From b508d4ae5546839f6f45c1a7f2fa5fd50bf64d33 Mon Sep 17 00:00:00 2001
From: qiaojialin <646274302@qq.com>
Date: Wed, 4 Mar 2020 16:45:43 +0800
Subject: [PATCH] change default fill function to previous

---
 .../2-DML (Data Manipulation Language).md        |  8 ++++----
 .../db/query/executor/FillQueryExecutor.java     | 16 ++--------------
 .../db/integration/IoTDBAlignByDeviceIT.java     |  2 +-
 3 files changed, 7 insertions(+), 19 deletions(-)

diff --git a/docs/Documentation/UserGuide/5-Operation Manual/2-DML (Data Manipulation Language).md b/docs/Documentation/UserGuide/5-Operation Manual/2-DML (Data Manipulation Language).md
index 18d788feba27..695d955f40d5 100644
--- a/docs/Documentation/UserGuide/5-Operation Manual/2-DML (Data Manipulation Language).md	
+++ b/docs/Documentation/UserGuide/5-Operation Manual/2-DML (Data Manipulation Language).md	
@@ -408,10 +408,10 @@ When the fill method is not specified, each data type bears its own default fill
 |Data Type|Default Fill Methods and Parameters|
 |:---|:---|
 |boolean|previous, 600000|
-|int32|linear, 600000, 600000|
-|int64|linear, 600000, 600000|
-|float|linear, 600000, 600000|
-|double|linear, 600000, 600000|
+|int32|previous, 600000|
+|int64|previous, 600000|
+|float|previous, 600000|
+|double|previous, 600000|
 |text|previous, 600000|
 </center>
 
diff --git a/server/src/main/java/org/apache/iotdb/db/query/executor/FillQueryExecutor.java b/server/src/main/java/org/apache/iotdb/db/query/executor/FillQueryExecutor.java
index d17f7b8ab126..4ddabad67447 100644
--- a/server/src/main/java/org/apache/iotdb/db/query/executor/FillQueryExecutor.java
+++ b/server/src/main/java/org/apache/iotdb/db/query/executor/FillQueryExecutor.java
@@ -71,20 +71,8 @@ public QueryDataSet execute(QueryContext context)
       IFill fill;
       long defaultFillInterval = IoTDBDescriptor.getInstance().getConfig().getDefaultFillInterval();
       if (!typeIFillMap.containsKey(dataType)) {
-        switch (dataType) {
-          case INT32:
-          case INT64:
-          case FLOAT:
-          case DOUBLE:
-            fill = new LinearFill(dataType, queryTime, defaultFillInterval, defaultFillInterval);
-            break;
-          case BOOLEAN:
-          case TEXT:
-            fill = new PreviousFill(dataType, queryTime, defaultFillInterval);
-            break;
-          default:
-            throw new UnsupportedDataTypeException("do not support datatype " + dataType);
-        }
+        // the default fill function is PreviousFill for all data type
+        fill = new PreviousFill(dataType, queryTime, defaultFillInterval);
       } else {
         fill = typeIFillMap.get(dataType).copy();
       }
diff --git a/server/src/test/java/org/apache/iotdb/db/integration/IoTDBAlignByDeviceIT.java b/server/src/test/java/org/apache/iotdb/db/integration/IoTDBAlignByDeviceIT.java
index 86aadafe5a35..f6b1e37188d3 100644
--- a/server/src/test/java/org/apache/iotdb/db/integration/IoTDBAlignByDeviceIT.java
+++ b/server/src/test/java/org/apache/iotdb/db/integration/IoTDBAlignByDeviceIT.java
@@ -513,7 +513,7 @@ public void groupByTimeTest() throws ClassNotFoundException {
   @Test
   public void fillTest() throws ClassNotFoundException {
     String[] retArray = new String[]{
-        "3,root.vehicle.d0,10000,40208,3.33,null,null,",
+        "3,root.vehicle.d0,10000,40000,3.33,null,null,",
         "3,root.vehicle.d1,999,null,null,null,null,",
     };