> bit difficult to understand at first but it is
> fast.
> > > Remember to fetch 100
> > > to 1000 rows at a time. You don't want to fetch
> just
> > > 1 row from each call.
> > >
> > > Mike
> > >
> > &g
y sure that what the manual
> > > says is that MySQL only
> > > USES one index per request, not one index per
> table.
> > > I would try adding an
> > > index that starts with ColC (and maybe only
> ColC).
> > > Your index starts with
> > &
tty sure that what the manual
> > > says is that MySQL only
> > > USES one index per request, not one index per
> table.
> > > I would try adding an
> > > index that starts with ColC (and maybe only
> ColC).
> > > Your index starts with
> &
e
> MySQL decide to use no
> index in some situations. Mike
>
>
> - Original Message -----
> From: "Homam S.A." <[EMAIL PROTECTED]>
> To:
> Sent: February 22, 2005 8:12 PM
> Subject: Avoiding filesort #2
>
>
> > Actually with the qu
nal Message -
> From: "Homam S.A." <[EMAIL PROTECTED]>
> To:
> Sent: February 22, 2005 8:12 PM
> Subject: Avoiding filesort #2
>
>
> > Actually with the query below it does avoid
> filesort,
> > but once I use anything other than the equal
> operat
. This
could confuse the index selection process and have MySQL decide to use no
index in some situations. Mike
- Original Message -
From: "Homam S.A." <[EMAIL PROTECTED]>
To:
Sent: February 22, 2005 8:12 PM
Subject: Avoiding filesort #2
> Actually with the query
- Original Message -
From: "Homam S.A." <[EMAIL PROTECTED]>
To:
Sent: February 22, 2005 8:12 PM
Subject: Avoiding filesort #2
> Actually with the query below it does avoid filesort,
> but once I use anything other than the equal operator
> (e.g. ColC > 5),
Actually with the query below it does avoid filesort,
but once I use anything other than the equal operator
(e.g. ColC > 5), it reverts back to filesort.
Any thoughts?
--- "Homam S.A." <[EMAIL PROTECTED]> wrote:
> I read "How My SQL Optimizes Order By"
>
(http://dev.mysql.com/doc/mysql/en/orde
I read "How My SQL Optimizes Order By"
(http://dev.mysql.com/doc/mysql/en/order-by-optimization.html),
and I'm aware of its severe limitation due to the
one-index-per-table rule.
However, even when I follow all the roles, I'm still
getting filesort instead of using the index order.
So I created a
