[fix](be) Return NaN for avg_weighted when sum of weights is zero

be/src/exprs/aggregate/aggregate_function_avg_weighted.h

@@ -22,6 +22,7 @@
 #include <algorithm>
 #include <boost/iterator/iterator_facade.hpp>
 #include <cmath>
+#include <limits>
 #include <memory>
 #include <type_traits>
 
@@ -76,7 +77,12 @@ struct AggregateFunctionAvgWeightedData {
         weight_sum = 0.0;
     }
 
-    double get() const { return data_sum / weight_sum; }
+    double get() const {
+        if (weight_sum == 0.0) {
+            return std::numeric_limits<double>::quiet_NaN();
+        }
+        return data_sum / weight_sum;
+    }
 
     double data_sum = 0.0;
     double weight_sum = 0.0;

regression-test/data/query_p0/aggregate/support_type/avg_weighted/avg_weighted.out

@@ -2,3 +2,6 @@
 -- !sql_double --
 2.718281828
 
+-- !sql_zero_weight --
+NaN
+

regression-test/suites/query_p0/aggregate/support_type/avg_weighted/avg_weighted.groovy

@@ -43,4 +43,18 @@ suite("avg_weighted") {
     """
 
     qt_sql_double """select avg_weighted(col_double, weight_double) from d_table;"""
+
+    // weight sum is zero, should return NaN instead of +/-Infinity
+    sql """
+        drop table if exists test_avg_weighted_zero;
+    """
+    sql """
+        create table test_avg_weighted_zero (f1 int, f2 int)
+        distributed BY hash(f1) buckets 1
+        properties("replication_num" = "1");
+    """
+    sql """
+        insert into test_avg_weighted_zero values (1, 1), (2, -1);
+    """
+    qt_sql_zero_weight """select avg_weighted(f1, f2) from test_avg_weighted_zero;"""
 }