MySQL Performance: MySQL => Optimizing simple order by query

Members

Help

Home

Home » Performance » MySQL » Optimizing simple order by query

Show: Today's Messages :: Show Polls :: Message Navigator

Optimizing simple order by query [message #3686]

Mon, 03 November 2008 18:53

novice.program
Messages: 1
Registered: November 2008

Junior Member

Hello I am having problems in optimizing a simple order by clause.

the query is:
explain SELECT `Entity`.`title`, `Entity`.`description`, `Entity`.`user_id`, `Entity`.`thumb_url`, `Entity`.`entity_uid`, `Entity`.`num_fachaks`, `Entity`.`number_of_views` FROM `entities` AS `Entity` ORDER BY `Entity`.`created` DESC LIMIT 21 \G
*************************** 1. row ***************************
id: 1
select_type: SIMPLE
table: Entity
type: ALL
possible_keys: NULL
key: NULL
key_len: NULL
ref: NULL
rows: 11
Extra: Using filesort

I have index on the created filed by really dont understand that why mysql does not use it and prefers file sort.. the created field is a timestamp default current_timestamp.

Please help ... i am new to mysql and badly stuck.

Thanks.

Report message to a moderator

Previous Topic:	Increasing performance by parallel processing or multiple mysqld
Next Topic:	ERROR 1041 (HY000) OutOfMemory

Goto Forum:

-=] Back to Top [=-

[ Generate printable PDF ] [ Syndicate this forum (XML) ] [

]

Current Time: Thu Jul 9 19:50:56 EDT 2009

Total time taken to generate the page: 0.01001 seconds

.:: Contact :: Home ::.

MySQL is a trademark of Sun Microsystems.
InnoDB is a trademark of Oracle Corp.

Percona Performance Forums are a service of Percona, Inc.
Not affiliated with Sun Microsystems or Oracle Corp.