From ca6457ca230512ba3fc2a6ad45920267ed9f2474 Mon Sep 17 00:00:00 2001
From: Yuanjia Zhang <zhangyuanjia@pingcap.com>
Date: Thu, 18 Jul 2019 19:49:57 +0800
Subject: [PATCH 01/13] show memory in explain analyze

---
 executor/distsql.go           |  8 ++------
 executor/index_lookup_join.go |  1 -
 executor/join.go              |  2 --
 executor/merge_join.go        |  1 -
 executor/sort.go              |  1 -
 executor/table_reader.go      |  5 +----
 planner/core/common_plans.go  |  9 ++++++++-
 util/memory/tracker.go        | 32 ++++++++++++++++++++++----------
 8 files changed, 33 insertions(+), 26 deletions(-)

diff --git a/executor/distsql.go b/executor/distsql.go
index fcfbc110fcad3..8b521248b8357 100644
--- a/executor/distsql.go
+++ b/executor/distsql.go
@@ -261,8 +261,6 @@ func (e *IndexReaderExecutor) Open(ctx context.Context) error {
 	return e.open(ctx, kvRanges)
 }
 
-var indexReaderDistSQLTrackerLabel fmt.Stringer = stringutil.StringerStr("IndexReaderDistSQLTracker")
-
 func (e *IndexReaderExecutor) open(ctx context.Context, kvRanges []kv.KeyRange) error {
 	var err error
 	if e.corColInFilter {
@@ -284,7 +282,7 @@ func (e *IndexReaderExecutor) open(ctx context.Context, kvRanges []kv.KeyRange)
 		SetKeepOrder(e.keepOrder).
 		SetStreaming(e.streaming).
 		SetFromSessionVars(e.ctx.GetSessionVars()).
-		SetMemTracker(e.ctx, indexReaderDistSQLTrackerLabel).
+		SetMemTracker(e.ctx, e.id).
 		Build()
 	if err != nil {
 		e.feedback.Invalidate()
@@ -471,8 +469,6 @@ func (e *IndexLookUpExecutor) startIndexWorker(ctx context.Context, kvRanges []k
 	return nil
 }
 
-var tableWorkerLabel fmt.Stringer = stringutil.StringerStr("tableWorker")
-
 // startTableWorker launchs some background goroutines which pick tasks from workCh and execute the task.
 func (e *IndexLookUpExecutor) startTableWorker(ctx context.Context, workCh <-chan *lookupTableTask) {
 	lookupConcurrencyLimit := e.ctx.GetSessionVars().IndexLookupConcurrency
@@ -486,7 +482,7 @@ func (e *IndexLookUpExecutor) startTableWorker(ctx context.Context, workCh <-cha
 			keepOrder:      e.keepOrder,
 			handleIdx:      e.handleIdx,
 			isCheckOp:      e.isCheckOp,
-			memTracker:     memory.NewTracker(tableWorkerLabel, -1),
+			memTracker:     memory.NewTracker(stringutil.StringerStr(fmt.Sprintf("worker_%v", i)), -1),
 		}
 		worker.memTracker.AttachTo(e.memTracker)
 		ctx1, cancel := context.WithCancel(ctx)
diff --git a/executor/index_lookup_join.go b/executor/index_lookup_join.go
index 7f90e85303fe5..3ea1f62e7d6d3 100644
--- a/executor/index_lookup_join.go
+++ b/executor/index_lookup_join.go
@@ -650,7 +650,6 @@ func (e *IndexLookUpJoin) Close() error {
 		e.cancelFunc()
 	}
 	e.workerWg.Wait()
-	e.memTracker.Detach()
 	e.memTracker = nil
 	return e.children[0].Close()
 }
diff --git a/executor/join.go b/executor/join.go
index 12cd377271ade..d6f8e9042ca4a 100644
--- a/executor/join.go
+++ b/executor/join.go
@@ -134,7 +134,6 @@ func (e *HashJoinExec) Close() error {
 		e.outerChkResourceCh = nil
 		e.joinChkResourceCh = nil
 	}
-	e.memTracker.Detach()
 	e.memTracker = nil
 
 	err := e.baseExecutor.Close()
@@ -633,7 +632,6 @@ type NestedLoopApplyExec struct {
 func (e *NestedLoopApplyExec) Close() error {
 	e.innerRows = nil
 
-	e.memTracker.Detach()
 	e.memTracker = nil
 	return e.outerExec.Close()
 }
diff --git a/executor/merge_join.go b/executor/merge_join.go
index 9a7a09912d440..f7415d6bf1444 100644
--- a/executor/merge_join.go
+++ b/executor/merge_join.go
@@ -200,7 +200,6 @@ func (t *mergeJoinInnerTable) reallocReaderResult() {
 
 // Close implements the Executor Close interface.
 func (e *MergeJoinExec) Close() error {
-	e.memTracker.Detach()
 	e.childrenResults = nil
 	e.memTracker = nil
 
diff --git a/executor/sort.go b/executor/sort.go
index 4209dafd91d4c..aa895015b1eec 100644
--- a/executor/sort.go
+++ b/executor/sort.go
@@ -54,7 +54,6 @@ type SortExec struct {
 
