modify data manipulation doc (#1678)

docs/SystemDesign/StorageEngine/DataManipulation.md

@@ -35,7 +35,7 @@ The following describes four common data manipulation operations, which are inse
   * Find the corresponding TsFileProcessor according to the time of writing the data and the last time stamp of the current device order
   * Write to the corresponding memtable of TsFileProcessor
       * If the file is out of order, update the endTimeMap in tsfileResource
-      * If there is no information about the device in tsfile, then update the startTimeMap in tsfileResource
+      * If there is no information about the device in tsfile, or the time of inserted data newly is less than startTime stored, then update the startTimeMap in tsfileResource
   * Pre-write log
   * Determine whether to trigger asynchronous persistent memtable operation based on memtable size
       * If it is a sequential file and the flashing action is performed, the endTimeMap in tsfileResource is updated
@@ -51,7 +51,7 @@ The following describes four common data manipulation operations, which are inse
 	* According to the time of this batch of data and the last timestamp of the current device order, this batch of data is divided into small batches, which correspond to a TsFileProcessor
 	* Write each small batch to the corresponding memtable of TsFileProcessor
 	    * If the file is out of order, update the endTimeMap in tsfileResource
-	    * If there is no information about the device in tsfile, then update the startTimeMap in tsfileResource
+	    * If there is no information about the device in tsfile, or the time of inserted data newly is less than startTime stored, then update the startTimeMap in tsfileResource
 	* Pre-write log
 	* Determine whether to trigger asynchronous persistent memtable operation based on memtable size
 	    * If it is a sequential file and the flashing action is performed, the endTimeMap in tsfileResource is updated

docs/zh/SystemDesign/StorageEngine/DataManipulation.md

@@ -36,7 +36,7 @@
 	* 根据写入数据的时间以及当前设备落盘的最后时间戳，找到对应的 TsFileProcessor
 	* 写入 TsFileProcessor 对应的 memtable 中
 	    * 如果是乱序文件，则更新tsfileResource中的endTimeMap
-	    * 如果tsfile中没有该设备的信息，则更新tsfileResource中的startTimeMap
+	    * 如果tsfile中没有该设备的信息，或新插入数据的时间小于已存startTime，则更新tsfileResource中的startTimeMap
 	* 记录写前日志
 	* 根据 memtable 大小，来判断是否触发异步持久化 memtable 操作
 	    * 如果是顺序文件且执行了刷盘动作，则更新tsfileResource中的endTimeMap
@@ -52,7 +52,7 @@
 	* 根据这批数据的时间以及当前设备落盘的最后时间戳，将这批数据分成小批，分别对应到一个 TsFileProcessor 中
 	* 分别将每小批写入 TsFileProcessor 对应的 memtable 中
 	    * 如果是乱序文件，则更新tsfileResource中的endTimeMap
-	    * 如果tsfile中没有该设备的信息，则更新tsfileResource中的startTimeMap
+	    * 如果tsfile中没有该设备的信息，或新插入数据的时间小于已存startTime，则更新tsfileResource中的startTimeMap
 	* 记录写前日志
 	* 根据 memtable 大小，来判断是否触发异步持久化 memtable 操作
 	    * 如果是顺序文件且执行了刷盘动作，则更新tsfileResource中的endTimeMap
@@ -102,4 +102,4 @@ Mods文件用来存储所有的删除记录。下图的mods文件中，d1.s1落
 
 同时，我们在 StorageEngine 中启动了一个定时检查文件TTL的线程，详见
 
-* src/main/java/org/apache/iotdb/db/engine/StorageEngine.java 中的 start 方法
\ No newline at end of file
+* src/main/java/org/apache/iotdb/db/engine/StorageEngine.java 中的 start 方法