fix a bug in aggregation without filter process (#377)

Author: Beyyes

src/main/java/cn/edu/tsinghua/iotdb/query/engine/OverflowQueryEngine.java

@@ -118,6 +118,8 @@ public QueryDataSet aggregate(List<Pair<Path, String>> aggres, List<FilterStruct
             if (aggregateFunction.resultData.timeLength == 0) {
                 aggregateFunction.putDefaultValue();
             }
+            LOGGER.debug(String.format("key %s, data length %s, empty data length %s", EngineUtils.aggregationKey(aggregateFunction, pair.left),
+                    aggregateFunction.resultData.timeLength, aggregateFunction.resultData.emptyTimeLength));
             ansQueryDataSet.mapRet.put(EngineUtils.aggregationKey(aggregateFunction, pair.left), aggregateFunction.resultData);
         }
         // aggregateThreadLocal.set(ansQueryDataSet);

src/main/java/cn/edu/tsinghua/iotdb/query/reader/AggregateRecordReader.java

@@ -231,7 +231,8 @@ private void aggregate(ValueReader valueReader, AggregateFunction func) throws I
                 valueReader.setDecoder(Decoder.getDecoderByType(pageHeader.getData_page_header().getEncoding(), dataType));
                 result = ReaderUtils.readOnePage(dataType, timestamps, valueReader.decoder, page, result,
                         queryTimeFilter, queryValueFilter, insertMemoryData, overflowOperationReaderCopy);
-                func.calculateValueFromDataPage(result);
+                if (result.valueLength > 0)
+                    func.calculateValueFromDataPage(result);
                 result.clearData();
             }
         }

src/test/java/cn/edu/tsinghua/iotdb/service/LargeDataTest.java

@@ -66,9 +66,9 @@ public void setUp() throws Exception {
             pageSizeInByte = tsFileConfig.pageSizeInByte;
             groupSizeInByte = tsFileConfig.groupSizeInByte;
             // new value
-            tsFileConfig.maxNumberOfPointsInPage = 100;
-            tsFileConfig.pageSizeInByte = 1024 * 1024 * 15;
-            tsFileConfig.groupSizeInByte = 1024 * 1024 * 100;
+            tsFileConfig.maxNumberOfPointsInPage = 1000;
+            tsFileConfig.pageSizeInByte = 1024 * 1024 * 150;
+            tsFileConfig.groupSizeInByte = 1024 * 1024 * 1000;
 
             deamon = IoTDB.getInstance();
             deamon.active();
@@ -425,6 +425,24 @@ private void allNullSeriesAggregationTest() throws ClassNotFoundException, SQLEx
             assertEquals(1, cnt);
             statement.close();
 
+            // (3). aggregation test : there is no value in series d1.s0 in the given time range
+            sql = "select max_value(s0),min_value(s0)" +
+                    "from root.vehicle.d0 where time > 13601 and time < 13602";
+            statement = connection.createStatement();
+            hasResultSet = statement.execute(sql);
+            Assert.assertTrue(hasResultSet);
+            resultSet = statement.getResultSet();
+            cnt = 0;
+            while (resultSet.next()) {
+                String ans = resultSet.getString(TIMESTAMP_STR)
+                        + "," + resultSet.getString(max_value(d0s0)) + "," + resultSet.getString(min_value(d0s0));
+                assertEquals("0,null,null", ans);
+                //System.out.println(".." + ans);
+                cnt++;
+            }
+            assertEquals(1, cnt);
+            statement.close();
+
         } catch (Exception e) {
             e.printStackTrace();
             fail(e.getMessage());
@@ -865,7 +883,7 @@ private void insertSQL() throws ClassNotFoundException, SQLException {
                 statement.execute(sql);
             }
 
-            statement.execute("flush");
+            // statement.execute("flush");
 
             // insert large amount of data time range : 13700 ~ 24000
             for (int time = 13700; time < 24000; time++) {