diff --git a/src/sql/engine/connect_by/ob_nl_cnnt_by_with_index_op.cpp b/src/sql/engine/connect_by/ob_nl_cnnt_by_with_index_op.cpp
index 5834871bf5..437fcfd983 100644
--- a/src/sql/engine/connect_by/ob_nl_cnnt_by_with_index_op.cpp
+++ b/src/sql/engine/connect_by/ob_nl_cnnt_by_with_index_op.cpp
@@ -31,7 +31,6 @@ ObNLConnectByWithIndexOp::ObNLConnectByWithIndexOp(ObExecContext& exec_ctx, cons
       is_match_(false),
       is_cycle_(false),
       is_inited_(false),
-      open_right_child_(false),
       need_return_(false)
 {
   state_operation_func_[CNTB_STATE_JOIN_END] = &ObNLConnectByWithIndexOp::join_end_operate;
@@ -89,7 +88,6 @@ void ObNLConnectByWithIndexOp::reset()
   root_row_ = NULL;
   cur_output_row_ = NULL;
   is_inited_ = false;
-  open_right_child_ = false;
   sys_connect_by_path_id_ = INT64_MAX;
   need_return_ = false;
 }
@@ -99,8 +97,6 @@ int ObNLConnectByWithIndexOp::inner_open()
   int ret = OB_SUCCESS;
   if (OB_FAIL(ObOperator::inner_open())) {
     LOG_WARN("failed to open in base class", K(ret));
-  } else if (OB_FAIL(left_->open())) {
-    LOG_WARN("failed to open left child", K(ret));
   } else if (OB_FAIL(init())) {
     LOG_WARN("fail to init Connect by Ctx", K(ret));
   } else if (MY_SPEC.left_prior_exprs_.count() != MY_SPEC.right_prior_exprs_.count()) {
@@ -118,22 +114,11 @@ int ObNLConnectByWithIndexOp::inner_open()
   return ret;
 }
 
-int ObNLConnectByWithIndexOp::open_right_child()
-{
-  int ret = OB_SUCCESS;
-  if (!right_->is_opened() && OB_FAIL(right_->open())) {
-    LOG_WARN("failed to open right child", K(ret));
-  }
-  return ret;
-}
-
 int ObNLConnectByWithIndexOp::rescan()
 {
   int ret = OB_SUCCESS;
   reset();
-  if (OB_FAIL(open_right_child())) {
-    LOG_WARN("failed to open right child", K(ret));
-  } else if (OB_FAIL(ObOperator::rescan())) {
+  if (OB_FAIL(ObOperator::rescan())) {
     LOG_WARN("failed to rescan", K(ret));
   }
   return ret;
@@ -143,15 +128,6 @@ int ObNLConnectByWithIndexOp::inner_close()
 {
   int ret = OB_SUCCESS;
   reset();
-  int left_ret = OB_SUCCESS;
-  int right_ret = OB_SUCCESS;
-  if (OB_SUCCESS != (left_ret = left_->close())) {
-    LOG_WARN("Close child operator failed", K(left_ret), "op_type", ob_phy_operator_type_str(get_spec().type_));
-  }
-  if (OB_SUCCESS != (right_ret = right_->close())) {
-    LOG_WARN("Close child operator failed", K(right_ret), "op_type", ob_phy_operator_type_str(get_spec().type_));
-  }
-  ret = (OB_SUCCESS == left_ret) ? right_ret : left_ret;
   return ret;
 }
 
