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order by primary key slowly
Posted by: varky chan ()
Date: April 05, 2016 10:42PM

There is a user table on my database with InnoDB storage engine like following:

CREATE TABLE user (
id int not null auto_increment,
name varchar(50) not null,
password char(64) not null,
email varchar(80) not null,
primary key (id),
unique key (username)
) Engine=InnoDB;

And about 7 millions user data in it. When i execute some queries as follows:

1. select id from user limit 1000000,10;
2. select id from user order by id desc limit 1000000,10;

The first query above is faster, the second query is very slow. What's happen about the second query? Why it is slow?

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Subject Views Written By Posted
order by primary key slowly 921 varky chan 04/05/2016 10:42PM
Re: order by primary key slowly 410 Øystein Grøvlen 04/06/2016 04:35AM
Re: order by primary key slowly 451 varky chan 04/06/2016 10:15AM
Re: order by primary key slowly 423 Peter Brawley 04/06/2016 11:23AM
Re: order by primary key slowly 496 varky chan 04/06/2016 08:11PM
Re: order by primary key slowly 390 Peter Brawley 04/06/2016 10:35PM
Re: order by primary key slowly 399 varky chan 04/07/2016 12:34AM
Re: order by primary key slowly 439 Øystein Grøvlen 04/07/2016 07:21AM
Re: order by primary key slowly 418 Peter Brawley 04/07/2016 10:20AM
Re: order by primary key slowly 401 varky chan 04/07/2016 11:26PM
Re: order by primary key slowly 396 Rick James 04/12/2016 07:42PM
Re: order by primary key slowly 401 Peter Brawley 04/06/2016 08:57AM
Re: order by primary key slowly 396 varky chan 04/06/2016 10:17AM


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