 // Close implements the Executor Close interface.
 func (e *SortExec) Close() error {
-	e.memTracker.Detach()
 	e.memTracker = nil
 	return e.children[0].Close()
 }
diff --git a/executor/table_reader.go b/executor/table_reader.go
index 3f6bea659295a..26fba0b54f008 100644
--- a/executor/table_reader.go
+++ b/executor/table_reader.go
@@ -27,7 +27,6 @@ import (
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/chunk"
 	"github.com/pingcap/tidb/util/ranger"
-	"github.com/pingcap/tidb/util/stringutil"
 	"github.com/pingcap/tipb/go-tipb"
 )
 
@@ -148,8 +147,6 @@ func (e *TableReaderExecutor) Close() error {
 	return err
 }
 
-var tableReaderDistSQLTrackerLabel fmt.Stringer = stringutil.StringerStr("TableReaderDistSQLTracker")
-
 // buildResp first builds request and sends it to tikv using distsql.Select. It uses SelectResut returned by the callee
 // to fetch all results.
 func (e *TableReaderExecutor) buildResp(ctx context.Context, ranges []*ranger.Range) (distsql.SelectResult, error) {
@@ -160,7 +157,7 @@ func (e *TableReaderExecutor) buildResp(ctx context.Context, ranges []*ranger.Ra
 		SetKeepOrder(e.keepOrder).
 		SetStreaming(e.streaming).
 		SetFromSessionVars(e.ctx.GetSessionVars()).
-		SetMemTracker(e.ctx, tableReaderDistSQLTrackerLabel).
+		SetMemTracker(e.ctx, e.id).
 		Build()
 	if err != nil {
 		return nil, err
diff --git a/planner/core/common_plans.go b/planner/core/common_plans.go
index 96a33507287f2..17ce710ca3146 100644
--- a/planner/core/common_plans.go
+++ b/planner/core/common_plans.go
@@ -563,7 +563,7 @@ func (e *Explain) prepareSchema() error {
 	case ast.ExplainFormatROW:
 		retFields := []string{"id", "count", "task", "operator info"}
 		if e.Analyze {
-			retFields = append(retFields, "execution info")
+			retFields = append(retFields, "execution info", "memory")
 		}
 		schema := expression.NewSchema(make([]*expression.Column, 0, len(retFields))...)
 		for _, fieldName := range retFields {
@@ -643,6 +643,13 @@ func (e *Explain) prepareOperatorInfo(p PhysicalPlan, taskType string, indent st
 		} else {
 			row = append(row, "time:0ns, loops:0, rows:0")
 		}
+
+		tracker := e.ctx.GetSessionVars().StmtCtx.MemTracker.SearchTracker(p.ExplainID().String())
+		if tracker != nil {
+			row = append(row, tracker.BytesToString(tracker.MaxConsumed()))
+		} else {
+			row = append(row, "-")
+		}
 	}
 	e.Rows = append(e.Rows, row)
 }
diff --git a/util/memory/tracker.go b/util/memory/tracker.go
index befbab5ce3e76..07b5f7d850140 100644
--- a/util/memory/tracker.go
+++ b/util/memory/tracker.go
@@ -144,17 +144,13 @@ func (t *Tracker) Consume(bytes int64) {
 			rootExceed = tracker
 		}
 
-		if tracker.parent == nil {
-			// since we only need a total memory usage during execution,
-			// we only record max consumed bytes in root(statement-level) for performance.
-			for {
-				maxNow := atomic.LoadInt64(&tracker.maxConsumed)
-				consumed := atomic.LoadInt64(&tracker.bytesConsumed)
-				if consumed > maxNow && !atomic.CompareAndSwapInt64(&tracker.maxConsumed, maxNow, consumed) {
-					continue
-				}
-				break
+		for {
+			maxNow := atomic.LoadInt64(&tracker.maxConsumed)
+			consumed := atomic.LoadInt64(&tracker.bytesConsumed)
+			if consumed > maxNow && !atomic.CompareAndSwapInt64(&tracker.maxConsumed, maxNow, consumed) {
+				continue
 			}
+			break
 		}
 	}
 	if rootExceed != nil {
@@ -172,6 +168,21 @@ func (t *Tracker) MaxConsumed() int64 {
 	return atomic.LoadInt64(&t.maxConsumed)
 }
 
+// SearchTracker searches the specific tracker under this tracker.
+func (t *Tracker) SearchTracker(label string) *Tracker {
+	if t.label.String() == label {
+		return t
+	}
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	for _, child := range t.mu.children {
+		if result := child.SearchTracker(label); result != nil {
+			return result
+		}
+	}
+	return nil
+}
+
 // String returns the string representation of this Tracker tree.
 func (t *Tracker) String() string {
 	buffer := bytes.NewBufferString("\n")
@@ -185,6 +196,7 @@ func (t *Tracker) toString(indent string, buffer *bytes.Buffer) {
 		fmt.Fprintf(buffer, "%s  \"quota\": %s\n", indent, t.BytesToString(t.bytesLimit))
 	}
 	fmt.Fprintf(buffer, "%s  \"consumed\": %s\n", indent, t.BytesToString(t.BytesConsumed()))
+	fmt.Fprintf(buffer, "%s  \"max-consumed\": %s\n", indent, t.BytesToString(t.MaxConsumed()))
 
 	t.mu.Lock()
 	for i := range t.mu.children {

From 37d1be2a660805be1af71014fa38df6d6ff47990 Mon Sep 17 00:00:00 2001
From: Yuanjia Zhang <zhangyuanjia@pingcap.com>
Date: Thu, 18 Jul 2019 20:03:06 +0800
Subject: [PATCH 02/13] format

