The following system variables affect the behavior of
MyISAM tables. For additional information,
see Section 5.1.3, “Server System Variables”.
The size of the tree cache used in bulk insert optimization.
This is a limit per thread!
Used to help MySQL to decide when to use the slow but safe key cache index creation method.
This parameter is given in megabytes before MySQL 4.0.3, and in bytes as of 4.0.3.
The maximum size of the temporary file that MySQL is
permitted to use while re-creating a
MyISAM index (during
ALTER TABLE, or
INFILE). If the file size would be larger than
this value, the index is created using the key cache
instead, which is slower. This variable was added in MySQL
The value is given in megabytes before 4.0.3 and in bytes thereafter.
Set the size of the buffer used when recovering tables.
Automatic recovery is activated if you start
mysqld with the
--myisam-recover option. In this
case, when the server opens a
it checks whether the table is marked as crashed or whether the
open count variable for the table is not 0 and you are running
the server with external locking disabled. If either of these
conditions is true, the following happens:
The server checks the table for errors.
If the server finds an error, it tries to do a fast table repair (with sorting and without re-creating the data file).
If the repair fails because of an error in the data file (for example, a duplicate-key error), the server tries again, this time re-creating the data file.
If the repair still fails, the server tries once more with the old repair option method (write row by row without sorting). This method should be able to repair any type of error and has low disk space requirements.
If the recovery wouldn't be able to recover all rows from
previously completed statements and you didn't specify
FORCE in the value of the
automatic repair aborts with an error message in the error log:
Error: Couldn't repair table: test.g00pages
If you specify
FORCE, a warning like this is
Warning: Found 344 of 354 rows when repairing ./test/g00pages
Note that if the automatic recovery value includes
BACKUP, the recovery process creates files
with names of the form
You should have a cron script that
automatically moves these files from the database directories to