Oracle parent latch and children latch

About parent vs child latches. There is no fundamental low level difference between parent and child latches, they are all small regions of memory modified with atomic test-and-set style Opcodes.

 

You see parent (and solitary) latches from x $ ksllt where kslltcnm = 0 and child latches have kslltcnm> 0 (their child number is stored there ).

 

V $ latch_parent shows all latches with kslltcnm 0, V $ latch_children shows all latches with CNM> 0. V $ latch just summarizes & groups all statistics up using the latch number, it doesn't care about parent vs child latches.

 

It's up to Oracle, how it uses the child and parent latches, normally when child latches are used, parent latches don't get used much (or at all ), since all resources to be protected have been spread between child latches already.

 

Today, when I see latch in the book, I mentioned two views v $ latch_children andV $ latch_parent. I don't know the difference between the two. I went to Baidu for a while, but Google found a related article.Article.

After reading the above explanation, I personally understand thatThere is no difference between the two. It depends entirely on how oracle is used.