Server-side warning: Aggregation query used without partition key : <p>While using the C/C++ driver of Cassandra, I at times see these kind of messages popping up in my console:</p>

<pre><code>1460937092.140 [WARN] (src/response.cpp:51:char*
      cass::Response::decode_warnings(char*, size_t)):
      Server-side warning: Aggregation query used without partition key
</code></pre>

<p>Wondering whether someone knows what that means. What should I be looking for in my code that could generate this error, or is it just something on the server side that I have no control over?</p>
