Spark write parquet not writing any files, only _SUCCESS
<p>The application includes</p>

<pre><code>val stats = sqlContext.sql("select id, n from myTable")

stats.write.parquet("myTable.parquet")
</code></pre>

<p>This creates dir <code>myTable.parquet</code> with no contents other than an empty <code>_SUCCESS</code> file, even that</p>

<pre><code>stats.show  // illustration only here, original size motivates parquet use

+-----+----+
|  id |  n |
+-----+----+
|   a |  1 |
|   b |  2 |
+-----+----+

stats.printSchema 

root
 |-- id: string (nullable = true)
 |-- n: long (nullable = true)
</code></pre>

<p>How to make <code>write.parquet</code> to write the actual contents of the dataframe ? What is missing ?</p>

<p><strong>Note</strong> This occurs also with <code>saveAsTextFile</code>.</p>