I think this need precision_threshold offset. In my cluster, there is slow query problem with precision_threshold. With 40000, cardinality agg is too slow. So it will be good for this project.

nignus · nignus · commit 386f79e43972 · 2016-01-25T19:26:13.000+09:00
diff --git a/src/main/java/org/nlpcn/es4sql/query/maker/AggMaker.java b/src/main/java/org/nlpcn/es4sql/query/maker/AggMaker.java
@@ -462,7 +462,8 @@ private AbstractAggregationBuilder makeCountAgg(MethodField field) {
 
 		// Cardinality is approximate DISTINCT.
 		if ("DISTINCT".equals(field.getOption())) {
-			return AggregationBuilders.cardinality(field.getAlias()).precisionThreshold(40000).field(field.getParams().get(0).value.toString());
+            Integer precision_threshold = field.getParams().size()>1 ? (Integer)(field.getParams().get(1).value)  : 40000;
+			return AggregationBuilders.cardinality(field.getAlias()).precisionThreshold(precision_threshold).field(field.getParams().get(0).value.toString());
 		}
 
 		String fieldName = field.getParams().get(0).value.toString();

Original file line number	Diff line number	Diff line change
`@@ -462,7 +462,8 @@ private AbstractAggregationBuilder makeCountAgg(MethodField field) {`
`462`	`462`
`463`	`463`	`// Cardinality is approximate DISTINCT.`
`464`	`464`	`if ("DISTINCT".equals(field.getOption())) {`
`465`		`- return AggregationBuilders.cardinality(field.getAlias()).precisionThreshold(40000).field(field.getParams().get(0).value.toString());`
	`465`	`+ Integer precision_threshold = field.getParams().size()>1 ? (Integer)(field.getParams().get(1).value) : 40000;`
	`466`	`+ return AggregationBuilders.cardinality(field.getAlias()).precisionThreshold(precision_threshold).field(field.getParams().get(0).value.toString());`
`466`	`467`	`}`
`467`	`468`
`468`	`469`	`String fieldName = field.getParams().get(0).value.toString();`