Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/4652#discussion_r143956930
--- Diff: docs/dev/table/sql.md ---
@@ -2020,7 +2020,16 @@ COUNT(*)
<p>Returns the number of input rows.</p>
</td>
</tr>
-
+<tr>
+ <td>
+ {% highlight text %}
+CARDINALITY_COUNT(rsd, value)
--- End diff --
I agree with @jparkie. It must be clear from the name of the function that
it computes an approximated count.---
