planner,executor: support global index for IndexScan and IndexLookUpReader

distsql/request_builder.go

@@ -82,6 +82,13 @@ func (builder *RequestBuilder) SetTableHandles(tid int64, handles []kv.Handle) *
 	return builder
 }
 
+// SetPartitionsAndHandles sets "KeyRanges" for "kv.Request" by converting ParitionHandles to KeyRanges.
+// handles in slice must be kv.PartitionHandle.
+func (builder *RequestBuilder) SetPartitionsAndHandles(handles []kv.Handle) *RequestBuilder {
+	builder.Request.KeyRanges = PartitionHandlesToKVRanges(handles)
+	return builder
+}
+
 const estimatedRegionRowCount = 100000
 
 // SetDAGRequest sets the request type to "ReqTypeDAG" and construct request data.
@@ -299,6 +306,44 @@ func TableHandlesToKVRanges(tid int64, handles []kv.Handle) []kv.KeyRange {
 	return krs
 }
 
+// PartitionHandlesToKVRanges convert ParitionHandles to kv ranges.
+// Handle in slices must be kv.PartitionHandle
+func PartitionHandlesToKVRanges(handles []kv.Handle) []kv.KeyRange {
+	krs := make([]kv.KeyRange, 0, len(handles))
+	i := 0
+	for i < len(handles) {
+		ph := handles[i].(kv.PartitionHandle)
+		h := ph.Handle
+		pid := ph.PartitionID
+		if commonHandle, ok := h.(*kv.CommonHandle); ok {
+			ran := kv.KeyRange{
+				StartKey: tablecodec.EncodeRowKey(pid, commonHandle.Encoded()),
+				EndKey:   tablecodec.EncodeRowKey(pid, append(commonHandle.Encoded(), 0)),
+			}
+			krs = append(krs, ran)
+			i++
+			continue
+		}
+		j := i + 1
+		for ; j < len(handles) && handles[j-1].IntValue() != math.MaxInt64; j++ {
+			if handles[j].IntValue() != handles[j-1].IntValue()+1 {
+				break
+			}
+			if handles[j].(kv.PartitionHandle).PartitionID != pid {
+				break
+			}
+		}
+		low := codec.EncodeInt(nil, handles[i].IntValue())
+		high := codec.EncodeInt(nil, handles[j-1].IntValue())
+		high = kv.Key(high).PrefixNext()
+		startKey := tablecodec.EncodeRowKey(pid, low)
+		endKey := tablecodec.EncodeRowKey(pid, high)
+		krs = append(krs, kv.KeyRange{StartKey: startKey, EndKey: endKey})
+		i = j
+	}
+	return krs
+}
+
 // IndexRangesToKVRanges converts index ranges to "KeyRange".
 func IndexRangesToKVRanges(sc *stmtctx.StatementContext, tid, idxID int64, ranges []*ranger.Range, fb *statistics.QueryFeedback) ([]kv.KeyRange, error) {
 	if fb == nil || fb.Hist == nil {

executor/builder.go

@@ -2670,6 +2670,10 @@ func (b *executorBuilder) buildIndexReader(v *plannercore.PhysicalIndexReader) E
 		return ret
 	}
 
+	if is.Index.Global {
+		return ret
+	}
+
 	nextPartition := nextPartitionForIndexReader{exec: ret}
 	exec, err := buildPartitionTable(b, is.Table, &v.PartitionInfo, ret, nextPartition)
 	if err != nil {
@@ -2713,7 +2717,17 @@ func buildIndexReq(b *executorBuilder, schemaLen, handleLen int, plans []planner
 
 func buildNoRangeIndexLookUpReader(b *executorBuilder, v *plannercore.PhysicalIndexLookUpReader) (*IndexLookUpExecutor, error) {
 	is := v.IndexPlans[0].(*plannercore.PhysicalIndexScan)
-	indexReq, indexStreaming, err := buildIndexReq(b, len(is.Index.Columns), len(v.CommonHandleCols), v.IndexPlans)
+	var handleLen int
+	if len(v.CommonHandleCols) != 0 {
+		handleLen = len(v.CommonHandleCols)
+	} else {
+		handleLen = 1
+	}
+	if is.Index.Global {
+		// Should output pid col.
+		handleLen++
+	}
+	indexReq, indexStreaming, err := buildIndexReq(b, len(is.Index.Columns), handleLen, v.IndexPlans)
 	if err != nil {
 		return nil, err
 	}
@@ -2806,6 +2820,10 @@ func (b *executorBuilder) buildIndexLookUpReader(v *plannercore.PhysicalIndexLoo
 		return ret
 	}
 
