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Mysql_num_rows VS COUNT Efficiency problem Analysis _php Tutorial

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Author: User
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Mysql_num_rows and COUNT (*) can count the total, that can be better?
Or
When do you use Num_rows and COUNT (*) separately?

An intuitive contrast
Test data:
Number of articles: 139,764
Data table Size: 500M

Results:
Fetch_num_rows spents: 35.272329092026
COUNT (*) spents: 0.071956872940063

If the purely statistical quantity is of course count (*)
Fetch_num_rows must traverse the database to get less efficient than count (*)

http://www.bkjia.com/PHPjc/323250.html www.bkjia.com true http://www.bkjia.com/PHPjc/323250.html techarticle Mysql_num_rows and COUNT (*) can count the total, that can be better? or when to use Num_rows and COUNT (*) separately? An intuitive comparison test data: Number of bars: 13976 ...

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