sql
http://www.infoq.com/news/2011/02/SQL-Sharding/
http://channel9.msdn.com/Shows/Data-Exposed/SqlDbShardingIntro
http://enzosqlshard.codeplex.com/
https://enzosqlshard.codeplex.com/downloads/get/687199
http://www.cubrid.org/blog/cubrid-life/database-sharding-with-cubrid/
mysql
http://dbanotes.net/database/database_sharding-2.html
http://eddysheng.iteye.com/blog/461393
http://assets.en.oreilly.com/1/event/74/Massively%20Sharded%20MySQL%20at%20Tumblr%20Presentation.pdf