title: Error during execution of Postgresql query on Cube data type column
body: <p>I am new to Postgesql. I have created a table with fields <code>(Id integer, name text, url text, vector cube)</code> named <code>images</code>.</p>
  
  <p>Now I want to search K nearest values to a new cube variable using <code>&lt;-&gt;</code> (euclidean distance ) operator. My query is as follows(I have assumed that data column is 3D):</p>
  
  <pre><code>Select * 
  from images 
  order by vector &lt;-&gt; cube(array[0.5, 0.3, 0.2]) 
  limit 5
  </code></pre>
  
  <p>But following error occurs:</p>
  
  <pre class="lang-none prettyprint-override"><code>ERROR:  operator does not exist: cube &lt;-&gt; cube
  LINE 1: Select * from test order by data &lt;-&gt; cube(array[0.5, 0.3, 0.2...
  HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
  SQL state: 42883
  Character: 38
  </code></pre>
  
  <p>Kindly do help me. Thanks. I am using Ubuntu 16.04.6 LTS and Postgresql version 9.5.19. </p>
  
  <p>Screen shots of my table and error are attached below:</p>
  
  <p><a href="https://i.stack.imgur.com/Q2vm6.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Q2vm6.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/V7wRP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/V7wRP.png" alt="enter image description here"></a></p>