@@ -291,11 +267,6 @@ int ObNLConnectByWithIndexOp::prepare_rescan_params()
       LOG_WARN("fail to set dynamic param", K(ret));
     }
   }
-  if (OB_SUCC(ret)) {
-    if (OB_FAIL(open_right_child())) {
-      LOG_WARN("failed to open right child", K(ret));
-    }
-  }
   return ret;
 }
 
diff --git a/src/sql/engine/connect_by/ob_nl_cnnt_by_with_index_op.h b/src/sql/engine/connect_by/ob_nl_cnnt_by_with_index_op.h
index 9d46b20417..8fa63a2923 100644
--- a/src/sql/engine/connect_by/ob_nl_cnnt_by_with_index_op.h
+++ b/src/sql/engine/connect_by/ob_nl_cnnt_by_with_index_op.h
@@ -44,7 +44,7 @@ public:
 
   virtual OperatorOpenOrder get_operator_open_order() const override final
   {
-    return OPEN_SELF_ONLY;
+    return OPEN_SELF_FIRST;
   }
 
   int prepare_rescan_params();
@@ -97,7 +97,6 @@ private:
   int add_pseudo_column(ObExpr* pseudo_expr, ObConnectByPseudoColumn column_type);
 
   int init();
-  int open_right_child();
 
 public:
   ObConnectByOpBFSPump connect_by_pump_;
@@ -115,7 +114,6 @@ private:
   bool is_match_;  // whether there is a child, for calc connect_by_isleaf
   bool is_cycle_;  // whether part of a cycle, for calc connect_by_iscycle
   bool is_inited_;
-  bool open_right_child_;
   bool need_return_;
 };
 
diff --git a/src/sql/engine/join/ob_basic_nested_loop_join.cpp b/src/sql/engine/join/ob_basic_nested_loop_join.cpp
index b115713e50..411575b7e9 100644
--- a/src/sql/engine/join/ob_basic_nested_loop_join.cpp
+++ b/src/sql/engine/join/ob_basic_nested_loop_join.cpp
@@ -90,13 +90,6 @@ int ObBasicNestedLoopJoin::prepare_rescan_params(ObBasicNestedLoopJoinCtx& join_
     }
   }
 
-  // try to open the right child
-  if (OB_SUCC(ret)) {
-    if (OB_FAIL(open_right_child(join_ctx))) {
-      LOG_WARN("failed to open right child", K(ret));
-    }
-  }
-
   return ret;
 }
 
@@ -123,99 +116,26 @@ int ObBasicNestedLoopJoin::get_next_left_row(ObJoinCtx& join_ctx) const
   return OB_SUCCESS != ret ? ret : ObJoin::get_next_left_row(join_ctx);
 }
 
-int ObBasicNestedLoopJoin::open_right_child(ObBasicNestedLoopJoinCtx& join_ctx) const
-{
-  int ret = OB_SUCCESS;
-  ObPhyOperator* child_ptr = nullptr;
-  ObPhyOperatorCtx* child_op_ctx = nullptr;
-  if (join_ctx.open_right_child()) {
-    // do nothing
-  } else if (OB_ISNULL(child_ptr = get_child(SECOND_CHILD))) {
-    ret = OB_ERR_UNEXPECTED;
-    LOG_WARN("fail to get right child", K(ret));
-  } else if (OB_NOT_NULL(
-                 child_op_ctx = GET_PHY_OPERATOR_CTX(ObPhyOperatorCtx, join_ctx.exec_ctx_, child_ptr->get_id()))) {
-    // the drain stage will open this operator, and no record in join_ctx.
-    join_ctx.set_open_right_child();
-  } else if (OB_FAIL(open_child(join_ctx.exec_ctx_, SECOND_CHILD))) {
-    LOG_WARN("fail to open right child", K(ret));
-    join_ctx.set_open_right_child();
-  } else {
-    join_ctx.set_open_right_child();
-  }
-  return ret;
-}
-
-int ObBasicNestedLoopJoin::open_left_child(ObExecContext& ctx) const
-{
-  int ret = OB_SUCCESS;
-  if (OB_FAIL(open_child(ctx, FIRST_CHILD))) {
-    LOG_WARN("fail to open left child", K(ret));
-  }
-  return ret;
-}
-
-int ObBasicNestedLoopJoin::inner_open(ObExecContext& ctx) const
+int ObBasicNestedLoopJoin::inner_open(ObExecContext &ctx) const
 {
   int ret = OB_SUCCESS;
   if (OB_FAIL(ObJoin::inner_open(ctx))) {
     LOG_WARN("failed to inner open join", K(ret));
-  } else if (OB_FAIL(open_left_child(ctx))) {
-    LOG_WARN("failed to open left child", K(ret));
   }
   return ret;
 }
 
