root@test 06:52:12>start transaction;Query OK, 0 rows affected (0.00 sec)root@test 06:52:18>update t4 set c1 = 3;Quer

service_name or sid[@more@]问题起源于itpub一个帖子http://www.itpub.net/thread-1358298-1-1.html，答案呢，通过service_name实现failover和lb自然是一方面，顺便查了下oracle文档相关介绍，还是有些特别的发现的。http://download.oracle.com/docs/cd/B19306_01/network.102/b14213/tnsnames.htm#sthref754.6.4.8 SERVICE_NAMEPurposeUse the SERVICE_NAME parameter to identify the Oracle9i or Oracle8 database service to access. Set the value to a value specified by the SERVICE_NAMES parameter in the initialization par

Oracle SQL performance with database links - dblink[@more@]http://download.oracle.com/docs/cd/B14117_01/server.101/b10752/hintsref.htm#30401https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&doctype=PROBLEM&id=825677.1http://www.dba-oracle.com/t_sql_dblink_performance.htmhttp://jiri.wordpress.com/2009/05/20/queries-across-db-link-and-how-driving_site-hint-does-not-work-for-inserts/http://psoug.org/reference/hints.html

Surge Scalability 2010[@more@]Surge Scalability 2010，值得关注下，转一位speaker的演讲概要在这里，希望有所启发。http://ronaldbradford.com/blog/speaking-at-surge-scalability-2010-2010-07-28/Overview:Some details of the presentation would include:The different types of accessible data (e.g. R/W, R, none) What limits MySQL availability (e.g software upgrades, blocking statements, locking etc)The three components of scalability – Read Scalability/Write Scalability/CachingDesign practices for increa

http://mituzas.lt/2010/06/30/replication/[@more@]http://mituzas.lt/2010/06/30/replication/很是认同，转载下There are few things one is supposed to know about MySQL replication in production, as manual doesn’t always discuss things openly.This is small set of rules and advices I compiled (some apply to statement based replication only, but row based replication may benefit from one or two too):Don’t use MyISAM. Or in fact, don’t use any non-transactional engine, if you care about your data. On

作者: 弦乐之花 | 可以转载, 但必须以超链接形式标明文章原始出处和作者信息及版权声明链接http://shiri512003.itpub.net/post/37713/501173[@more@]5148的发布把innodb plugin带入了1.0.9时代，5147innodb plugin更新到了108版本还是马马虎虎能接受，5148的109版本真是乱来了，大家可以看下109的版本变化，innodb本身没有任何变化嘛。。。http://dev.mysql.com/doc/refman/5.1/en/news-5-1-48.htmlInnoDB Plugin has been upgraded to version 1.0.9. This version is considered of General Availability (GA) quality. InnoDB Plugin C

作者: 弦乐之花 | 可以转载, 但必须以超链接形式标明文章原始出处和作者信息及版权声明链接http://shiri512003.itpub.net/post/37713/501132 [@more@]最近没太关注percona分支的mysql5145以上版本了，（其实也是一直很期待基于5147的percona版出现的）今天偶然发现percona已经是发布了5.1.47-11.0，（oracle已经release了5148版，细细看了release note，没有升级的欲望也是）于是下来测试一把，发现还是有点意思的首先看下configue命令的帮助，比较有趣的percona把builtin版本的编译选项修改成只支持动态编译，plugin则支持动静态编译，刚

ibdata1[@more@]记得之前曾在Pub上看到innodb共享表空间暴涨的案例，自己在实际测试中也遇到多（高并发情况），其中缘由也是知晓一二，今天看到peter的两篇博文进行了详细的描述，简单记录下来备查。http://www.mysqlperformanceblog.com/2010/06/10/purge-thread-spira-of-death/I just wrote a large post on reasons for innodb main tablespace excessive growth and I thought it would make sense to explain briefly of why it is so frequently you have purge not being the problem at all and when out of no where you can se

_optimizer_compute_index_stats[@more@]COMPUTE STATISTICS In earlier releases, you could use this clause to start or stop the collection of statistics on an index. This clause has been deprecated. Oracle Database now automatically collects statistics during index creation and rebuild. This clause is supported for backward compatibility and will not cause errors._optimizer_compute_index_stats

