Github user ppadma commented on a diff in the pull request:
https://github.com/apache/drill/pull/1091#discussion_r164233329
--- Diff:
exec/java-exec/src/test/java/org/apache/drill/exec/physical/unit/TestOutputBatchSize.java
---
@@ -0,0 +1,498 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ * <p/>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p/>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.drill.exec.physical.unit;
+
+import com.google.common.collect.Lists;
+import org.apache.drill.common.expression.SchemaPath;
+
+import org.apache.drill.exec.physical.base.AbstractBase;
+import org.apache.drill.exec.physical.base.PhysicalOperator;
+import org.apache.drill.exec.physical.config.FlattenPOP;
+import org.apache.drill.exec.physical.impl.ScanBatch;
+import org.apache.drill.exec.physical.impl.spill.RecordBatchSizer;
+import org.apache.drill.exec.record.RecordBatch;
+import org.apache.drill.exec.record.VectorAccessible;
+import org.apache.drill.exec.util.JsonStringArrayList;
+import org.apache.drill.exec.util.JsonStringHashMap;
+import org.apache.drill.exec.util.Text;
+import org.junit.Ignore;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class TestOutputBatchSize extends PhysicalOpUnitTestBase {
--- End diff --
I added a test case like this, testFlattenLargeRecords and there are bunch
of other test cases as well.
All the tests are verifying the batch sizes and number of batches.
---
