title: Postgres select query
body: <p>I have this question :</p>
  
  <blockquote>
    <p>Find the PCs' markers with at least 3 differents speed</p>
  </blockquote>
  
  <p>using this query:</p>
  
  <pre><code>select p.marker,p.type,speed
      from product as p
      join pc  as pc on(p.model = pc.model)
      order by marker,speed
  </code></pre>
  
  <p>I can see the table with all markers, models and their specific speed. But how can I show only the markers with more than 3 speeds? Using this query I can identify which marker has more than 3, but I want the query precisely in the answer.So It'll return just the markers I want</p>