http://www.dbshards.com/articles/database-sharding-whitepapers/:
Auto-increment key management. Typical auto-increment functionality provided by database management systems generate a sequential key for each new row inserted into the database. This is fine for a single database application, but when using Database Sharding, keys must be managed across all shards in a coordinated fashion. The requirement here is to provide a seamless, automated method of key generation to the application, one that operates across all shards, ensuring that keys are unique across the entire system.
我无法理解,我们如何能够为“在所有硬操作的应用程序提供一个无缝的自动关键一代方法。