<div id="docs-body">
 <div class="section">
  <div class="titlepage">
   <div>
    <div>
     <h4 class="title">
      <a name="myisamchk-check-options">
      </a>
      6.6.4.2 myisamchk Check Options
     </h4>
    </div>
   </div>
  </div>
  <a class="indexterm" name="idm46045307240496">
  </a>
  <a class="indexterm" name="idm46045307239008">
  </a>
  <p>
   <a class="link" href="myisamchk.html" title="6.6.4 myisamchk — MyISAM Table-Maintenance Utility">
    <span class="command">
     <strong>
      myisamchk
     </strong>
    </span>
   </a>
   supports the following options for
        table checking operations:
  </p>
  <div class="itemizedlist">
   <ul class="itemizedlist" style="list-style-type: disc; ">
    <li class="listitem">
     <p>
      <a name="option_myisamchk_check">
      </a>
      <a class="link" href="myisamchk-check-options.html#option_myisamchk_check">
       <code class="option">
        --check
       </code>
      </a>
      ,
      <code class="option">
       -c
      </code>
     </p>
     <div class="informaltable">
      <table frame="box" rules="all" summary="Properties for check">
       <colgroup>
        <col style="width: 30%"/>
        <col style="width: 70%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Command-Line Format
         </th>
         <td>
          <code class="literal">
           --check
          </code>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <a class="indexterm" name="idm46045307227728">
     </a>
     <a class="indexterm" name="idm46045307226240">
     </a>
     <p>
      Check the table for errors. This is the default operation if
            you specify no option that selects an operation type
            explicitly.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="option_myisamchk_check-only-changed">
      </a>
      <a class="link" href="myisamchk-check-options.html#option_myisamchk_check-only-changed">
       <code class="option">
        --check-only-changed
       </code>
      </a>
      ,
      <code class="option">
       -C
      </code>
     </p>
     <div class="informaltable">
      <table frame="box" rules="all" summary="Properties for check-only-changed">
       <colgroup>
        <col style="width: 30%"/>
        <col style="width: 70%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Command-Line Format
         </th>
         <td>
          <code class="literal">
           --check-only-changed
          </code>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <a class="indexterm" name="idm46045307216048">
     </a>
     <a class="indexterm" name="idm46045307214544">
     </a>
     <p>
      Check only tables that have changed since the last check.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="option_myisamchk_extend-check">
      </a>
      <a class="link" href="myisamchk-check-options.html#option_myisamchk_extend-check">
       <code class="option">
        --extend-check
       </code>
      </a>
      ,
      <code class="option">
       -e
      </code>
     </p>
     <div class="informaltable">
      <table frame="box" rules="all" summary="Properties for extend-check">
       <colgroup>
        <col style="width: 30%"/>
        <col style="width: 70%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Command-Line Format
         </th>
         <td>
          <code class="literal">
           --extend-check
          </code>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <a class="indexterm" name="idm46045307204496">
     </a>
     <a class="indexterm" name="idm46045307203008">
     </a>
     <p>
      Check the table very thoroughly. This is quite slow if the
            table has many indexes. This option should only be used in
            extreme cases. Normally,
      <a class="link" href="myisamchk.html" title="6.6.4 myisamchk — MyISAM Table-Maintenance Utility">
       <span class="command">
        <strong>
         myisamchk
        </strong>
       </span>
      </a>
      or
      <a class="link" href="myisamchk.html" title="6.6.4 myisamchk — MyISAM Table-Maintenance Utility">
       <span class="command">
        <strong>
         myisamchk --medium-check
        </strong>
       </span>
      </a>
      should be able
            to determine whether there are any errors in the table.
     </p>
     <p>
      If you are using
      <a class="link" href="myisamchk-check-options.html#option_myisamchk_extend-check">
       <code class="option">
        --extend-check
       </code>
      </a>
      and have
            plenty of memory, setting the
      <code class="literal">
       key_buffer_size
      </code>
      variable to a large value
            helps the repair operation run faster.
     </p>
     <p>
      See also the description of this option under table repair
            options.
     </p>
     <p>
      For a description of the output format, see
      <a class="xref" href="myisamchk-table-info.html" title="6.6.4.5 Obtaining Table Information with myisamchk">
       Section 6.6.4.5, “Obtaining Table Information with myisamchk”
      </a>
      .
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="option_myisamchk_fast">
      </a>
      <a class="link" href="myisamchk-check-options.html#option_myisamchk_fast">
       <code class="option">
        --fast
       </code>
      </a>
      ,
      <code class="option">
       -F
      </code>
     </p>
     <div class="informaltable">
      <table frame="box" rules="all" summary="Properties for fast">
       <colgroup>
        <col style="width: 30%"/>
        <col style="width: 70%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Command-Line Format
         </th>
         <td>
          <code class="literal">
           --fast
          </code>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <a class="indexterm" name="idm46045307186240">
     </a>
     <a class="indexterm" name="idm46045307184752">
     </a>
     <p>
      Check only tables that haven't been closed properly.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="option_myisamchk_force">
      </a>
      <a class="link" href="myisamchk-check-options.html#option_myisamchk_force">
       <code class="option">
        --force
       </code>
      </a>
      ,
      <code class="option">
       -f
      </code>
     </p>
     <div class="informaltable">
      <table frame="box" rules="all" summary="Properties for force">
       <colgroup>
        <col style="width: 30%"/>
        <col style="width: 70%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Command-Line Format
         </th>
         <td>
          <code class="literal">
           --force
          </code>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <a class="indexterm" name="idm46045307174736">
     </a>
     <a class="indexterm" name="idm46045307173248">
     </a>
     <p>
      Do a repair operation automatically if
      <a class="link" href="myisamchk.html" title="6.6.4 myisamchk — MyISAM Table-Maintenance Utility">
       <span class="command">
        <strong>
         myisamchk
        </strong>
       </span>
      </a>
      finds any errors in the table.