文章收集[@more@]fast paging in the real worldhttp://cafuego.net/2010/05/26/fast-paging-real-worldFixing MySQL group commit http://kristiannielsen.livejournal.com/12254.htmlOn Good Instrumentationhttp://www.mysqlperformanceblog.com/2010/05/31/on-good-instrumentation/

oracle之commit控制[@more@]_lgwr_async_io_wait_for_synccommit_writehttp://download.oracle.com/docs/cd/E11882_01/server.112/e10820/initparams032.htm#REFRN10260http://www.oracle-base.com/articles/10g/Commit_10gR2.phpcommit_waithttp://download.oracle.com/docs/cd/E11882_01/server.112/e10820/initparams031.htm#REFRN10266commit_logginghttp://download.oracle.com/docs/cd/E11882_01/server.112/e10820/initparams029.htm#REFRN10265

http://www.linuxsong.org/2008/08/shell_05.html[@more@]Shell中如何按列求和？ 转载http://www.linuxsong.org/2008/08/shell_05.html在Shell中，我们可以用awk实现按列求和的功能，非常简单。看下面的例子：1.简单的按列求和[linux@test /tmp]$ cat test123.52125.54126.36[linux@test /tmp]$ awk '{sum += $1};END {print sum}' test375.422.对符合某些条件的行，按列求和[linux@test /tmp]$ cat testaaa 123.52bbb 125.54aaa 123.52aaa 123.52ccc 126.36对文件test中 第一列为aaa的行求和[linux@test /tmp]$ awk '/aaa/ {sum += $2};E

作者: 弦乐之花 | 可以转载, 但必须以超链接形式标明文章原始出处和作者信息及版权声明链接http://shiri512003.itpub.net/post/37713/500220[@more@]我们特别是oracle dbas常常会通过ctas来复制表结构，这样复制出来的表实际上会丢掉表的一些属性，索引就更不说了，在mysql中这样来复制表其实得到的也只是表大体结构而已。还好mysql提供了create table like命令方便进行表结构的复制，废话不说了root@mysql 02:55:17>use testDatabase changedroot@test 03:25:22>create table t1(a int,b int,key (a)) engine=myisam;Query OK, 0 r

test[@more@]InnoDB Plugin has been upgraded to version 1.0.8http://dev.mysql.com/doc/refman/5.1/en/news-5-1-47.html目前能看到的plugin本身的改进并不多，不知道正式发布后的change log list能有多长。对于选择plugin版本的用户而言，希望percona&google&facebook这些分支所提供的一些优秀的patch，能够尽快经过innodb的测试认可，这样大家可以在收到性能收益的时候，也能更加安心的使用，个人而言是把innodb作为稳定性测试的最后一道卡。InnoDB stores redo log records in a hash table during recovery. On 64-bit syst

http://www.theopenforce.com/2010/05/more_brainstorm.html[@more@]转载自http://www.theopenforce.com/2010/05/more_brainstorm.htmlMake it safe to contribute ideasThe best way to do this is encourage risk taking and acknowledge that some ideas will fail and that's acceptable. The people I know who are the most creative are also the most prolific when it comes to idea generation. And some of those ideas are, objectively speaking, total crap. But there are so many good ideas generated in the process

http://www.theopenforce.com/2010/05/brainstorm.htmlhttp://mysqlmusings.blogspot.com/2006/08/two-more-ways-to-kill-good-ideas.html [@more@]转载自http://www.theopenforce.com/2010/05/brainstorm.htmlThis past week I was in a couple of different strategic planning meetings. Some sessions were noticeably more effective than others in encouraging creative ideas. I started to wonder why that is and came up with the top ways to kill new ideas. If you see these tenets taking hold in your organization, the

DBI@[@more@]简单记录下先http://search.cpan.org/~timb/DBI/DBI.pm#DBI_Constantshttp://perl.enstimac.fr/perl5.6.1/site_perl/5.6.1/sun4-solaris/DBD/Oracle.html#item_ora_type foreach (@{ $DBI::EXPORT_TAGS{sql_types} }) { printf "%s=%dn", $_, &{"DBI::$_"}; }

作者: 弦乐之花 | 可以转载, 但必须以超链接形式标明文章原始出处和作者信息及版权声明链接http://shiri512003.itpub.net/post/37713/499937[@more@]mysql innodb之select for update nowait习惯了oracle数据库的select for update nowait的同学，如果转在mysql环境开发的话，也许会不太适应——目前builtin版本的innodb不支持nowait句法的。早在08年已经被作为bug提了出来（http://bugs.mysql.com/bug.php?id=36285）。还好innodb plugin1.0.2开始支持bug文章里提及的session级innodb_lock_wait_timeout控制（http://dev.mysql.com/doc/i

作者: 弦乐之花 | 可以转载, 但必须以超链接形式标明文章原始出处和作者信息及版权声明链接http://shiri512003.itpub.net/post/37713/499911[@more@]在一组测试中发现并发从14到150（16core）性能有50%+的下降：#测试是通过sysbench进行的Activ Cmmit C_sel C_ins C_del C_upd15 24K 333K 24K 24K 71K14 25K 343K 25K 25K 74K13 24K 329K 24K 24K 71K15 24K 331K 24K 24K 71K16 24K 336K 24K 24K 72K16 24K 341K 24K 24K 73K16 23K 327K 23K 23K 70K12 23K 324K 23K 23K 69KActiv Cmmit C_sel C_ins C_del C_upd 149 8216 164K 8214 8214