When this limit will be removed ?
from 5.1 manual (13.1.4)
"An index_col_name specification can end with ASC or DESC. These keywords are
allowed for future extensions for specifying ascending or descending index
value storage. Currently they are parsed but ignored; index values are a
One trick I have used in the past in other databases is to
create your own descending index. If your field is say fieldA, when
you enter a row into the table take the value of fieldA and subtract
from 0, then put that in fieldB. Index fieldB and you now can order
rows descending
ostly never used), and very weird if ascending index used for
descending query. I'm not talking about returning correct result set
(either order by desc, limit, etc), but avoid table scan.
This is my first serious mysql application, as usually i'm using
Interbase where
your explain seems normal for me.
Regards,
Jocelyn
- Original Message -
From: "Mpu Gondrong" <[EMAIL PROTECTED]>
To: "Jeremy Zawodny" <[EMAIL PROTECTED]>
Sent: Tuesday, December 17, 2002 1:13 AM
Subject: Re[2]: No descending index ?
> Selasa, 17/12/2
Selasa, 17/12/2002 7:47:38, Jeremy menulis:
JZ> I'm not quite sure what you're after, but MySQL 4.0 has support
JZ> for reading indexes in reverse order in some circumstances. This
JZ> greatly speeds up some queries that were slow in 3.23.
I'm using MySQL 4.0.4-beta. For example:
EXPLAIN SE
Mpu Gondrong wrote:
Selasa, 17/12/2002 7:38:52, Daniel menulis:
DK> What's wrong with using: order by MyIndex DESC
If I have 100 rows and mysql calculates with desc got 90 or more
(>30%) rows, index won't be used. I have thousand rows, and just want
to get the last row. Without index, th
On Tue, Dec 17, 2002 at 07:37:17AM +0700, Mpu Gondrong wrote:
> Hello mysql,
>
> I am currently building news portal with php and mysql, and quite
> surprised knowing mysql doesn't support descending index. Why ? I
> think this feature is really needed. For exampl
Mpu Gondrong wrote:
Hello mysql,
I am currently building news portal with php and mysql, and quite
surprised knowing mysql doesn't support descending index. Why ? I
think this feature is really needed. For example I want to show the
latest news (from last updates, not a
Hi,
Can you just
SELECT x, y, z FROM table WHERE ORDER BY timestamp_column
DESC;
?
-Dan
On Tue, 17 Dec 2002, Mpu Gondrong wrote:
> Hello mysql,
>
> I am currently building news portal with php and mysql, and quite
> surprised knowing mysql doesn't support desc
Hello mysql,
I am currently building news portal with php and mysql, and quite
surprised knowing mysql doesn't support descending index. Why ? I
think this feature is really needed. For example I want to show the
latest news (from last updates, not always everyday). With asce
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