V$LATCH

SQL> desc v$latch
 名称                                                                                          是否为空? 类型
 ---------------------------------------------------------------------------------------------- -------- ---------

 ADDR                                                                                                     RAW(4)      ---address of latch object
 LATCH#                                                                                                 NUMBER
 LEVEL#                                                                                                  NUMBER
 NAME                                                                                                     VARCHAR2(50)  ---latch name
 HASH                                                                                                     NUMBER
 GETS                                                                                                      NUMBER    ---成功的以willing-to-wait获取latch次数
 MISSES                                                                                                  NUMBER    ---以willing-to-wait请求latch,等待次数
 SLEEPS                                                                                                  NUMBER    ---以willing-to-wait请求latch,休眠次数
 IMMEDIATE_GETS                                                                                  NUMBER    ---成功的以immediate模式获得latch次数
 IMMEDIATE_MISSES                                                                              NUMBER    ---以immediate模式请求latch不成功次数
 WAITERS_WOKEN                                                                                 NUMBER
 WAITS_HOLDING_LATCH                                                                       NUMBER
 SPIN_GETS                                                                                            NUMBER   ---以willing-to-wait获取latch,自旋的次数
 SLEEP1                                                                                                  NUMBER   ---无用
 SLEEP2                                                                                                  NUMBER   ---无用   
 SLEEP3                                                                                                  NUMBER   ---无用
 SLEEP4                                                                                                  NUMBER   ----这些列都不占成使用了
 SLEEP5                                                                                                  NUMBER
 SLEEP6                                                                                                  NUMBER
 SLEEP7                                                                                                  NUMBER
 SLEEP8                                                                                                  NUMBER
 SLEEP9                                                                                                  NUMBER
 SLEEP10                                                                                                NUMBER
 SLEEP11                                                                                                NUMBER
 WAIT_TIME                                                                                            NUMBER  ----等待一共花费的时间(微妙，百万分之一)