* DeRyl
> * Roger Baklund
> The first thing to notice: "Using temporary"... this is to be avoided, if
> possible.
>
> ## how is the correct way to avoid that?
Depends, in this case I think it is because of the DISTINCT.
> The first table read is klientslowo based on the criteria
> klientslowo.kli
"DeRyl" <[EMAIL PROTECTED]> wrote on 09/23/2004 09:51:45 AM:
> The fact that you are joining 10 tables together in one query may be a
> major portion of your performance problem. Even if the *average* size of
> each table is only 10 rows, the MySQL engine will have to pour over
> 10x10x10x10x10x10
The fact that you are joining 10 tables together in one query may be a
major portion of your performance problem. Even if the *average* size of
each table is only 10 rows, the MySQL engine will have to pour over
10x10x10x10x10x10x10x10x10x10 = 10 to the 10th power = 1e10 =
10,000,000,000 (10 b
The first thing to notice: "Using temporary"... this is to be avoided, if
possible.
## how is the correct way to avoid that?
The first table read is klientslowo based on the criteria
klientslowo.klientslowo LIKE 'sam%'. Is this a reasonable approach to
solving the query, giving your knowledge of
* DeRyl
> explain example sql question gives:
[...]
The first thing to notice: "Using temporary"... this is to be avoided, if
possible.
The first table read is klientslowo based on the criteria
klientslowo.klientslowo LIKE 'sam%'. Is this a reasonable approach to
solving the query, giving your kn
Am Thursday 23 September 2004 13:22 schrieb Stefan Kuhn:
> This is probably due to having indexed only single columns. MySQL uses only
> one index per column, meaning if you have a where with two conditions you
Sorry, this should read "one index per table"...
> need a combined index for the colum
entulicaid` int(11) default NULL,
KEY `klientulicaid` (`klientulicaid`),
KEY `klientid` (`klientid`)
) TYPE=MyISAM;
---
Darek
- Original Message -
From: "Roger Baklund" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Cc: "DeRyl" <[EMAIL PROTECTED]>
Sen
This is probably due to having indexed only single columns. MySQL uses only
one index per column, meaning if you have a where with two conditions you
need a combined index for the columns used. If there are only indeces for the
single columns, only one index for one condition will be used, the r
* DeRyl
> I have database with 30 tables [some have over 2000k some other
> over 4000k rec]
>
> when I want to run a sql with a few conditions the answer is
> dramatically slow
> [over 70 seconds!]
> sql-s with one condition usually works well..
>
> how is the corrcet way to optimize the database
