title: Do MySQL Locked Tables affect related Views?
body: <p>So after reading <a href="https://stackoverflow.com/questions/1415602/performance-in-pdo-php-mysql-transaction-versus-direct-execution">Performance in PDO / PHP / MySQL: transaction versus direct execution</a> in regards to performance issues I was thinking about I did some research on locking tables in MySQL. </p>
  
  <p>On <a href="http://dev.mysql.com/doc/refman/5.0/en/table-locking.html" rel="nofollow noreferrer">http://dev.mysql.com/doc/refman/5.0/en/table-locking.html</a></p>
  
  <blockquote>
    <p>Table locking enables many sessions to
    read from a table at the same time,
    but if a session wants to write to a
    table, it must first get exclusive
    access. During the update, all other
    sessions that want to access this
    particular table must wait until the
    update is done.</p>
  </blockquote>
  
  <p>This part struck me particularly because most of our queries will be updates rather than inserts. I was wondering if one created a table called foo on which all updates/inserts were carried out and then a view called foo_view (A copy of foo, or perhaps foo and a linkage of several other tables plus foo) on which all selects occurred, would this locking issue still occur?</p>
  
  <p>That is, would SELECT queries on foo_view still have to wait for an update to finish on foo?</p>
  
  <p>Another brief question my colleague asked. Does this affect caching? I.e. if the SELECT is cached will it hit the cache and return results, or will it wait for the lock to finish first?</p>