---
 util/memory/tracker.go | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/util/memory/tracker.go b/util/memory/tracker.go
index 07b5f7d850140..5d44e7c3f3dce 100644
--- a/util/memory/tracker.go
+++ b/util/memory/tracker.go
@@ -212,17 +212,17 @@ func (t *Tracker) toString(indent string, buffer *bytes.Buffer) {
 func (t *Tracker) BytesToString(numBytes int64) string {
 	GB := float64(numBytes) / float64(1<<30)
 	if GB > 1 {
-		return fmt.Sprintf("%v GB", GB)
+		return fmt.Sprintf("%.3f GB", GB)
 	}
 
 	MB := float64(numBytes) / float64(1<<20)
 	if MB > 1 {
-		return fmt.Sprintf("%v MB", MB)
+		return fmt.Sprintf("%.3f MB", MB)
 	}
 
 	KB := float64(numBytes) / float64(1<<10)
 	if KB > 1 {
-		return fmt.Sprintf("%v KB", KB)
+		return fmt.Sprintf("%.3f KB", KB)
 	}
 
 	return fmt.Sprintf("%v Bytes", numBytes)

From ca0beecca30d92a8634f40ebd6aca8ca0465a500 Mon Sep 17 00:00:00 2001
From: Yuanjia Zhang <zhangyuanjia@pingcap.com>
Date: Thu, 18 Jul 2019 20:31:41 +0800
Subject: [PATCH 03/13] add UT

---
 executor/explain_test.go | 48 ++++++++++++++++++++++++++++++++++++++++
 util/memory/tracker.go   |  1 -
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/executor/explain_test.go b/executor/explain_test.go
index c36179a283e52..87fd715e12f2e 100644
--- a/executor/explain_test.go
+++ b/executor/explain_test.go
@@ -19,6 +19,7 @@ import (
 	plannercore "github.com/pingcap/tidb/planner/core"
 	"github.com/pingcap/tidb/session"
 	"github.com/pingcap/tidb/util/testkit"
+	"strings"
 )
 
 func (s *testSuite1) TestExplainPriviliges(c *C) {
@@ -74,3 +75,50 @@ func (s *testSuite1) TestExplainWrite(c *C) {
 	tk.MustExec("explain analyze insert into t select 1")
 	tk.MustQuery("select * from t order by a").Check(testkit.Rows("1", "2"))
 }
+
+func (s *testSuite1) TestExplainAnalyzeMemory(c *C) {
+	tk := testkit.NewTestKitWithInit(c, s.store)
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t (v int, k int, key(k))")
+	tk.MustExec("insert into t values (1, 1), (1, 1), (1, 1), (1, 1), (1, 1)")
+
+	s.checkMemoryInfo(c, tk, "explain analyze select * from t order by v")
+	s.checkMemoryInfo(c, tk, "explain analyze select * from t order by v limit 5")
+	s.checkMemoryInfo(c, tk, "explain analyze select /*+ TIDB_HJ(t1, t2) */ t1.k from t t1, t t2 where t1.v = t2.v+1")
+	s.checkMemoryInfo(c, tk, "explain analyze select /*+ TIDB_SMJ(t1, t2) */ t1.k from t t1, t t2 where t1.k = t2.k+1")
+	s.checkMemoryInfo(c, tk, "explain analyze select /*+ TIDB_INLJ(t1, t2) */ t1.k from t t1, t t2 where t1.k = t2.k and t1.v=1")
+	s.checkMemoryInfo(c, tk, "explain analyze select sum(k) from t group by v")
+	s.checkMemoryInfo(c, tk, "explain analyze select sum(v) from t group by k")
+	s.checkMemoryInfo(c, tk, "explain analyze select * from t")
+	s.checkMemoryInfo(c, tk, "explain analyze select k from t use index(k)")
+	s.checkMemoryInfo(c, tk, "explain analyze select * from t use index(k)")
+}
+
+func (s *testSuite1) checkMemoryInfo(c *C, tk *testkit.TestKit, sql string) {
+	memCol := 5
+	ops := []string{"Join", "MergeAgg", "Reader", "Top", "Sort"}
+	rows := tk.MustQuery(sql).Rows()
+	for _, row := range rows {
+		strs := make([]string, len(row))
+		for i, c := range row {
+			strs[i] = c.(string)
+		}
+		if strings.Contains(strs[2], "cop") {
+			continue
+		}
+
+		shouldHasMem := false
+		for _, op := range ops {
+			if strings.Contains(strs[0], op) {
+				shouldHasMem = true
+				break
+			}
+		}
+
+		if shouldHasMem {
+			c.Assert(strs[memCol], Not(Equals), "-")
+		} else {
+			c.Assert(strs[memCol], Equals, "-")
+		}
+	}
+}
diff --git a/util/memory/tracker.go b/util/memory/tracker.go
index 5d44e7c3f3dce..0b3eba17bb815 100644
--- a/util/memory/tracker.go
+++ b/util/memory/tracker.go
@@ -196,7 +196,6 @@ func (t *Tracker) toString(indent string, buffer *bytes.Buffer) {
 		fmt.Fprintf(buffer, "%s  \"quota\": %s\n", indent, t.BytesToString(t.bytesLimit))
 	}
 	fmt.Fprintf(buffer, "%s  \"consumed\": %s\n", indent, t.BytesToString(t.BytesConsumed()))
-	fmt.Fprintf(buffer, "%s  \"max-consumed\": %s\n", indent, t.BytesToString(t.MaxConsumed()))
 
