title: What would be the minimal keys of this relation?
body: <p>R(ABCDE)</p>
  
  <p>List of FDs</p>
  
  <p><code>AB</code>→<code>C</code>,
  <code>BC</code>→<code>D</code>,
  <code>CD</code>→<code>E</code>,
  <code>DE</code>→<code>A</code></p>
  
  <p>Now, we would find the minimal keys:</p>
  
  <p>Since, we don’t see <code>B</code> on the left hand side, we will start with <code>B</code>.</p>
  
  <p>Now, </p>
  
  <h2>{B}+</h2>
  
  <p>B</p>
  
  <p>Nothing comes. So, we will have to add another attribute with B. </p>
  
  <p>Let’s start with A.</p>
  
  <h2><code>{AB}+</code></h2>
  
  <p><code>AB</code>
  <code>=&gt; ABC [AB -&gt; C]</code>
  <code>=&gt; ABCD [BC -&gt; D]</code>
  <code>=&gt; ABCDE [CD -&gt; E]</code>. So, AB is a minimal key.</p>
  
  <h2><code>{BC}+</code></h2>
  
  <p><code>BC</code>
  <code>=&gt; BCD [BC -&gt; D]</code>
  <code>=&gt; BCDE [CD -&gt; E]</code>
  <code>=&gt; ABCDE [DE -&gt; A]</code>. So, BC is a minimal key.</p>
  
  <h2>{BD}+</h2>
  
  <p><code>BD</code>    Nothing is possible further. So, BD is not a minimal key.</p>
  
  <h2>{BE}+</h2>
  
  <p><code>BE</code>        Nothing is possible further. So, BE is not a minimal key.</p>
  
  <p>Now, I have the follwing questions:</p>
  
  <ol>
  <li>Does this relation have more minimal keys?</li>
  <li>What are they? Are they BDE, BDA? Why?</li>
  </ol>