title: Does spark load whole data from cassandra
body: <p>I have following code.</p>
  
  <pre><code>Dataset&lt;Row&gt; kpiDF = spark.read().format("org.apache.spark.sql.cassandra")
  .options(new HashMap&lt;String, String&gt;(){{put("keyspace",keyspace);put("table", table);}})
  .load()
  .filter("kpi='test'")
  </code></pre>
  
  <p>my question is, where this will load all the data from cassandra table and then apply filter or it will only load 'test' kpi data from cassandra? </p>