 	t.mu.Lock()
 	for i := range t.mu.children {

From 8d5f9c2f22fb7260bc4333b0c482247d6804238d Mon Sep 17 00:00:00 2001
From: Yuanjia Zhang <zhangyuanjia@pingcap.com>
Date: Thu, 18 Jul 2019 20:34:25 +0800
Subject: [PATCH 04/13] update UT

---
 executor/explain_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/executor/explain_test.go b/executor/explain_test.go
index 87fd715e12f2e..75ec67e472d08 100644
--- a/executor/explain_test.go
+++ b/executor/explain_test.go
@@ -96,7 +96,7 @@ func (s *testSuite1) TestExplainAnalyzeMemory(c *C) {
 
 func (s *testSuite1) checkMemoryInfo(c *C, tk *testkit.TestKit, sql string) {
 	memCol := 5
-	ops := []string{"Join", "MergeAgg", "Reader", "Top", "Sort"}
+	ops := []string{"Join", "Reader", "Top", "Sort"}
 	rows := tk.MustQuery(sql).Rows()
 	for _, row := range rows {
 		strs := make([]string, len(row))

From 003b73823f3204e677a54fa3d19524d3b8c24b31 Mon Sep 17 00:00:00 2001
From: Yuanjia Zhang <zhangyuanjia@pingcap.com>
Date: Thu, 18 Jul 2019 20:48:28 +0800
Subject: [PATCH 05/13] fix UT

---
 planner/core/cbo_test.go | 4 ++--
 util/memory/tracker.go   | 6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/planner/core/cbo_test.go b/planner/core/cbo_test.go
index cdce14d6e8f73..222512c2419c0 100644
--- a/planner/core/cbo_test.go
+++ b/planner/core/cbo_test.go
@@ -80,7 +80,7 @@ func (s *testAnalyzeSuite) TestExplainAnalyze(c *C) {
 	rs := tk.MustQuery("explain analyze select t1.a, t1.b, sum(t1.c) from t1 join t2 on t1.a = t2.b where t1.a > 1")
 	c.Assert(len(rs.Rows()), Equals, 10)
 	for _, row := range rs.Rows() {
-		c.Assert(len(row), Equals, 5)
+		c.Assert(len(row), Equals, 6)
 		execInfo := row[4].(string)
 		c.Assert(strings.Contains(execInfo, "time"), Equals, true)
 		c.Assert(strings.Contains(execInfo, "loops"), Equals, true)
@@ -977,7 +977,7 @@ func (s *testAnalyzeSuite) TestIssue9805(c *C) {
 	c.Assert(rs.Rows(), HasLen, 10)
 	hasIndexLookUp12 := false
 	for _, row := range rs.Rows() {
-		c.Assert(row, HasLen, 5)
+		c.Assert(row, HasLen, 6)
 		if strings.HasSuffix(row[0].(string), "IndexLookUp_12") {
 			hasIndexLookUp12 = true
 			c.Assert(row[4], Equals, "time:0ns, loops:0, rows:0")
diff --git a/util/memory/tracker.go b/util/memory/tracker.go
index 0b3eba17bb815..56761f4f4c700 100644
--- a/util/memory/tracker.go
+++ b/util/memory/tracker.go
@@ -211,17 +211,17 @@ func (t *Tracker) toString(indent string, buffer *bytes.Buffer) {
 func (t *Tracker) BytesToString(numBytes int64) string {
 	GB := float64(numBytes) / float64(1<<30)
 	if GB > 1 {
-		return fmt.Sprintf("%.3f GB", GB)
+		return fmt.Sprintf("%v GB", GB)
 	}
 
 	MB := float64(numBytes) / float64(1<<20)
 	if MB > 1 {
-		return fmt.Sprintf("%.3f MB", MB)
+		return fmt.Sprintf("%v MB", MB)
 	}
 
 	KB := float64(numBytes) / float64(1<<10)
 	if KB > 1 {
-		return fmt.Sprintf("%.3f KB", KB)
+		return fmt.Sprintf("%v KB", KB)
 	}
 
 	return fmt.Sprintf("%v Bytes", numBytes)

