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MySQL Explain rows limit
Posted by: Raza Shah ()
Date: October 13, 2013 02:06AM

Does mysql LIMIT is taken into account when estimating number of rows in Explain?
I have below query to get records with genre_id = 1 from content table. There are total 654 records in the table with genre_id 1. I have index on post_id.

SELECT * FROM (`content`)
WHERE `genre_id ` = '1'
AND `category` = 1

And EXPLAIN output:
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE content ref genre_id genre_id 4 const 654 Using where

Now if you notice in explain it is returning 654 rows count, should not it limit to 20 instead getting all those rows?


Thanks for any help.

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Subject Views Written By Posted
MySQL Explain rows limit 2149 Raza Shah 10/13/2013 02:06AM
Re: MySQL Explain rows limit 823 Rick James 10/13/2013 11:55PM
Re: MySQL Explain rows limit 604 Øystein Grøvlen 10/15/2013 07:46AM

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