Neohapsis is currently accepting applications for employment. For more information, please visit our website www.neohapsis.com or email email@example.com
From: Jake Maul (jakemaulgmail.com)
Date: Fri Oct 31 2008 - 10:45:07 CDT
The maximum size of the temporary file that MySQL is allowed to use
while re-creating a MyISAM index (during REPAIR TABLE, ALTER TABLE, or
LOAD DATA INFILE). If the file size would be larger than this value,
the index is created using the key cache instead, which is slower. The
value is given in bytes. The default value is 2GB. If MyISAM index
files exceed this size and disk space is available, increasing the
value may help performance.
The size of the buffer that is allocated when sorting MyISAM indexes
during a REPAIR TABLE or when creating indexes with CREATE INDEX or
ALTER TABLE. The maximum allowable setting for myisam_sort_buffer_size
is 4GB. (Default is 8MB)
Simply: one's a buffer, one's a limit on the temp file size used for
sorting. Which you might need to increase depends entirely on which
limitation you're running into... if the current index files for the
relevant tables on disk exceed 2GB, you might want to increase
myisam_max_sort_file_size. Otherwise, myisam_sort_buffer_size might be
On Fri, Oct 31, 2008 at 12:20 AM, Moon's Father
> Because alter table and repair table are both affected by
> myisam_sort_buffer_size or myisam_max_sort_file_size, I'm in confusion then.
> Anybody can tell me which to be adjusted when I want to improve the
> performance of my index operation.
> I'm a MySQL DBA in china.
> More about me just visit here:
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql