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 <[EMAIL PROTECTED]> Tobacco Documents Online http://tobaccodocuments.org Phone 202-667-6653 --------------------------------------------------------------------- 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
