title: How Atomic are Mysql Transactions given multiple connections?
body: <p>I checked related questions, the answer is <em>kinda</em> "yes, very atomic".</p>
  
  <p>But Im going more specific, because those questions were not that specific and so the answers:</p>
  
  <ol>
  <li>MySQL/INNODB</li>
  <li>Several connections at the "same" time</li>
  <li>A transaction probably WRITING the same tables (even more, the same
      queries).</li>
  <li>Only one database</li>
  <li>No lock table will be done at all</li>
  <li>. No nested transactions</li>
  <li>No memcache or any othe similar system, everything as simple as
  possible.</li>
  <li>I <em>believe</em> we are using "serializable isoloation, not low level"</li>
  </ol>
  
  <p>In this scenario, are we garanteed by Mysql engine that data integrity will be mantained, or going to specific cases:</p>
  
  <ul>
  <li><p>Those "at the same time " writings will be queued?</p></li>
  <li><p>Rollback in fact will work as spected.</p></li>
  <li><p>readings at "the same time" will find a consistency int the state for
  those writings?</p></li>
  </ul>
  
  <p>My simple concerns is that if "commits" and "rollbacks" inside transcations of different connections are atomic or they just make a mess :-)</p>
  
  <p>Thanks.</p>