From bcd46138f6d8860349ba9df6c59d2078516d128a Mon Sep 17 00:00:00 2001
From: Yuanjia Zhang <zhangyuanjia@pingcap.com>
Date: Thu, 18 Jul 2019 20:52:04 +0800
Subject: [PATCH 06/13] format

---
 executor/explain_test.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/executor/explain_test.go b/executor/explain_test.go
index 75ec67e472d08..ae00b402a4284 100644
--- a/executor/explain_test.go
+++ b/executor/explain_test.go
@@ -14,12 +14,13 @@
 package executor_test
 
 import (
+	"strings"
+	
 	. "github.com/pingcap/check"
 	"github.com/pingcap/parser/auth"
 	plannercore "github.com/pingcap/tidb/planner/core"
 	"github.com/pingcap/tidb/session"
 	"github.com/pingcap/tidb/util/testkit"
-	"strings"
 )
 
 func (s *testSuite1) TestExplainPriviliges(c *C) {

From 6f2c5a2ad12b35813f55046050457bc58ca5c4f2 Mon Sep 17 00:00:00 2001
From: Yuanjia Zhang <zhangyuanjia@pingcap.com>
Date: Fri, 19 Jul 2019 13:18:15 +0800
Subject: [PATCH 07/13] remove Tracker.Detach

---
 executor/distsql.go           | 1 -
 executor/index_lookup_join.go | 3 ---
 util/memory/tracker.go        | 5 -----
 3 files changed, 9 deletions(-)

diff --git a/executor/distsql.go b/executor/distsql.go
index 8b521248b8357..e20fb92c5fba9 100644
--- a/executor/distsql.go
+++ b/executor/distsql.go
@@ -527,7 +527,6 @@ func (e *IndexLookUpExecutor) Close() error {
 	e.tblWorkerWg.Wait()
 	e.finished = nil
 	e.workerStarted = false
-	e.memTracker.Detach()
 	e.memTracker = nil
 	if e.runtimeStats != nil {
 		copStats := e.ctx.GetSessionVars().StmtCtx.RuntimeStatsColl.GetRootStats(e.idxPlans[0].ExplainID().String())
diff --git a/executor/index_lookup_join.go b/executor/index_lookup_join.go
index 3ea1f62e7d6d3..5f596a69b168d 100644
--- a/executor/index_lookup_join.go
+++ b/executor/index_lookup_join.go
@@ -295,9 +295,6 @@ func (e *IndexLookUpJoin) getFinishedTask(ctx context.Context) (*lookUpJoinTask,
 		return nil, nil
 	}
 
-	if e.task != nil {
-		e.task.memTracker.Detach()
-	}
 	e.task = task
 	return task, nil
 }
diff --git a/util/memory/tracker.go b/util/memory/tracker.go
index 56761f4f4c700..3b935360f0fce 100644
--- a/util/memory/tracker.go
+++ b/util/memory/tracker.go
@@ -87,11 +87,6 @@ func (t *Tracker) AttachTo(parent *Tracker) {
 	t.parent.Consume(t.BytesConsumed())
 }
 
-// Detach detaches this Tracker from its parent.
-func (t *Tracker) Detach() {
-	t.parent.remove(t)
-}
-
 func (t *Tracker) remove(oldChild *Tracker) {
 	t.mu.Lock()
 	defer t.mu.Unlock()

From 95c8e49a40296452108b726d85da61f56e0158df Mon Sep 17 00:00:00 2001
From: Yuanjia Zhang <zhangyuanjia@pingcap.com>
Date: Fri, 19 Jul 2019 13:31:09 +0800
Subject: [PATCH 08/13] fixup

---
 distsql/distsql_test.go    | 1 -
 distsql/request_builder.go | 8 ++------
 executor/distsql.go        | 9 +++++++--
 executor/table_reader.go   | 8 +++++++-
 4 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/distsql/distsql_test.go b/distsql/distsql_test.go
index 470f2e78bab67..a4bc06661cca3 100644
--- a/distsql/distsql_test.go
+++ b/distsql/distsql_test.go
@@ -42,7 +42,6 @@ func (s *testSuite) createSelectNormal(batch, totalRows int, c *C, planIDs []str
 		SetDesc(false).
 		SetKeepOrder(false).
 		SetFromSessionVars(variable.NewSessionVars()).
-		SetMemTracker(s.sctx, stringutil.StringerStr("testSuite.createSelectNormal")).
 		Build()
 	c.Assert(err, IsNil)
 
diff --git a/distsql/request_builder.go b/distsql/request_builder.go
index 9e1ef6c624f05..10c91e93598d1 100644
--- a/distsql/request_builder.go
+++ b/distsql/request_builder.go
@@ -14,12 +14,10 @@
 package distsql
 
 import (
-	"fmt"
 	"math"
 
 	"github.com/pingcap/parser/mysql"
 	"github.com/pingcap/tidb/kv"
-	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/sessionctx/stmtctx"
 	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/statistics"
@@ -44,10 +42,8 @@ func (builder *RequestBuilder) Build() (*kv.Request, error) {
 }
 
