From 8666e5b03b4a5bbef6f64281b0ce67996a3cd26d Mon Sep 17 00:00:00 2001
From: wjhuang2016 <huangwenjun1997@gmail.com>
Date: Thu, 13 Aug 2020 17:24:55 +0800
Subject: [PATCH] done

Signed-off-by: wjhuang2016 <huangwenjun1997@gmail.com>
---
 planner/core/task.go | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/planner/core/task.go b/planner/core/task.go
index 9aa2a0c951b40..3ec6866098100 100644
--- a/planner/core/task.go
+++ b/planner/core/task.go
@@ -711,14 +711,6 @@ func finishCopTask(ctx sessionctx.Context, task task) task {
 	if !ok {
 		return task
 	}
-	if t.tablePlan != nil {
-		tp := t.tablePlan
-		for len(tp.Children()) > 0 {
-			tp = tp.Children()[0]
-		}
-		ts := tp.(*PhysicalTableScan)
-		ts.Columns = ExpandVirtualColumn(ts.Columns, ts.schema, ts.Table.Columns)
-	}
 	sessVars := ctx.GetSessionVars()
 	// copTasks are run in parallel, to make the estimated cost closer to execution time, we amortize
 	// the cost to cop iterator workers. According to `CopClient::Send`, the concurrency
@@ -729,6 +721,18 @@ func finishCopTask(ctx sessionctx.Context, task task) task {
 	// Network cost of transferring rows of table scan to TiDB.
 	if t.tablePlan != nil {
 		t.cst += t.count() * sessVars.NetworkFactor * t.tblColHists.GetAvgRowSize(ctx, t.tablePlan.Schema().Columns, false, false)
+
+		tp := t.tablePlan
+		for len(tp.Children()) > 0 {
+			if len(tp.Children()) == 1 {
+				tp = tp.Children()[0]
+			} else {
+				join := tp.(*PhysicalBroadCastJoin)
+				tp = join.children[1-join.InnerChildIdx]
+			}
+		}
+		ts := tp.(*PhysicalTableScan)
+		ts.Columns = ExpandVirtualColumn(ts.Columns, ts.schema, ts.Table.Columns)
 	}
 	t.cst /= copIterWorkers
 	newTask := &rootTask{