 int ObBasicNestedLoopJoin::inner_close(ObExecContext& ctx) const
 {
+  UNUSED(ctx);
   int ret = OB_SUCCESS;
-  int child_ret = OB_SUCCESS;
-  // first call close of all children
-  ObPhyOperator* child_ptr = NULL;
-  for (int32_t i = 0; i < get_child_num(); ++i) {
-    if (OB_ISNULL(child_ptr = get_child(i))) {
-      ret = OB_NOT_INIT;
-      LOG_WARN("failed to get child",
-          K(i),
-          K(child_ptr),
-          K(get_child_num()),
-          K(ret),
-          "op_type",
-          ob_phy_operator_type_str(get_type()));
-    } else {
-      int tmp_ret = child_ptr->close(ctx);
-      if (OB_SUCCESS != tmp_ret) {
-        child_ret = tmp_ret;
-        LOG_WARN("Close child operator failed", K(child_ret), "op_type", ob_phy_operator_type_str(get_type()));
-      }
-    }
-  }
-
-  // no matter what, must call operatoris close function, then close this operator
-  ObPhyOperatorCtx* op_ctx = NULL;
-  if (OB_ISNULL(op_ctx = GET_PHY_OPERATOR_CTX(ObPhyOperatorCtx, ctx, get_id()))) {
-    LOG_DEBUG("get_phy_operator_ctx failed", K(ret), K_(id), "op_type", ob_phy_operator_type_str(get_type()));
-  } else {
-    // op_ctx->op_monitor_info_.set_value(CLOSE_TIME, common::ObTimeUtility::current_time());
-  }
-
-  if (OB_SUCC(ret)) {
-    // Can only preserve one error code
-    ret = child_ret;
-  }
   return ret;
 }
 
 int ObBasicNestedLoopJoin::rescan(ObExecContext& ctx) const
 {
   int ret = OB_SUCCESS;
-  ObBasicNestedLoopJoinCtx* join_ctx = NULL;
-  if (OB_ISNULL(join_ctx = GET_PHY_OPERATOR_CTX(ObBasicNestedLoopJoinCtx, ctx, get_id()))) {
-    ret = OB_ERR_UNEXPECTED;
-    LOG_WARN("failed to get join ctx", K(ret));
-  } else if (OB_FAIL(open_right_child(*join_ctx))) {
-    LOG_WARN("failed to open right child", K(ret));
-  } else if (OB_FAIL(ObJoin::rescan(ctx))) {
+  if (OB_FAIL(ObJoin::rescan(ctx))) {
     LOG_WARN("failed to call parent rescan", K(ret));
   } else {
   }
diff --git a/src/sql/engine/join/ob_basic_nested_loop_join.h b/src/sql/engine/join/ob_basic_nested_loop_join.h
index e947f0b703..c0a99d8ce3 100644
--- a/src/sql/engine/join/ob_basic_nested_loop_join.h
+++ b/src/sql/engine/join/ob_basic_nested_loop_join.h
@@ -29,7 +29,7 @@ protected:
     friend class ObBasicNestedLoopJoin;
 
   public:
-    ObBasicNestedLoopJoinCtx(ObExecContext& ctx) : ObJoinCtx(ctx), open_right_child_(false)
+    ObBasicNestedLoopJoinCtx(ObExecContext &ctx) : ObJoinCtx(ctx)
     {}
     virtual ~ObBasicNestedLoopJoinCtx()
     {}
@@ -38,18 +38,9 @@ protected:
     {
       ObJoinCtx::destroy();
     }
-    bool open_right_child()
-    {
-      return open_right_child_;
-    }
-    void set_open_right_child()
-    {
-      open_right_child_ = true;
-    }
 