 // SetMemTracker sets a memTracker for this request.
-func (builder *RequestBuilder) SetMemTracker(sctx sessionctx.Context, label fmt.Stringer) *RequestBuilder {
-	t := memory.NewTracker(label, sctx.GetSessionVars().MemQuotaDistSQL)
-	t.AttachTo(sctx.GetSessionVars().StmtCtx.MemTracker)
-	builder.Request.MemTracker = t
+func (builder *RequestBuilder) SetMemTracker(tracker *memory.Tracker) *RequestBuilder {
+	builder.Request.MemTracker = tracker
 	return builder
 }
 
diff --git a/executor/distsql.go b/executor/distsql.go
index e20fb92c5fba9..f2a6c393f2233 100644
--- a/executor/distsql.go
+++ b/executor/distsql.go
@@ -220,6 +220,8 @@ type IndexReaderExecutor struct {
 	colLens        []int
 	plans          []plannercore.PhysicalPlan
 
+	memTracker *memory.Tracker
+
 	selectResultHook // for testing
 }
 
@@ -275,6 +277,7 @@ func (e *IndexReaderExecutor) open(ctx context.Context, kvRanges []kv.KeyRange)
 		e.dagPB.CollectExecutionSummaries = &collExec
 	}
 
+	e.memTracker = memory.NewTracker(e.id, e.ctx.GetSessionVars().MemQuotaDistSQL)
 	var builder distsql.RequestBuilder
 	kvReq, err := builder.SetKeyRanges(kvRanges).
 		SetDAGRequest(e.dagPB).
@@ -282,7 +285,7 @@ func (e *IndexReaderExecutor) open(ctx context.Context, kvRanges []kv.KeyRange)
 		SetKeepOrder(e.keepOrder).
 		SetStreaming(e.streaming).
 		SetFromSessionVars(e.ctx.GetSessionVars()).
-		SetMemTracker(e.ctx, e.id).
+		SetMemTracker(e.memTracker).
 		Build()
 	if err != nil {
 		e.feedback.Invalidate()
@@ -413,6 +416,8 @@ func (e *IndexLookUpExecutor) startIndexWorker(ctx context.Context, kvRanges []k
 		e.dagPB.CollectExecutionSummaries = &collExec
 	}
 
+	tracker := memory.NewTracker(stringutil.StringerStr("InnerWorker"), e.ctx.GetSessionVars().MemQuotaDistSQL)
+	tracker.AttachTo(e.memTracker)
 	var builder distsql.RequestBuilder
 	kvReq, err := builder.SetKeyRanges(kvRanges).
 		SetDAGRequest(e.dagPB).
@@ -420,7 +425,7 @@ func (e *IndexLookUpExecutor) startIndexWorker(ctx context.Context, kvRanges []k
 		SetKeepOrder(e.keepOrder).
 		SetStreaming(e.indexStreaming).
 		SetFromSessionVars(e.ctx.GetSessionVars()).
-		SetMemTracker(e.ctx, indexLookupDistSQLTrackerLabel).
+		SetMemTracker(tracker).
 		Build()
 	if err != nil {
 		return err
diff --git a/executor/table_reader.go b/executor/table_reader.go
index 26fba0b54f008..8f80c0bced49c 100644
--- a/executor/table_reader.go
+++ b/executor/table_reader.go
@@ -16,6 +16,7 @@ package executor
 import (
 	"context"
 	"fmt"
+	"github.com/pingcap/tidb/util/memory"
 
 	"github.com/pingcap/parser/model"
 	"github.com/pingcap/tidb/distsql"
@@ -71,11 +72,16 @@ type TableReaderExecutor struct {
 	corColInAccess bool
 	plans          []plannercore.PhysicalPlan
 
+	memTracker *memory.Tracker
+
 	selectResultHook // for testing
 }
 
 // Open initialzes necessary variables for using this executor.
 func (e *TableReaderExecutor) Open(ctx context.Context) error {
+	e.memTracker = memory.NewTracker(e.id, e.ctx.GetSessionVars().MemQuotaDistSQL)
+	e.memTracker.AttachTo(e.ctx.GetSessionVars().StmtCtx.MemTracker)
+
 	var err error
 	if e.corColInFilter {
 		e.dagPB.Executors, _, err = constructDistExec(e.ctx, e.plans)
@@ -157,7 +163,7 @@ func (e *TableReaderExecutor) buildResp(ctx context.Context, ranges []*ranger.Ra
 		SetKeepOrder(e.keepOrder).
 		SetStreaming(e.streaming).
 		SetFromSessionVars(e.ctx.GetSessionVars()).
-		SetMemTracker(e.ctx, e.id).
+		SetMemTracker(e.memTracker).
 		Build()
 	if err != nil {
 		return nil, err

From ce45ed5b8113467a394c9d56fea974877efc2022 Mon Sep 17 00:00:00 2001
From: Yuanjia Zhang <zhangyuanjia@pingcap.com>
Date: Fri, 19 Jul 2019 14:00:36 +0800
Subject: [PATCH 09/13] fix UT

