Title: 네이버 메일
 |
|
|
홍순태 (javahong) 님께 보내신 메일 <Re: mutiple-column index and sorting (DESC)>
이 다음과 같은 이유로 전송 실패했습니다.
|
| -------------------------------------------- |
|
|
수신자의 메일 보관 용량이 가득차 있습니다. 나중에 다시 시도하십시오.
|
|
| -------------------------------------------- |
|
--- Begin Message ---
On Wed, Jan 30, 2002 at 06:21:20PM +0000, peaw peaw wrote:
> Hello.
> I'm new to this mailing list :+)
>
> I created a mutilple-column index, say
>
> "create index col1_col2 on table_name (col1,col2) "
>
> Both col1 and col2 are mediumint unsigned.
>
> "explain select * from table_name where col1='value'
> order by col1 DESC,col2 DESC "
>
> shows that the query is still using filesort ! This is not supposed
> the be the case. Mysql manual says it should read the index
> backward.
That was added in MySQL 4.0.
--
Jeremy D. Zawodny, <[EMAIL PROTECTED]>
Technical Yahoo - Yahoo Finance
Desk: (408) 349-7878 Fax: (408) 349-5454 Cell: (408) 685-5936
MySQL 3.23.41-max: up 27 days, processed 615,862,667 queries (255/sec. avg)
---------------------------------------------------------------------
Before posting, please check:
http://www.mysql.com/manual.php (the manual)
http://lists.mysql.com/ (the list archive)
To request this thread, e-mail <[EMAIL PROTECTED]>
To unsubscribe, e-mail <[EMAIL PROTECTED]>
Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
--- End Message ---
---------------------------------------------------------------------
Before posting, please check:
http://www.mysql.com/manual.php (the manual)
http://lists.mysql.com/ (the list archive)
To request this thread, e-mail <[EMAIL PROTECTED]>
To unsubscribe, e-mail <[EMAIL PROTECTED]>
Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
