2014年5月25日

MySQL exists的用法介绍

摘要: 有一个查询如下:SELECT c.CustomerId, CompanyName FROM Customers c WHERE EXISTS( SELECT OrderID FROM Orders o WHERE o.CustomerID = cu.CustomerI... 阅读全文

posted @ 2014-05-25 21:18 Still water run deep 阅读(737) 评论(0) 推荐(0) 编辑

2014年5月15日

Don’t Assume – Per Session Buffers

摘要: MySQL has a number of global buffers, i.e. your SGA. There are also a number of per session/thread buffers that combined with other memory usage const... 阅读全文

posted @ 2014-05-15 02:29 Still water run deep 阅读(350) 评论(0) 推荐(0) 编辑

2014年5月13日

MySQL 5.5: InnoDB Change Buffering

摘要: To speed up bulk loading of data, InnoDB implements aninsert buffer, a special index in the InnoDB system tablespace that buffers modifications to sec... 阅读全文

posted @ 2014-05-13 16:21 Still water run deep 阅读(1033) 评论(0) 推荐(0) 编辑

2014年4月29日

Fixing Poor MySQL Default Configuration Values

摘要: I've recently been accumulating some MySQL configuration variables that have defaults which have proven to be problematic in a high-volume production ... 阅读全文

posted @ 2014-04-29 00:53 Still water run deep 阅读(253) 评论(0) 推荐(0) 编辑

2014年4月28日

A quest for the full InnoDB status

摘要: When running InnoDB you are able to dig into the engine internals, look at various gauges and counters, see past deadlocks and the list of all open tr... 阅读全文

posted @ 2014-04-28 23:48 Still water run deep 阅读(228) 评论(0) 推荐(0) 编辑

MySQL : interactive_timeout v/s wait_timeout

摘要: Most of the database intensive applications are worring about the default values of these variables obviously. Developers used to inform me that they ... 阅读全文

posted @ 2014-04-28 23:22 Still water run deep 阅读(438) 评论(0) 推荐(0) 编辑

Mydumper & Myloader Documentation

摘要: Mydumper.org web site has been missing in action for a while now. I've uploaded a copy of the Mydumper documentation to this web site for easy referen... 阅读全文

posted @ 2014-04-28 22:26 Still water run deep 阅读(586) 评论(0) 推荐(0) 编辑

2014年4月11日

InnoDB Plugin文件格式(概述)

摘要: 本文将介绍InnoDB Plugin数据表格式的基本概念。1. 配置参数innodb_file_format这是一个很容易混淆的概念。目前,在InnoDB Plugin(1.0.6)配置文件中innodb_file_format支持两种:Antelope/ˈæntɪləʊp/、Barracuda/ˌbærəˈkjuːdə/。他们分别是两种文件格式的代号,在未来版本中,InnoDB将继续延续这种代号机制,它们会是Antelope, Barracuda, Cheetah, Dragon, Elk, Fox等等。Antelope是Built-in-InnoDB(MySQL内置的I 阅读全文

posted @ 2014-04-11 21:27 Still water run deep 阅读(520) 评论(0) 推荐(0) 编辑

innodb_strict_mode

摘要: Wheninnodb_strict_modeisON,InnoDBreturns errors rather than warnings for certain conditions. The default value isOFF.Strict modehelps guard against ignored typos and syntax errors in SQL, or other unintended consequences of various combinations of operational modes and SQL statements. Wheninnodb_str 阅读全文

posted @ 2014-04-11 21:10 Still water run deep 阅读(1897) 评论(0) 推荐(0) 编辑

2014年4月4日

Comparison of B-Tree and Hash Indexes

摘要: Understanding the B-tree and hash data structures can help predict how different queries perform on different storage engines that use these data structures in their indexes, particularly for theMEMORYstorage engine that lets you choose B-tree or hash indexes.B-Tree Index CharacteristicsA B-tree ind 阅读全文

posted @ 2014-04-04 01:24 Still water run deep 阅读(235) 评论(0) 推荐(0) 编辑

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