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From:Stefan Hinz Date:January 15 2003 11:37pm
Subject:Re: Avg_row_length
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Keith,

> 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?

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: Wednesday, January 15, 2003 4:39 PM
Subject: Re: Avg_row_length


> On 15 Jan 2003, at 13:03, Stefan Hinz wrote:
>
> > > I believe there is an extra byte for the 'null' flag; if you
declare
> > > this column to be NOT NULL, I'll bet the avg length will be 10.
> >
> > nice bet, but you lose <g>:
>
> In addition to the bitmap for which columns have null values (if
> there are any columns that can be null), there's a similar bitmap to
> show which columns have zero values (or the empty string, for string
> columns).  That normally saves space because no additional storage is
> used if the column is zero.
>
> There's a formula to calculate the row length for dynamic MyISAM
> tables here:
>
>    http://www.mysql.com/doc/en/Dynamic_format.html
>
> --
> Keith C. Ivey <keith@stripped>
> Tobacco Documents Online
> http://tobaccodocuments.org
> Phone 202-667-6653

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