上面的两个命令都可以执行对指定表的检查。要检查数据库中所有的表,可以使用通配符:
% myisamchk /usr/local/mysql/var/dbName/*.MYI
要检查所有数据库中的所有表,可以使用两个通配符:
% myisamchk /usr/local/mysql/var/*/*.MYI
如果不带任何选项,myisamchk将对表文件执行普通的检查。如果你对一个表有怀疑,但是普通的检查不能发现任何错误,你可以执行更彻底的检查(但是也更慢!),这需要使用--extend-check选项:
% myisamchk --extend-check /path/to/tblName
对错误的检查是没有破坏性的,这意味着你不必担心执行对你的数据文件的检查会使已经存在的问题变得更糟。另一方面,修复选项,虽然通常也是安全的,但是它对你的数据文件的更改是无法撤消的。因为这个原因,我们强烈推荐你试图修复一个被破坏的表文件时首先做个备份,并确保在制作这个备份之前你的MySQL服务是关闭的。
我在win2003下通过命令提示符,输入:
注:此为记录我当时操作的全部过程
Documents and SettingsAdministrator>c:
C:>cd mysql
C:mysql>cd data
C:mysqldata>cd hw_enterprice
C:mysqldatahw_enterprice>myisamchk function_products.frm'myisamchk' 不是内部或外部命令,也不是可运行的程序
或批处理文件。
C:mysqldatahw_enterprice>cd
C:>cd mysql
C:mysql>cd bin
注:查看myisamchk的帮助信息
C:mysqlin>myisamchk
myisamchk Ver 2.6 for Win95/Win98 at i32
By Monty, for your professional use
This software comes with NO WARRANTY: see the PUBLIC for details.
Description, check and repair of ISAM tables.
Used without opti**** all tables on the command will be checked for errors
Usage: myisamchk [OPTI****] tables[.MYI]
Global opti****:
-#, --debug=... Output debug log. Often this is 'd:t,filename'
-?, --help Display this help and exit.
-O, --set-variable var=option
Change the value of a variable. Please note that
this option is deprecated; you can set variables
directly with '--variable-name=value'.
-t, --tmpdir=path Path for temporary files
-s, --silent Only print errors. One can use two -s to make
myisamchk very silent
-v, --verbose Print more information. This can be used with
--description and --check. Use many -v for more verbosity!
-V, --version Print version and exit.
-w, --wait Wait if table is locked.
Check opti**** (check is the default action for myisamchk):
-c, --check Check table for errors
-e, --extend-check Check the table VERY throughly. Only use this in
extreme cases as myisamchk should normally be able to
find out if the table is ok even without this switch
-F, --fast Check only tables that haven't been closed properly
-C, --check-only-changed
Check only tables that have changed since last check
-f, --force Restart with '-r' if there are any errors in the table.
States will be updated as with '--update-state'
-i, --information Print statistics information about table that is checked
-m, --medium-check Faster than extend-check, but only finds 99.99% of
all errors. Should be good enough for most cases
-U --update-state Mark tables as crashed if you find any errors
-T, --read-only Don't mark table as checked
Repair opti**** (When using '-r' or '-o')
-B, --backup Make a backup of the .MYD file as 'filename-time.BAK'
--correct-checksum Correct checksum information for table.
-D, --data-file-length=# Max length of data file (when recreating data
file when it's full)
-e, --extend-check Try to recover every possible row from the data file
Normally this will also find a lot of garbage rows;
Don't use this option if you are not totally desperate.
-f, --force Overwrite old temporary files.
-k, --keys-used=# Tell MyISAM to update only some specific keys. # is a
bit mask of which keys to use. This can be used to
get faster inserts!
-r, --recover Can fix almost anything except unique keys that aren't
unique.
-n, --sort-recover Forces recovering with sorting even if the temporary
file would be very big.
-p, --parallel-recover
Uses the same technique as '-r' and '-n', but creates
all the keys in parallel, in different threads.
THIS IS ALPHA CODE. USE AT YOUR OWN RISK!
-o, --safe-recover Uses old recovery method; Slower than '-r' but can
handle a couple of cases where '-r' reports that it
can't fix the data file.
--character-sets-dir=...
Directory where character sets are
--set-character-set=name
Change the character set used by the index
-q, --quick Faster repair by not modifying the data file.
One can give a second '-q' to force myisamchk to
modify the original datafile in case of duplicate keys
-u, --unpack Unpack file packed with myisampack.
Other acti****:
-a, --analyze Analyze distribution of keys. Will make some joins in
MySQL faster. You can check the calculated distribution
by using '--description --verbose table_name'.
-d, --description Prints some information about table.
-A, --set-auto-increment[=value]
Force auto_increment to start at this or higher value
If no value is given, then sets the next auto_increment
value to the highest used value for the auto key + 1.
-S, --sort-index Sort index blocks. This speeds up 'read-next' in
applicati****
-R, --sort-records=#
Sort records according to an index. This makes your
data much more localized and may speed up things
C:mysqlin>myisamchk c:mysqldatahw_enterpricefunction_products.frm
myisamchk: error: 'c:mysqldatahw_enterpricefunction_products.frm' is not a M
yISAM-table
C:mysqlin>myisamchk c:mysqldatahw_enterpricefunction_products.myi
Checking MyISAM file: c:mysqldatahw_enterpricefunction_products.myi
Data records: 85207 Deleted blocks: 39
myisamchk: warning: Table is marked as crashed
myisamchk: warning: 1 clients is using or hasn't closed the table properly
- check file-size
- check key delete-chain
- check record delete-chain
myisamchk: error: record delete-link-chain corrupted
- check index reference
- check data record references index: 1
- check data record references index: 2
- check data record references index: 3
- check record links
myisamchk: error: Wrong bytesec: 0-195-171 at linkstart: 841908
MyISAM-table 'c:mysqldatahw_enterpricefunction_products.myi' is corrupted
Fix it using switch "-r" or "-o"
继续进行操作:
C:mysqlin>myisamchk --recover --quick c:mysqldatahw_enterpricefunction_p
roducts.myi
- check key delete-chain
- check record delete-chain
myisamchk: error: record delete-link-chain corrupted
myisamchk: error: Quick-recover aborted; Run recovery without switch 'q'
Updating MyISAM file: c:mysqldatahw_enterpricefunction_products.myi
MyISAM-table 'c:mysqldatahw_enterpricefunction_products.myi' is not fixed be
cause of errors
Try fixing it by using the --safe-recover (-o) or the --force (-f) option
系统提示我使用--safe-recover (-o) or the --force (-f) option进行修复操作,于是
C:mysqlin>myisamchk --safe-recover c:mysqldatahw_enterpricefunction_prod
ucts.myi
- recovering (with keycache) MyISAM-table 'c:mysqldatahw_enterpricefunction_
products.myi'
Data records: 85207
Wrong bytesec: 0-195-171 at 841908; Skipped
Data records: 85215
将修复后的物理文件复制到mysqldata下之后,通过phpMyAdmin进行访问,OK正常!
本次数据修复操作成功,数据已被正常恢复,总计85215条记录,其中恢复数据共计85207条。
总结本次经验及查找资料,如下: