But why doesn't this work then:
select name, tottid, distance, min(mintid) from loeb group by distance;
(tottid seems to be random)
mysql> explain select name, tottid, distance, min(mintid) from loeb group by
distance;
+-------+------+---------------+------+---------+------+------+-------+
| table | type | possible_keys | key | key_len | ref | rows | Extra |
+-------+------+---------------+------+---------+------+------+-------+
| loeb | ALL | NULL | NULL | NULL | NULL | 90 | |
+-------+------+---------------+------+---------+------+------+-------+
1 row in set (0.00 sec)
// Chris
> -----Oprindelig meddelelse-----
> Fra: Thalis A. Kalfigopoulos [SMTP:[EMAIL PROTECTED]]
> Sendt: 30. april 2001 15:42
> Til: Wix,Christian XCW
> Cc: '[EMAIL PROTECTED]'
> Emne: Re: index troubles
>
> Hello,
>
> The index you have created is just fine and should be utilized as long as
> you perform a query that needs to use an index.
> Your query:
> select a,b from t;
> doesn't have any conditions imposed upon the table's rows. It just asks
> for all the them. Simple file scan.
>
> regards,
> thalis
>
>
> On Mon, 30 Apr 2001, Wix,Christian XCW wrote:
>
> > Hi!
> > I have some troubles with my index.
> > I want to be able to use an index (test=(mintid, name)). I will use the
> > index when I write: select mintid, name from loeb;
> > I have created an index but it doesn't seem to work. Why?
> > // Chris - Copenhagen
> >
> > mysql> show index from loeb;
> >
> +-------+------------+----------+--------------+-------------+-----------+
> --
> > -----------+----------+
> > | Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation
> |
> > Cardinality | Sub_part |
> >
> +-------+------------+----------+--------------+-------------+-----------+
> --
> > -----------+----------+
> > | loeb | 0 | PRIMARY | 1 | id | A
> |
> > 90 | NULL |
> > | loeb | 1 | rekord | 1 | mintid | A
> |
> > NULL | NULL |
> > | loeb | 1 | test | 1 | mintid | A
> |
> > NULL | NULL |
> > | loeb | 1 | test | 2 | name | A
> |
> > NULL | NULL |
> >
> +-------+------------+----------+--------------+-------------+-----------+
> --
> > -----------+----------+
> > 4 rows in set (0.00 sec)
> >
> > mysql> show columns from loeb;
> > +----------+-------------+------+-----+----------+----------------+
> > | Field | Type | Null | Key | Default | Extra |
> > +----------+-------------+------+-----+----------+----------------+
> > | name | varchar(20) | | | | |
> > | distance | double(3,1) | | | 0.0 | |
> > | dato | date | YES | | NULL | |
> > | id | int(11) | | PRI | 0 | auto_increment |
> > | tottid | time | | | 00:00:00 | |
> > | mintid | time | | MUL | 00:00:00 | |
> > | art | varchar(10) | YES | | NULL | |
> > +----------+-------------+------+-----+----------+----------------+
> > 7 rows in set (0.00 sec)
> >
> > mysql> explain select mintid, name from loeb;
> > +-------+------+---------------+------+---------+------+------+-------+
> > | table | type | possible_keys | key | key_len | ref | rows | Extra |
> > +-------+------+---------------+------+---------+------+------+-------+
> > | loeb | ALL | NULL | NULL | NULL | NULL | 90 | |
> > +-------+------+---------------+------+---------+------+------+-------+
> > 1 row in set (0.00 sec)
> >
> >
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