How to explode columns?
<p>After:</p>

<pre><code>val df = Seq((1, Vector(2, 3, 4)), (1, Vector(2, 3, 4))).toDF("Col1", "Col2")
</code></pre>

<p>I have this DataFrame in Apache Spark: </p>

<pre><code>+------+---------+
| Col1 | Col2    |
+------+---------+
|  1   |[2, 3, 4]|
|  1   |[2, 3, 4]|
+------+---------+
</code></pre>

<p>How do I convert this into:</p>

<pre><code>+------+------+------+------+
| Col1 | Col2 | Col3 | Col4 |
+------+------+------+------+
|  1   |  2   |  3   |  4   |
|  1   |  2   |  3   |  4   |
+------+------+------+------+
</code></pre>