   protected:
     common::ObExprCtx expr_ctx_;
-    bool open_right_child_;
   };
   struct RescanParam {
     OB_UNIS_VERSION_V(1);
@@ -104,15 +95,11 @@ protected:
   virtual OperatorOpenOrder get_operator_open_order(ObExecContext& ctx) const override
   {
     UNUSED(ctx);
-    return OPEN_SELF_ONLY;
+    return OPEN_SELF_FIRST;
   }
-  virtual int inner_open(ObExecContext& ctx) const override;
-  virtual int inner_close(ObExecContext& exec_ctx) const override;
-  virtual int rescan(ObExecContext& exec_ctx) const override;
-  // open left child
-  int open_left_child(ObExecContext& ctx) const;
-  // open right child
-  int open_right_child(ObBasicNestedLoopJoinCtx& join_ctx) const;
+  virtual int inner_open(ObExecContext &ctx) const override;
+  virtual int inner_close(ObExecContext &exec_ctx) const override;
+  virtual int rescan(ObExecContext &exec_ctx) const override;
 
 protected:
   common::ObFixedArray<RescanParam, common::ObIAllocator> rescan_params_;  // @todo a better name
diff --git a/src/sql/engine/join/ob_basic_nested_loop_join_op.cpp b/src/sql/engine/join/ob_basic_nested_loop_join_op.cpp
index 5fd882377b..4ce47873c0 100644
--- a/src/sql/engine/join/ob_basic_nested_loop_join_op.cpp
+++ b/src/sql/engine/join/ob_basic_nested_loop_join_op.cpp
@@ -22,8 +22,8 @@ namespace sql {
 OB_SERIALIZE_MEMBER(
     (ObBasicNestedLoopJoinSpec, ObJoinSpec), rescan_params_, gi_partition_id_expr_, enable_gi_partition_pruning_);
 
-ObBasicNestedLoopJoinOp::ObBasicNestedLoopJoinOp(ObExecContext& exec_ctx, const ObOpSpec& spec, ObOpInput* input)
-    : ObJoinOp(exec_ctx, spec, input), open_right_child_(false)
+ObBasicNestedLoopJoinOp::ObBasicNestedLoopJoinOp(ObExecContext &exec_ctx, const ObOpSpec &spec, ObOpInput *input)
+    : ObJoinOp(exec_ctx, spec, input)
 {}
 
 int ObBasicNestedLoopJoinOp::inner_open()
@@ -32,53 +32,23 @@ int ObBasicNestedLoopJoinOp::inner_open()
   int64_t left_output_cnt = spec_.get_left()->output_.count();
   if (OB_FAIL(ObJoinOp::inner_open())) {
     LOG_WARN("failed to inner open join", K(ret));
-  } else if (OB_FAIL(left_->open())) {
-    LOG_WARN("failed to open left child", K(ret));
   }
-
   return ret;
 }
 
 int ObBasicNestedLoopJoinOp::rescan()
 {
   int ret = OB_SUCCESS;
-  if (OB_FAIL(open_right_child())) {
-    LOG_WARN("failed to open right child", K(ret));
-  } else if (OB_FAIL(ObJoinOp::rescan())) {
+  if (OB_FAIL(ObJoinOp::rescan())) {
     LOG_WARN("failed to call parent rescan", K(ret));
   }
 
