diff --git a/core/src/main/scala/org/apache/spark/sql/execution/CoprocessorRDD.scala b/core/src/main/scala/org/apache/spark/sql/execution/CoprocessorRDD.scala
index aa5c35f3f7..8f0f390c6b 100644
--- a/core/src/main/scala/org/apache/spark/sql/execution/CoprocessorRDD.scala
+++ b/core/src/main/scala/org/apache/spark/sql/execution/CoprocessorRDD.scala
@@ -261,7 +261,7 @@ case class RegionTaskExec(child: SparkPlan,
         taskCount += 1
         val task = new Callable[util.Iterator[TiRow]] {
           override def call(): util.Iterator[TiRow] =
-            CoprocessIterator.getRowIterator(dagRequest.copy(), tasks, session)
+            CoprocessIterator.getRowIterator(dagRequest, tasks, session)
         }
         completionService.submit(task)
       }
diff --git a/core/src/test/scala/org/apache/spark/sql/test/SharedSQLContext.scala b/core/src/test/scala/org/apache/spark/sql/test/SharedSQLContext.scala
index 63093b1c23..61c8b8201b 100644
--- a/core/src/test/scala/org/apache/spark/sql/test/SharedSQLContext.scala
+++ b/core/src/test/scala/org/apache/spark/sql/test/SharedSQLContext.scala
@@ -19,11 +19,9 @@ package org.apache.spark.sql.test
 
 import java.io.File
 import java.sql.{Connection, DriverManager, Statement}
-import java.util
 import java.util.{Locale, Properties, TimeZone}
 
 import com.pingcap.tispark.TiConfigConst.PD_ADDRESSES
-import com.pingcap.tispark.TiDBOptions
 import com.pingcap.tispark.statistics.StatisticsManager
 import org.apache.spark.internal.Logging
 import org.apache.spark.sql._
diff --git a/tikv-client/src/main/java/com/pingcap/tikv/operation/SchemaInfer.java b/tikv-client/src/main/java/com/pingcap/tikv/operation/SchemaInfer.java
index deaccb5996..c40f7f614a 100644
--- a/tikv-client/src/main/java/com/pingcap/tikv/operation/SchemaInfer.java
+++ b/tikv-client/src/main/java/com/pingcap/tikv/operation/SchemaInfer.java
@@ -43,7 +43,7 @@ public static SchemaInfer create(TiDAGRequest dagRequest) {
   }
 
   public static SchemaInfer create(TiDAGRequest dagRequest, boolean readHandle) {
-    return new SchemaInfer(dagRequest, readHandle);
+    return new SchemaInfer(dagRequest.copy(), readHandle);
   }
 
   private SchemaInfer(TiDAGRequest dagRequest, boolean readHandle) {
diff --git a/tikv-client/src/main/java/com/pingcap/tikv/operation/iterator/CoprocessIterator.java b/tikv-client/src/main/java/com/pingcap/tikv/operation/iterator/CoprocessIterator.java
index 77d921535f..a35922a7ea 100644
--- a/tikv-client/src/main/java/com/pingcap/tikv/operation/iterator/CoprocessIterator.java
+++ b/tikv-client/src/main/java/com/pingcap/tikv/operation/iterator/CoprocessIterator.java
@@ -71,12 +71,13 @@ public abstract class CoprocessIterator<T> implements Iterator<T> {
    */
   public static CoprocessIterator<Row> getRowIterator(
       TiDAGRequest req, List<RegionTask> regionTasks, TiSession session) {
+    TiDAGRequest dagRequest = req.copy();
     return new DAGIterator<Row>(
-        req.buildTableScan(),
+        dagRequest.buildTableScan(),
         regionTasks,
         session,
-        SchemaInfer.create(req),
-        req.getPushDownType()) {
+        SchemaInfer.create(dagRequest),
+        dagRequest.getPushDownType()) {
       @Override
       public Row next() {
         if (hasNext()) {