在之前版本，碎片回收操作是主執行緒的一部分，這經定期排程的方式執行，但會阻塞資料庫的其他操作；[@more@]到5.5以後，可以將這個執行緒獨立出來；方法：innodb_purge_threads =1
這個應該能讓碎片回收得更及時而且不影響其他執行緒的操作；
Improved Purge Scheduling
- The InnoDB purge operation is a type of garbage collection that runs
periodically. In previous versions, the purge was part of the master thread, meaning that it could
block other database operations when running. In MySQL 5.5 this operation can run in its own
thread, allowing for more concurrency. Users can control whether the purge operation is split into its
own thread with the innodb_purge_threads configuration option, which can be set to 0 (the
default) or 1 (for a single separate purge thread).

MySQL 5.5 -- innodb_purge_threads

相關文章