MySQL数据库中部分数据损坏恢复过程

注：此为记录我当时操作的全部过程

d:\documents and settings\administrator>c:

c:\>cd MySQL

c:\mysql>cd data

c:\mysql\data>cd hw_enterprice

c:\mysql\data\hw_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:\mysql\data\hw_enterprice>cd\

c:\>cd mysql

c:\mysql>cd bin

注：查看myisamchk的帮助信息

c:\mysql\bin>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 options all tables on the command will be checked for errors

usage: myisamchk [options] tables[.myi]
global options:

-#, --debug=...     output debug log. often this is 'd:t:o,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 options (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 options (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 actions:

-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

applications

-r, --sort-records=#

sort records according to an index.  this makes your

data much more localized and may speed up things

c:\mysql\bin>myisamchk c:\mysql\data\hw_enterprice\function_products.frm

myisamchk: error: 'c:\mysql\data\hw_enterprice\function_products.frm' is not a m

yisam-table
c:\mysql\bin>myisamchk c:\mysql\data\hw_enterprice\function_products.myi

checking myisam file: c:\mysql\data\hw_enterprice\function_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:\MySQL\data\hw_enterprice\function_products.myi' is corrupted

fix it using switch "-r" or "-o"