   return ret;
 }
 
-int ObBasicNestedLoopJoinOp::open_right_child()
-{
-  int ret = OB_SUCCESS;
-  if (!right_->is_opened() && OB_FAIL(right_->open())) {
-    LOG_WARN("failed to open right child", K(ret));
-  }
-  return ret;
-}
-
 int ObBasicNestedLoopJoinOp::inner_close()
 {
   int ret = OB_SUCCESS;
-  int left_ret = OB_SUCCESS;
-  int right_ret = OB_SUCCESS;
-  if (OB_ISNULL(left_)) {
-    left_ret = OB_NOT_INIT;
-    LOG_WARN("invalid argument", K(left_), K(ret));
-  } else if (OB_SUCCESS != (left_ret = left_->close())) {
-    LOG_WARN("Close child operator failed", K(left_ret), "op_type", ob_phy_operator_type_str(get_spec().type_));
-  }
-  if (OB_ISNULL(right_)) {
-    right_ret = OB_NOT_INIT;
-    LOG_WARN("invalid argument", K(right_), K(ret));
-  } else if (OB_SUCCESS != (right_ret = right_->close())) {
-    LOG_WARN("Close child operator failed", K(right_ret), "op_type", ob_phy_operator_type_str(get_spec().type_));
-  }
-  ret = (OB_SUCCESS == left_ret) ? right_ret : left_ret;
-
   return ret;
 }
 
@@ -103,6 +73,7 @@ int ObBasicNestedLoopJoinOp::get_next_left_row()
 int ObBasicNestedLoopJoinOp::prepare_rescan_params(bool is_group)
 {
   int ret = OB_SUCCESS;
+  UNUSED(is_group);
   int64_t param_cnt = get_spec().rescan_params_.count();
   for (int64_t i = 0; OB_SUCC(ret) && i < param_cnt; ++i) {
     const ObDynamicParamSetter& rescan_param = get_spec().rescan_params_.at(i);
@@ -121,12 +92,6 @@ int ObBasicNestedLoopJoinOp::prepare_rescan_params(bool is_group)
     }
   }
 
-  if (OB_SUCC(ret) && !is_group) {
-    if (OB_FAIL(open_right_child())) {
-      LOG_WARN("failed to open right child", K(ret));
-    }
-  }
-
   return ret;
 }
 
diff --git a/src/sql/engine/join/ob_basic_nested_loop_join_op.h b/src/sql/engine/join/ob_basic_nested_loop_join_op.h
index 8ae9780387..b3732866d8 100644
--- a/src/sql/engine/join/ob_basic_nested_loop_join_op.h
+++ b/src/sql/engine/join/ob_basic_nested_loop_join_op.h
@@ -53,13 +53,12 @@ public:
   virtual ~ObBasicNestedLoopJoinOp(){};
 
   virtual int inner_open() override;
-  virtual int open_right_child();
   virtual int rescan() override;
   virtual int inner_close() final;
 
   virtual OperatorOpenOrder get_operator_open_order() const override final
   {
-    return OPEN_SELF_ONLY;
+    return OPEN_SELF_FIRST;
   }
 
   int prepare_rescan_params(bool is_group = false);
@@ -78,9 +77,6 @@ public:
   int save_left_row();
   int recover_left_row();
 
-protected:
-  bool open_right_child_;
-
 private:
   DISALLOW_COPY_AND_ASSIGN(ObBasicNestedLoopJoinOp);
 };
diff --git a/src/sql/engine/join/ob_block_based_nested_loop_join.cpp b/src/sql/engine/join/ob_block_based_nested_loop_join.cpp
index b620f2a196..4575038e2c 100644
--- a/src/sql/engine/join/ob_block_based_nested_loop_join.cpp
+++ b/src/sql/engine/join/ob_block_based_nested_loop_join.cpp
@@ -304,13 +304,6 @@ int ObBLKNestedLoopJoin::join_left_func_going(ObBLKNestedLoopJoinCtx& join_ctx,
     }
   }
 
