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what does Collapse condition mean?
Posted by: jongse park
Date: April 10, 2011 07:25PM

I read 7.13.1.1. The Range Access Method for Single-Part Indexes in mysql 5.5 manual.
In following;
3.Collapse conditions that are always true or false:
■(key1 LIKE 'abcde%' OR TRUE) is always true
■(key1 < 'uux' AND key1 > 'z') is always false

Are there some case of collapse condition for true or false?
I can't understand for collapse conditions.
What is collapse condition?

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