title: mysqldump test locking tables
body: <p>We have production mysql DB around <code>35G</code> (innoDB) and we have notice when <code>mysqldump</code> start application get unstable. we use following command to run dump</p>
  
  <p><code>mysqldump --password=XXXX --add-drop-table foo | gzip -c &gt; foo.dmp.gz</code></p>
  
  <p>after googling people said <code>mysqldump</code> lock table before dumping data so people suggested using <code>--single-transaction</code> flag for <code>innoDB</code> </p>
  
  <p>so for experiment i started mysqldump manually and run some query on tables read/write and it allowed me to perform all operation while mysqldump was running so how do i reproduce this behavior that mysqldump really locking my table which causing application accessibility?  </p>
  
  <ul>
  <li>Does mysqldump lock Read Operation or Just Write on table? </li>
  <li>We have few DB using <code>MyISAM</code> in that case what we should do to avoid locks</li>
  </ul>