-  // try to open the right child
-  if (OB_SUCC(ret)) {
-    if (OB_FAIL(open_right_child(join_ctx))) {
-      LOG_WARN("failed to open right child", K(ret));
-    }
-  }
-
   if (OB_SUCCESS == ret && JS_JOIN_RIGHT_JOIN == join_ctx.state_) {
     if (OB_FAIL(save_left_row(join_ctx))) {
       LOG_WARN("failed to save left row", K(ret));
diff --git a/src/sql/engine/join/ob_nested_loop_join.cpp b/src/sql/engine/join/ob_nested_loop_join.cpp
index 7f10d86c83..5f9dcf7819 100644
--- a/src/sql/engine/join/ob_nested_loop_join.cpp
+++ b/src/sql/engine/join/ob_nested_loop_join.cpp
@@ -92,9 +92,6 @@ int ObNestedLoopJoin::inner_open(ObExecContext& exec_ctx) const
       ret = OB_ERR_UNEXPECTED;
       LOG_WARN("NULL right table scan", K(ret));
     } else if (FALSE_IT(right_table_scan->set_batch_scan_flag(true))) {
-      // never reach
-    } else if (OB_FAIL(open_right_child(*join_ctx))) {
-      LOG_WARN("failed to open right child", K(ret));
     }
   }
   return ret;
@@ -591,8 +588,6 @@ int ObNestedLoopJoin::bij_fill_left_rows(ObExecContext& exec_ctx) const
   } else if (PHY_TABLE_SCAN != right_op_->get_type()) {
     ret = OB_ERR_UNEXPECTED;
     LOG_ERROR("right op is not TABLE_SCAN type, plan is incorrect", K(ret), K(right_op_->get_type()));
-  } else if (OB_FAIL(open_right_child(*join_ctx))) {
-    LOG_WARN("failed to open right child", K(ret));
   } else {
     ObTableScan* right_table_scan = static_cast<ObTableScan*>(right_op_);
     if (OB_FAIL(right_table_scan->batch_rescan_init(exec_ctx))) {
diff --git a/src/sql/engine/join/ob_nested_loop_join_op.cpp b/src/sql/engine/join/ob_nested_loop_join_op.cpp
index 132f2139a5..50b5c91603 100644
--- a/src/sql/engine/join/ob_nested_loop_join_op.cpp
+++ b/src/sql/engine/join/ob_nested_loop_join_op.cpp
@@ -51,10 +51,6 @@ int ObNestedLoopJoinOp::inner_open()
     LOG_WARN("nlp_op child is null", KP(left_), KP(right_), K(ret));
   } else if (OB_FAIL(ObBasicNestedLoopJoinOp::inner_open())) {
     LOG_WARN("failed to open in base class", K(ret));
-  } else if (MY_SPEC.use_group_) {
-    if (OB_FAIL(open_right_child())) {
-      LOG_WARN("failed to open right child", K(ret));
-    }
   }
   return ret;
 }
diff --git a/src/sql/engine/ob_operator.cpp b/src/sql/engine/ob_operator.cpp
index 38b5f40148..be5d6d16bd 100644
--- a/src/sql/engine/ob_operator.cpp
+++ b/src/sql/engine/ob_operator.cpp
@@ -623,6 +623,7 @@ int ObOperator::get_next_row()
   } else if (OB_ITER_END == ret) {
     int tmp_ret = drain_exch();
     if (OB_SUCCESS != tmp_ret) {
+      ret = tmp_ret;
       LOG_WARN("drain exchange data failed", K(tmp_ret));
     }
     if (got_first_row_) {
diff --git a/src/sql/engine/ob_phy_operator.cpp b/src/sql/engine/ob_phy_operator.cpp
index 1f05d54ddf..aba86e8c72 100644
--- a/src/sql/engine/ob_phy_operator.cpp
+++ b/src/sql/engine/ob_phy_operator.cpp
@@ -486,6 +486,7 @@ int ObPhyOperator::get_next_row(ObExecContext& ctx, const ObNewRow*& row) const
   if (OB_ITER_END == ret && NULL != op_ctx) {
     int tmp_ret = drain_exch(ctx);
     if (OB_SUCCESS != tmp_ret) {
+      ret = tmp_ret;
       LOG_WARN("drain exchange data failed", K(tmp_ret));
     }
     if (op_ctx->got_first_row_) {