---
 executor/distsql.go      | 1 +
 executor/explain_test.go | 4 ++--
 executor/table_reader.go | 2 +-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/executor/distsql.go b/executor/distsql.go
index f2a6c393f2233..29aa9657e6b75 100644
--- a/executor/distsql.go
+++ b/executor/distsql.go
@@ -278,6 +278,7 @@ func (e *IndexReaderExecutor) open(ctx context.Context, kvRanges []kv.KeyRange)
 	}
 
 	e.memTracker = memory.NewTracker(e.id, e.ctx.GetSessionVars().MemQuotaDistSQL)
+	e.memTracker.AttachTo(e.ctx.GetSessionVars().StmtCtx.MemTracker)
 	var builder distsql.RequestBuilder
 	kvReq, err := builder.SetKeyRanges(kvRanges).
 		SetDAGRequest(e.dagPB).
diff --git a/executor/explain_test.go b/executor/explain_test.go
index ae00b402a4284..277cf3df96af5 100644
--- a/executor/explain_test.go
+++ b/executor/explain_test.go
@@ -15,7 +15,7 @@ package executor_test
 
 import (
 	"strings"
-	
+
 	. "github.com/pingcap/check"
 	"github.com/pingcap/parser/auth"
 	plannercore "github.com/pingcap/tidb/planner/core"
@@ -97,7 +97,7 @@ func (s *testSuite1) TestExplainAnalyzeMemory(c *C) {
 
 func (s *testSuite1) checkMemoryInfo(c *C, tk *testkit.TestKit, sql string) {
 	memCol := 5
-	ops := []string{"Join", "Reader", "Top", "Sort"}
+	ops := []string{"Join", "Reader", "Top", "Sort", "LookUp"}
 	rows := tk.MustQuery(sql).Rows()
 	for _, row := range rows {
 		strs := make([]string, len(row))
diff --git a/executor/table_reader.go b/executor/table_reader.go
index 8f80c0bced49c..019957e678247 100644
--- a/executor/table_reader.go
+++ b/executor/table_reader.go
@@ -16,7 +16,6 @@ package executor
 import (
 	"context"
 	"fmt"
-	"github.com/pingcap/tidb/util/memory"
 
 	"github.com/pingcap/parser/model"
 	"github.com/pingcap/tidb/distsql"
@@ -27,6 +26,7 @@ import (
 	"github.com/pingcap/tidb/table"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/chunk"
+	"github.com/pingcap/tidb/util/memory"
 	"github.com/pingcap/tidb/util/ranger"
 	"github.com/pingcap/tipb/go-tipb"
 )

From 61e9f2b95e988e8f6f1d3fe925ba620544b7613a Mon Sep 17 00:00:00 2001
From: Yuanjia Zhang <zhangyuanjia@pingcap.com>
Date: Fri, 19 Jul 2019 14:29:03 +0800
Subject: [PATCH 10/13] fix CI

---
 distsql/distsql_test.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/distsql/distsql_test.go b/distsql/distsql_test.go
index a4bc06661cca3..4a145717d0fce 100644
--- a/distsql/distsql_test.go
+++ b/distsql/distsql_test.go
@@ -32,6 +32,7 @@ import (
 	"github.com/pingcap/tidb/util/chunk"
 	"github.com/pingcap/tidb/util/codec"
 	"github.com/pingcap/tidb/util/execdetails"
+	"github.com/pingcap/tidb/util/memory"
 	"github.com/pingcap/tidb/util/stringutil"
 	"github.com/pingcap/tipb/go-tipb"
 )
@@ -42,6 +43,8 @@ func (s *testSuite) createSelectNormal(batch, totalRows int, c *C, planIDs []str
 		SetDesc(false).
 		SetKeepOrder(false).
 		SetFromSessionVars(variable.NewSessionVars()).
+		SetMemTracker(memory.NewTracker(stringutil.StringerStr("testSuite.createSelectNormal"),
+			s.sctx.GetSessionVars().MemQuotaDistSQL)).
 		Build()
 	c.Assert(err, IsNil)
 

From e7288f4d32c8744e1b765a2d26544019d8d0c381 Mon Sep 17 00:00:00 2001
From: Yuanjia Zhang <zhangyuanjia@pingcap.com>
Date: Fri, 19 Jul 2019 15:46:50 +0800
Subject: [PATCH 11/13] address comments

---
 executor/distsql.go          | 5 +++--
 executor/explain_test.go     | 4 ++--
 planner/core/common_plans.go | 2 +-
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/executor/distsql.go b/executor/distsql.go
index 29aa9657e6b75..2f09acddf19ca 100644
--- a/executor/distsql.go
+++ b/executor/distsql.go
@@ -417,7 +417,7 @@ func (e *IndexLookUpExecutor) startIndexWorker(ctx context.Context, kvRanges []k
 		e.dagPB.CollectExecutionSummaries = &collExec
 	}
 
