Gerald, > >>(in fact it's a bitmap, that is it would be one byte for up to 8 > >>columns, then it'll be 2 bytes, etc.)
> >If so, this table should have an average row length of 92, not 91, > It does on mine. Alright, I take this as a Windows goodie (my MySQL 4.0.7 runs on Win2K ;-) Regards, -- Stefan Hinz <[EMAIL PROTECTED]> 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: "gerald_clark" <[EMAIL PROTECTED]> To: "Stefan Hinz" <[EMAIL PROTECTED]> Cc: "Sergei Golubchik" <[EMAIL PROTECTED]>; "Keith C. Ivey" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Friday, January 17, 2003 3:48 PM Subject: Re: Avg_row_length > > > Stefan Hinz wrote: > > >Sergei, > > > > > > > >>>any other guru who can explain why 10 = 11? > >>> > >>> > > > > > > > >>It's because of NULLs. > >>Extra byte is used to mark, if the column is NULL or not. > >> > >> > > > >Thanks alot for the explanation. Thanks to Gerald Clark, too, who told > >me the same. > > > > > > > >>(in fact it's a bitmap, that is it would be one byte for up to 8 > >>columns, then it'll be 2 bytes, etc.) > >> > >> > > > >If so, this table should have an average row length of 92, not 91, > > > > It does on mine. > > >shouldn't it (9 cols * 10 bytes + 2 bytes)? > > > >MySQL>DESCRIBE myrowisam; > >+-------+----------+------+-----+---------+-------+ > >| Field | Type | Null | Key | Default | Extra | > >+-------+----------+------+-----+---------+-------+ > >| col1 | char(10) | | | | | > >| col2 | char(10) | | | | | > >| col3 | char(10) | | | | | > >| col4 | char(10) | | | | | > >| col5 | char(10) | | | | | > >| col6 | char(10) | | | | | > >| col7 | char(10) | | | | | > >| col8 | char(10) | | | | | > >| col9 | char(10) | | | | | > >+-------+----------+------+-----+---------+-------+ > >MySQL>SELECT * FROM myrowisam; > >+------+------+------+------+------+------+------+------+------+ > >| col1 | col2 | col3 | col4 | col5 | col6 | col7 | col8 | col9 | > >+------+------+------+------+------+------+------+------+------+ > >| foo | foo | foo | foo | foo | foo | foo | foo | foo | > >+------+------+------+------+------+------+------+------+------+ > >MySQL>SHOW TABLE STATUS LIKE 'myrowisam'; > >+-----------+--------+------------+------+----------------+ > >| Name | Type | Row_format | Rows | Avg_row_length | > >+-----------+--------+------------+------+----------------+ > >| myrowisam | MyISAM | Fixed | 1 | 91 | > >+-----------+--------+------------+------+----------------+ > > > >Regards, > >-- > > Stefan Hinz <[EMAIL PROTECTED]> > > 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: "Sergei Golubchik" <[EMAIL PROTECTED]> > >To: "Stefan Hinz" <[EMAIL PROTECTED]> > >Cc: "Keith C. Ivey" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> > >Sent: Thursday, January 16, 2003 9:16 PM > >Subject: Re: Avg_row_length > > > > > > > > > >>Hi! > >> > >>On Jan 16, 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 <[EMAIL PROTECTED]> > >>> Gesch?ftsf?hrer / CEO iConnect GmbH <http://iConnect.de> > >>> Heesestr. 6, 12169 Berlin (Germany) > >>> Tel: +49 30 7970948-0 Fax: +49 30 7970948-3 > >>> > >>> > >>It's because of NULLs. > >>Extra byte is used to mark, if the column is NULL or not. > >> > >>(in fact it's a bitmap, that is it would be one byte for up to 8 > >>columns, then it'll be 2 bytes, etc.) > >> > >>Regards, > >>Sergei > >> > >>-- > >>MySQL Development Team > >> __ ___ ___ ____ __ > >> / |/ /_ __/ __/ __ \/ / Sergei Golubchik <[EMAIL PROTECTED]> > >> / /|_/ / // /\ \/ /_/ / /__ MySQL AB, http://www.mysql.com/ > >>/_/ /_/\_, /___/\___\_\___/ Osnabrueck, Germany > >> <___/ > >> > >> > > > > > > > > > > > > --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
