Before examining the running speed of the time joomla
Found that he had a particularly slow update
Found that one of the following picture
 
 
 
After inquiry
So this update is in debug mode will be executed
So usually does not perform
Do not care about this query
 
https://groups.google.com/forum/#!topic/joomla-dev-cms/ONYOhXk5ymc
 
 
 
 
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Digression
 
While the speed of the site can be used to improve the staging mechanism
But joomla staging mechanism is not perfect
Because he record scratch is to use block
The block has no sub-URL information to scratch
So the original function is not easy to scratch
 
Do not know if with a plug for ways to improve this problem
This still need to study