Submitted by yejr on 周五, 2006/04/14 - 09:00
当前MySQL已经支持 ISAM, MyISAM, MEMORY (HEAP) 类型表的表级锁了，BDB 表支持页级锁，InnoDB 表支持行级锁。
很多时候，可以通过经验来猜测什么样的锁对应用程序更合适，不过通常很难说一个锁比别的更好，这全都要依据应用程序来决定，不同的地方可能需要不同的锁。
Submitted by yejr on 周四, 2006/04/13 - 08:55
在一些情况下，MySQL可以直接使用索引来满足一个 ORDER BY 或 GROUP BY 子句而无需做额外的排序。
Submitted by yejr on 周四, 2006/04/13 - 08:54
在大多数情况下，可以通过统计磁盘搜索次数来估算查询的性能。对小表来说，通常情况下只需要搜索一次磁盘就能找到对应的记录（因为索引可能已经缓存起来了）。对大表来说，大致可以这么估算，它使用B树做索引，想要找到一条记录大概需要搜索的次数为：log(row_count) / log(index_block_length / 3 * 2 / (index_length + data_pointer_length)) + 1。
Submitted by yejr on 周四, 2006/04/13 - 08:53
EXPLAIN tbl_name
或者:
EXPLAIN SELECT select_options
EXPLAIN 语句可以被当作 DESCRIBE 的同义词来用，也可以用来获取一个MySQL要执行的 SELECT 语句的相关信息。
-
EXPLAIN tbl_name 语法和 DESCRIBE tbl_name 或 SHOW COLUMNS FROM tbl_name 一样。
Submitted by yejr on 周二, 2006/04/04 - 17:52
come from:http://www.mysql.com
Capgemini Develops "Look-to-Book" Travel Solution to Serve Enquiries
from Sales Points, Internet and Call Centers
Submitted by yejr on 周三, 2006/03/29 - 15:04
come from:http://www.mysql.com
Enterprise Vendors Provide Products & Services that Support Users of the World's Most Popular Open Source Database
Submitted by yejr on 周四, 2006/03/23 - 11:00
come from:http://www.mysql.com
SANTA CLARA, Calif. -- March 20, 2006 -- MySQL AB, developer of the world's most popular open source database, today announced it has joined the Eclipse Foundation as an Add-In Provider. The company plans to contribute work to the Eclipse Data Tools Platform project and collaborate with Zend Technologies and others on the Eclipse PHP IDE project. The announcement was made in advance of the EclipseCon 2006 conference, being held here this week.
Submitted by yejr on 周四, 2006/03/09 - 09:43
come from:http://www.mysql.com
InterBase Creator Jim Starkey Joins New co-CTO Taneli Otala -- Expanding Veteran Tech Experience at Open Source Database Leader
CUPERTINO, Calif. — February 27, 2006 — MySQL AB, developer of the world's most popular open source database, today announced the addition of two well-respected database veterans to its senior engineering management team. Relational database pioneer Jim Starkey, the creator of InterBase, has joined MySQL AB as Senior Software Architect. In addition, the company has appointed Mr. Taneli Otala as co-Chief Technical Officer, a position he will share with MySQL co-founder Michael "Monty" Widenius.
Submitted by yejr on 周二, 2006/03/07 - 10:17
come from:http://www.mysql.com
A few years ago, I wrote an article entitled "The Foundation of Excellent Performance" (still available at http://www.tdan.com/i016fe03.htm) where I argued against the notion that SQL code was the number one contributor to performance in a database-driven system. Instead, I stated in the article that I firmly believed how good physical database design was far and away the leading component of superior database performance. In addition, I showed that Oracle's own research illustrated how poor design was the main culprit behind database downtime (planned or unplanned). In the years since then, I've not changed my stance and still think that any DBA who wants a high-performance database has got to invest in intelligent and savvy physical design to produce the kind of response times that make end users smile instead of scream.
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