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From:Stefan Hinz Date:January 15 2003 12:05pm
Subject:Re: Avg_row_length
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Dan,

>  * Each `NULL' column takes one bit extra, rounded up to the nearest
>    byte.

This is what Jennifer and Steve said. Well, here's the counter evidence:

mysql> DESCRIBE mynotnullisam;
+-------+----------+------+-----+---------+-------+
| Field | Type     | Null | Key | Default | Extra |
+-------+----------+------+-----+---------+-------+
| col   | char(10) |      |     |         |       |
+-------+----------+------+-----+---------+-------+
1 row in set (0.16 sec)

mysql> SHOW TABLE STATUS LIKE 'mynotnullisam';
+---------------+--------+------------+------+----------------+---------
----+
| Name          | Type   | Row_format | Rows | Avg_row_length |
Data_length |
+---------------+--------+------------+------+----------------+---------
----+
| mynotnullisam | MyISAM | Fixed      |    3 |             11 |
33 |
+---------------+--------+------------+------+----------------+---------
----+

Regards,
--
  Stefan Hinz <hinz@stripped>
  Geschäftsführer / CEO iConnect GmbH <http://iConnect.de>
  Heesestr. 6, 12169 Berlin (Germany)
  Tel: +49 30 7970948-0  Fax: +49 30 7970948-3

----- Original Message -----
From: "Dan Nelson" <dnelson@stripped>
To: "Stefan Hinz" <hinz@stripped>
Cc: <mysql@stripped>
Sent: Wednesday, January 15, 2003 1:22 AM
Subject: Re: Avg_row_length


> In the last episode (Jan 14), Stefan Hinz said:
> > here's my final stupid question for today. Why is the average row
> > length 11 when it should be 10?
> >
> > mysql> DESCRIBE myrowisam;
> > +-------+----------+------+-----+---------+-------+
> > | Field | Type     | Null | Key | Default | Extra |
> > +-------+----------+------+-----+---------+-------+
> > | col   | char(10) | YES  |     | NULL    |       |
> > +-------+----------+------+-----+---------+-------+
> >
> > mysql> SHOW TABLE STATUS LIKE 'myrow%';
> > +-------------+--------+------------+------+----------------+
> > | Name        | Type   | Row_format | Rows | Avg_row_length |
> > +-------------+--------+------------+------+----------------+
> > | myrowisam   | MyISAM | Fixed      |   68 |             11 | <---
>
>  * Each `NULL' column takes one bit extra, rounded up to the nearest
>    byte.
>
>
> --
> Dan Nelson
> dnelson@stripped

Thread
Avg_row_lengthStefan Hinz14 Jan
  • RE: Avg_row_lengthJennifer Goodie15 Jan
  • Re: Avg_row_lengthSteve Edberg15 Jan
  • Re: Avg_row_lengthDan Nelson15 Jan
  • Re: Avg_row_lengthStefan Hinz15 Jan
    • Re: Avg_row_lengthSteve Edberg15 Jan
    • Re: Avg_row_lengthKeith C. Ivey15 Jan
      • Re: Avg_row_lengthStefan Hinz16 Jan
        • Re: Avg_row_lengthKeith C. Ivey16 Jan
          • Re: Avg_row_lengthStefan Hinz16 Jan
            • Re: Avg_row_lengthSergei Golubchik16 Jan
            • Re: Avg_row_lengthZak Greant16 Jan
          • Re: Avg_row_lengthgerald_clark16 Jan
          • Re: Avg_row_lengthStefan Hinz16 Jan
            • Re: Avg_row_lengthSergei Golubchik17 Jan
            • Re: Avg_row_lengthRoger Baklund17 Jan
          • Re: Avg_row_lengthgerald_clark17 Jan
          • Re: Avg_row_lengthStefan Hinz17 Jan
  • Re: Avg_row_lengthStefan Hinz15 Jan
  • Re: Avg_row_lengthStefan Hinz15 Jan