-	tracker := memory.NewTracker(stringutil.StringerStr("InnerWorker"), e.ctx.GetSessionVars().MemQuotaDistSQL)
+	tracker := memory.NewTracker(stringutil.StringerStr("InnerWorker"), e.ctx.GetSessionVars().MemQuotaIndexLookupReader)
 	tracker.AttachTo(e.memTracker)
 	var builder distsql.RequestBuilder
 	kvReq, err := builder.SetKeyRanges(kvRanges).
@@ -488,7 +488,8 @@ func (e *IndexLookUpExecutor) startTableWorker(ctx context.Context, workCh <-cha
 			keepOrder:      e.keepOrder,
 			handleIdx:      e.handleIdx,
 			isCheckOp:      e.isCheckOp,
-			memTracker:     memory.NewTracker(stringutil.StringerStr(fmt.Sprintf("worker_%v", i)), -1),
+			memTracker: memory.NewTracker(stringutil.StringerStr(fmt.Sprintf("worker_%v", i)),
+				e.ctx.GetSessionVars().MemQuotaIndexLookupReader),
 		}
 		worker.memTracker.AttachTo(e.memTracker)
 		ctx1, cancel := context.WithCancel(ctx)
diff --git a/executor/explain_test.go b/executor/explain_test.go
index 277cf3df96af5..47c634f3f454e 100644
--- a/executor/explain_test.go
+++ b/executor/explain_test.go
@@ -117,9 +117,9 @@ func (s *testSuite1) checkMemoryInfo(c *C, tk *testkit.TestKit, sql string) {
 		}
 
 		if shouldHasMem {
-			c.Assert(strs[memCol], Not(Equals), "-")
+			c.Assert(strs[memCol], Not(Equals), "N/A")
 		} else {
-			c.Assert(strs[memCol], Equals, "-")
+			c.Assert(strs[memCol], Equals, "N/A")
 		}
 	}
 }
diff --git a/planner/core/common_plans.go b/planner/core/common_plans.go
index 17ce710ca3146..c43f03bf67b50 100644
--- a/planner/core/common_plans.go
+++ b/planner/core/common_plans.go
@@ -648,7 +648,7 @@ func (e *Explain) prepareOperatorInfo(p PhysicalPlan, taskType string, indent st
 		if tracker != nil {
 			row = append(row, tracker.BytesToString(tracker.MaxConsumed()))
 		} else {
-			row = append(row, "-")
+			row = append(row, "N/A")
 		}
 	}
 	e.Rows = append(e.Rows, row)

From 13efd9243360788e7cb0be516e7d6ca743e50ef5 Mon Sep 17 00:00:00 2001
From: Yuanjia Zhang <zhangyuanjia@pingcap.com>
Date: Tue, 23 Jul 2019 21:02:01 +0800
Subject: [PATCH 12/13] rename tacker name

---
 executor/distsql.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/executor/distsql.go b/executor/distsql.go
index 2f09acddf19ca..e00b3f7177cda 100644
--- a/executor/distsql.go
+++ b/executor/distsql.go
@@ -417,7 +417,7 @@ func (e *IndexLookUpExecutor) startIndexWorker(ctx context.Context, kvRanges []k
 		e.dagPB.CollectExecutionSummaries = &collExec
 	}
 
-	tracker := memory.NewTracker(stringutil.StringerStr("InnerWorker"), e.ctx.GetSessionVars().MemQuotaIndexLookupReader)
+	tracker := memory.NewTracker(stringutil.StringerStr("IndexWorker"), e.ctx.GetSessionVars().MemQuotaIndexLookupReader)
 	tracker.AttachTo(e.memTracker)
 	var builder distsql.RequestBuilder
 	kvReq, err := builder.SetKeyRanges(kvRanges).
@@ -488,7 +488,7 @@ func (e *IndexLookUpExecutor) startTableWorker(ctx context.Context, workCh <-cha
 			keepOrder:      e.keepOrder,
 			handleIdx:      e.handleIdx,
 			isCheckOp:      e.isCheckOp,
-			memTracker: memory.NewTracker(stringutil.StringerStr(fmt.Sprintf("worker_%v", i)),
+			memTracker: memory.NewTracker(stringutil.StringerStr(fmt.Sprintf("TableWorker_%v", i)),
 				e.ctx.GetSessionVars().MemQuotaIndexLookupReader),
 		}
 		worker.memTracker.AttachTo(e.memTracker)

From f276b088b23c7785efe96d09d5930c07d1c5d178 Mon Sep 17 00:00:00 2001
From: Yuanjia Zhang <zhangyuanjia@pingcap.com>
Date: Tue, 23 Jul 2019 21:04:01 +0800
Subject: [PATCH 13/13] address comments

---
 executor/distsql.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/executor/distsql.go b/executor/distsql.go
index e00b3f7177cda..c4cf91124d696 100644
--- a/executor/distsql.go
+++ b/executor/distsql.go
@@ -19,6 +19,7 @@ import (
 	"math"
 	"runtime"
 	"sort"
+	"strconv"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -488,7 +489,7 @@ func (e *IndexLookUpExecutor) startTableWorker(ctx context.Context, workCh <-cha
 			keepOrder:      e.keepOrder,
 			handleIdx:      e.handleIdx,
 			isCheckOp:      e.isCheckOp,
-			memTracker: memory.NewTracker(stringutil.StringerStr(fmt.Sprintf("TableWorker_%v", i)),
+			memTracker: memory.NewTracker(stringutil.MemoizeStr(func() string { return "TableWorker_" + strconv.Itoa(i) }),
 				e.ctx.GetSessionVars().MemQuotaIndexLookupReader),
 		}
 		worker.memTracker.AttachTo(e.memTracker)