title: Why Planing time and Execution time are so different Postgres?
body: <p>I make such a query</p>
  
  <pre><code>EXPLAIN (ANALYZE ,BUFFERS )
          SELECT COUNT(id) q, day
          FROM my_table
          WHERE role_id &amp;&amp; ARRAY[15, 17]
          GROUP BY "day"
          ORDER BY "day" DESC;
  </code></pre>
  
  <p>And Postgres responds me with this:</p>
  
  <blockquote>
    <p>Planning time: 0.286 ms<br>
    Execution time: 127.233 ms</p>
  </blockquote>
  
  <p>Why is this ? The difference is too big I think</p>