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From:gerald_clark Date:January 16 2003 8:12pm
Subject:Re: Avg_row_length
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It looks to me like 1 bit for deleted, and 1 bit for each column to 
store NULL.
1 byte for 1-7 fields.
2 bytes for 8-15 fields.

Stefan Hinz wrote:

>Keith,
>
>thanks once again! Well, anyone here from the MySQL developer team? Or
>any other guru who can explain why 10 = 11?
>
>Here's the problem once again:
>
>mysql> DESCRIBE myrowisam;
>+-------+----------+------+-----+---------+-------+
>| Field | Type     | Null | Key | Default | Extra |
>+-------+----------+------+-----+---------+-------+
>| col   | char(10) | YES  | MUL | NULL    |       |
>+-------+----------+------+-----+---------+-------+
>mysql> SHOW TABLE STATUS LIKE 'myrowisam';
>+-----------+--------+------------+------+----------------+
>| Name      | Type   | Row_format | Rows | Avg_row_length |
>+-----------+--------+------------+------+----------------+
>| myrowisam | MyISAM | Fixed      |  109 |             11 |
>+-----------+--------+------------+------+----------------+
>
>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: "Keith C. Ivey" <keith@stripped>
>To: <mysql@stripped>
>Cc: "Stefan Hinz" <hinz@stripped>
>Sent: Thursday, January 16, 2003 5:05 PM
>Subject: Re: Avg_row_length
>
>
>  
>
>>On 16 Jan 2003, at 0:37, Stefan Hinz wrote:
>>
>>    
>>
>>>>There's a formula to calculate the row length for dynamic MyISAM
>>>>tables here:
>>>>   http://www.mysql.com/doc/en/Dynamic_format.html
>>>>        
>>>>
>>>Thanks for the hint, but this doesn't explain fixed length row
>>>calculations where char(10) will give an average row length of 11
>>>(bytes), or does it?
>>>      
>>>
>>You're right, it doesn't.  I forgot that you were talking about fixed-
>>length records.  I'm afraid I don't have anything else to add then,
>>since I know nothing about the storage format other than what I've
>>seen in the documentation.
>>
>>[Filter fodder: SQL]
>>
>>--
>>Keith C. Ivey <keith@stripped>
>>Tobacco Documents Online
>>http://tobaccodocuments.org
>>Phone 202-667-6653
>>    
>>
>
>
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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