Oracle Enqueue Lock Type Reference including 11g new locks

内部视图x$ksqst记录了以enqueue type分类的队列管理统计信息(Enqueue management statistics by type)，ksqstwat列反映了等待次数，而ksqstwtim列反映了累积等待时间，实际上v$enqueue_stat动态性能视图的CUM_WAIT_TIME列数据也来源于ksqstwtim:
SQL> select * from v$fixed_view_definition where view_name=upper('gv$enqueue_stat');

VIEW_NAME
------------------------------
VIEW_DEFINITION
--------------------------------------------------------------------------------
GV$ENQUEUE_STAT
select inst_id, ksqsttyp, sum(ksqstreq), sum(ksqstwat), sum(ksqstsgt),
sum(ksqstfgt), sum(ksqstwtm)本文出自 “Ask Maclean Liu Oracle” 博客，请务必保留此出处http://maclean.blog.51cto.com/2923249/1277764