            The repair type is the same as that specified with the
      <a class="link" href="myisamchk-repair-options.html#option_myisamchk_recover">
       <code class="option">
        --recover
       </code>
      </a>
      or
      <code class="option">
       -r
      </code>
      option.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="option_myisamchk_information">
      </a>
      <a class="link" href="myisamchk-check-options.html#option_myisamchk_information">
       <code class="option">
        --information
       </code>
      </a>
      ,
      <code class="option">
       -i
      </code>
     </p>
     <div class="informaltable">
      <table frame="box" rules="all" summary="Properties for information">
       <colgroup>
        <col style="width: 30%"/>
        <col style="width: 70%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Command-Line Format
         </th>
         <td>
          <code class="literal">
           --information
          </code>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <a class="indexterm" name="idm46045307160432">
     </a>
     <a class="indexterm" name="idm46045307158944">
     </a>
     <p>
      Print informational statistics about the table that is
            checked.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="option_myisamchk_medium-check">
      </a>
      <a class="link" href="myisamchk-check-options.html#option_myisamchk_medium-check">
       <code class="option">
        --medium-check
       </code>
      </a>
      ,
      <code class="option">
       -m
      </code>
     </p>
     <div class="informaltable">
      <table frame="box" rules="all" summary="Properties for medium-check">
       <colgroup>
        <col style="width: 30%"/>
        <col style="width: 70%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Command-Line Format
         </th>
         <td>
          <code class="literal">
           --medium-check
          </code>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <a class="indexterm" name="idm46045307148896">
     </a>
     <a class="indexterm" name="idm46045307147408">
     </a>
     <p>
      Do a check that is faster than an
      <a class="link" href="myisamchk-check-options.html#option_myisamchk_extend-check">
       <code class="option">
        --extend-check
       </code>
      </a>
      operation.
            This finds only 99.99% of all errors, which should be good
            enough in most cases.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="option_myisamchk_read-only">
      </a>
      <a class="link" href="myisamchk-check-options.html#option_myisamchk_read-only">
       <code class="option">
        --read-only
       </code>
      </a>
      ,
      <code class="option">
       -T
      </code>
     </p>
     <div class="informaltable">
      <table frame="box" rules="all" summary="Properties for read-only">
       <colgroup>
        <col style="width: 30%"/>
        <col style="width: 70%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Command-Line Format
         </th>
         <td>
          <code class="literal">
           --read-only
          </code>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <a class="indexterm" name="idm46045307136288">
     </a>
     <a class="indexterm" name="idm46045307134800">
     </a>
     <p>
      Do not mark the table as checked. This is useful if you use
      <a class="link" href="myisamchk.html" title="6.6.4 myisamchk — MyISAM Table-Maintenance Utility">
       <span class="command">
        <strong>
         myisamchk
        </strong>
       </span>
      </a>
      to check a table that is in use
            by some other application that does not use locking, such as
      <a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
       <span class="command">
        <strong>
         mysqld
        </strong>
       </span>
      </a>
      when run with external locking
            disabled.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="option_myisamchk_update-state">
      </a>
      <a class="link" href="myisamchk-check-options.html#option_myisamchk_update-state">
       <code class="option">
        --update-state
       </code>
      </a>
      ,
      <code class="option">
       -U
      </code>
     </p>
     <div class="informaltable">
      <table frame="box" rules="all" summary="Properties for update-state">
       <colgroup>
        <col style="width: 30%"/>
        <col style="width: 70%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Command-Line Format
         </th>
         <td>
          <code class="literal">
           --update-state
          </code>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <a class="indexterm" name="idm46045307122096">
     </a>
     <a class="indexterm" name="idm46045307120608">
     </a>
     <p>
      Store information in the
      <code class="filename">
       .MYI
      </code>
      file to
            indicate when the table was checked and whether the table
            crashed. This should be used to get full benefit of the
      <a class="link" href="myisamchk-check-options.html#option_myisamchk_check-only-changed">
       <code class="option">
        --check-only-changed
       </code>
      </a>
      option, but you shouldn't use this option if the
      <a class="link" href="mysqld.html" title="6.3.1 mysqld — The MySQL Server">
       <span class="command">
        <strong>
         mysqld
        </strong>
       </span>
      </a>
      server is using the table and you
            are running it with external locking disabled.
     </p>
    </li>
   </ul>
  </div>
 </div>
 <br/>
</div>
