mysql数据库下损坏数据的恢复操作其过程总结

<p>C:\mysql\bin>myisamchk<br>myisamchk Ver 2.6 for Win95/Win98 at i32<br>By Monty, for your professional use<br>This software comes with NO WARRANTY: see the PUBLIC for details.</p><p>Description, check and repair of ISAM tables.<br>Used without options all tables on the command will be checked for errors<br>Usage: myisamchk [OPTIONS] tables[.MYI]</p><p>Global options:<br>-#, –debug=… Output debug log. Often this is ‘d:t:o,filename’<br>-?, –help Display this help and exit.<br>-O, –set-variable var=option<br>Change the value of a variable. Please note that<br>this option is deprecated; you can set variables<br>directly with ‘–variable-name=value’.<br>-t, –tmpdir=path Path for temporary files<br>-s, –silent Only print errors. One can use two -s to make<br>myisamchk very silent<br>-v, –verbose Print more information. This can be used with<br>–description and –check. Use many -v for more verbosity!</p><p>-V, –version Print version and exit.<br>-w, –wait Wait if table is locked.</p><p>Check options (check is the default action for myisamchk):<br>-c, –check Check table for errors<br>-e, –extend-check Check the table VERY throughly. Only use this in<br>extreme cases as myisamchk should normally be able to<br>find out if the table is ok even without this switch<br>-F, –fast Check only tables that haven’t been closed properly<br>-C, –check-only-changed<br>Check only tables that have changed since last check<br>-f, –force Restart with ‘-r’ if there are any errors in the table.<br>States will be updated as with ‘–update-state’<br>-i, –information Print statistics information about table that is checked<br>-m, –medium-check Faster than extend-check, but only finds 99.99% of<br>all errors. Should be good enough for most cases<br>-U –update-state Mark tables as crashed if you find any errors<br>-T, –read-only Don’t mark table as checked</p><p>Repair options (When using ‘-r’ or ‘-o’)<br>-B, –backup Make a backup of the .MYD file as ‘filename-time.BAK’<br>–correct-checksum Correct checksum information for table.<br>-D, –data-file-length=# Max length of data file (when recreating data<br>file when it’s full)<br>-e, –extend-check Try to recover every possible row from the data file<br>Normally this will also find a lot of garbage rows;<br>Don’t use this option if you are not totally desperate.<br>-f, –force Overwrite old temporary files.<br>-k, –keys-used=# Tell MyISAM to update only some specific keys. # is a<br>bit mask of which keys to use. This can be used to<br>get faster inserts!<br>-r, –recover Can fix almost anything except unique keys that aren’t<br>unique.<br>-n, –sort-recover Forces recovering with sorting even if the temporary<br>file would be very big.<br>-p, –parallel-recover<br>Uses the same technique as ‘-r’ and ‘-n’, but creates<br>all the keys in parallel, in different threads.<br>THIS IS ALPHA CODE. USE AT YOUR OWN RISK!<br>-o, –safe-recover Uses old recovery method; Slower than ‘-r’ but can<br>handle a couple of cases where ‘-r’ reports that it<br>can’t fix the data file.<br>–character-sets-dir=…<br>Directory where character sets are<br>–set-character-set=name<br>Change the character set used by the index<br>-q, –quick Faster repair by not modifying the data file.<br>One can give a second ‘-q’ to force myisamchk to<br>modify the original datafile in case of duplicate keys<br>-u, –unpack Unpack file packed with myisampack.</p><p>Other actions:<br>-a, –analyze Analyze distribution of keys. Will make some joins in<br>MySQL faster. You can check the calculated distribution<br>by using ‘–description –verbose table_name’.<br>-d, –description Prints some information about table.<br>-A, –set-auto-increment[=value]<br>Force auto_increment to start at this or higher value<br>If no value is given, then sets the next auto_increment<br>value to the highest used value for the auto key + 1.<br>-S, –sort-index Sort index blocks. This speeds up ‘read-next’ in<br>applications<br>-R, –sort-records=#<br>Sort records according to an index. This makes your<br>data much more localized and may speed up things<br>C:\mysql\bin>myisamchk c:\mysql\data\hw_enterprice\function_products.frm<br>myisamchk: error: ‘c:\mysql\data\hw_enterprice\function_products.frm’ is not a M<br>yISAM-table</p><p>C:\mysql\bin>myisamchk c:\mysql\data\hw_enterprice\function_products.myi<br>Checking MyISAM file: c:\mysql\data\hw_enterprice\function_products.myi<br>Data records: 85207 Deleted blocks: 39<br>myisamchk: warning: Table is marked as crashed<br>myisamchk: warning: 1 clients is using or hasn’t closed the table properly<br>- check file-size<br>- check key delete-chain<br>- check record delete-chain<br>myisamchk: error: record delete-link-chain corrupted<br>- check index reference<br>- check data record references index: 1<br>- check data record references index: 2<br>- check data record references index: 3<br>- check record links<br>myisamchk: error: Wrong bytesec: 0-195-171 at linkstart: 841908<br>MyISAM-table ‘c:\mysql\data\hw_enterprice\function_products.myi’ is corrupted<br>Fix it using switch “-r” or “-o”</p><p>继续进行操作：</p><p>C:\mysql\bin>myisamchk –recover –quick c:\mysql\data\hw_enterprice\function_p<br>roducts.myi<br>- check key delete-chain<br>- check record delete-chain<br>myisamchk: error: record delete-link-chain corrupted<br>myisamchk: error: Quick-recover aborted; Run recovery without switch ‘q’<br>Updating MyISAM file: c:\mysql\data\hw_enterprice\function_products.myi<br>MyISAM-table ‘c:\mysql\data\hw_enterprice\function_products.myi’ is not fixed be<br>cause of errors<br>Try fixing it by using the –safe-recover (-o) or the –force (-f) option</p><p>系统提示我使用–safe-recover (-o) or the –force (-f) option进行修复操作，于是</p><p>C:\mysql\bin>myisamchk –safe-recover c:\mysql\data\hw_enterprice\function_prod<br>ucts.myi<br>- recovering (with keycache) MyISAM-table ‘c:\mysql\data\hw_enterprice\function_<br>products.myi’<br>Data records: 85207<br>Wrong bytesec: 0-195-171 at 841908; Skipped<br>Data records: 85215</p>