Thanks for your patient replay.
This means the myisam_max_sort_file_size is the limitation of
myisam_sort_buffer_size.
And they are both implemented to improve the DDL statements.
On Fri, Oct 31, 2008 at 11:45 PM, Jake Maul [EMAIL PROTECTED] wrote:
From dev.mysql.com:
myisam_max_sort_file_size :
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.
myisam_sort_buffer_size:
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
better.
Jake
On Fri, Oct 31, 2008 at 12:20 AM, Moon's Father
[EMAIL PROTECTED] wrote:
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.
Thanks.
--
I'm a MySQL DBA in china.
More about me just visit here:
http://yueliangdao0608.cublog.cn
--
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe:
http://lists.mysql.com/[EMAIL PROTECTED]
--
I'm a MySQL DBA in china.
More about me just visit here:
http://yueliangdao0608.cublog.cn