+	if is.Index.Global {
+		return ret
+	}
+
 	nextPartition := nextPartitionForIndexLookUp{exec: ret}
 	exec, err := buildPartitionTable(b, ts.Table, &v.PartitionInfo, ret, nextPartition)
 	if err != nil {
@@ -3100,7 +3118,11 @@ func (builder *dataReaderBuilder) buildTableReaderFromHandles(ctx context.Contex
 		})
 	}
 	var b distsql.RequestBuilder
-	b.SetTableHandles(getPhysicalTableID(e.table), handles)
+	if _, ok := handles[0].(kv.PartitionHandle); ok {
+		b.SetPartitionsAndHandles(handles)
+	} else {
+		b.SetTableHandles(getPhysicalTableID(e.table), handles)
+	}
 	return builder.buildTableReaderBase(ctx, e, b)
 }
 

executor/distsql.go

@@ -459,6 +459,9 @@ func (e *IndexLookUpExecutor) getRetTpsByHandle() []*types.FieldType {
 	} else {
 		tps = []*types.FieldType{types.NewFieldType(mysql.TypeLonglong)}
 	}
+	if e.index.Global {
+		tps = append(tps, types.NewFieldType(mysql.TypeLonglong))
+	}
 	if e.checkIndexValue != nil {
 		tps = e.idxColTps
 	}
@@ -714,11 +717,15 @@ func (w *indexWorker) fetchHandles(ctx context.Context, result distsql.SelectRes
 func (w *indexWorker) extractTaskHandles(ctx context.Context, chk *chunk.Chunk, idxResult distsql.SelectResult, count uint64) (
 	handles []kv.Handle, retChk *chunk.Chunk, scannedKeys uint64, err error) {
 	var handleOffset []int
+	numColsWithoutPid := chk.NumCols()
+	if w.idxLookup.index.Global {
+		numColsWithoutPid = numColsWithoutPid - 1
+	}
 	for i := range w.idxLookup.handleCols {
-		handleOffset = append(handleOffset, chk.NumCols()-len(w.idxLookup.handleCols)+i)
+		handleOffset = append(handleOffset, numColsWithoutPid-len(w.idxLookup.handleCols)+i)
 	}
 	if len(handleOffset) == 0 {
-		handleOffset = []int{chk.NumCols() - 1}
+		handleOffset = []int{numColsWithoutPid - 1}
 	}
 	handles = make([]kv.Handle, 0, w.batchSize)
 	// PushedLimit would always be nil for CheckIndex or CheckTable, we add this check just for insurance.
@@ -895,6 +902,11 @@ func (e *IndexLookUpExecutor) getHandle(row chunk.Row, handleIdx []int,
 			handle = kv.IntHandle(row.GetInt64(handleIdx[0]))
 		}
 	}
+	if e.index.Global {
+		pidOffset := row.Len() - 1
+		pid := row.GetInt64(pidOffset)
+		handle = kv.NewPartitionHandle(pid, handle)
+	}
 	return
 }
 

executor/executor_test.go

@@ -130,6 +130,7 @@ var _ = SerialSuites(&testSerialSuite1{&baseTestSuite{}})
 var _ = SerialSuites(&testSlowQuery{&baseTestSuite{}})
 var _ = Suite(&partitionTableSuite{&baseTestSuite{}})
 var _ = SerialSuites(&tiflashTestSuite{})
+var _ = SerialSuites(&globalIndexSuite{&baseTestSuite{}})
 var _ = SerialSuites(&testSerialSuite{&baseTestSuite{}})
 
 type testSuite struct{ *baseTestSuite }
@@ -142,6 +143,7 @@ type testSuiteWithData struct {
 }
 type testSlowQuery struct{ *baseTestSuite }
 type partitionTableSuite struct{ *baseTestSuite }
+type globalIndexSuite struct{ *baseTestSuite }
 type testSerialSuite struct{ *baseTestSuite }
 
 type baseTestSuite struct {
@@ -196,6 +198,13 @@ func (s *baseTestSuite) TearDownSuite(c *C) {
 	s.store.Close()
 }
 
+func (s *globalIndexSuite) SetUpSuite(c *C) {
+	s.baseTestSuite.SetUpSuite(c)
+	config.UpdateGlobal(func(conf *config.Config) {
+		conf.EnableGlobalIndex = true
+	})
+}
+
 func (s *testSuiteP1) TestPessimisticSelectForUpdate(c *C) {
 	tk := testkit.NewTestKit(c, s.store)
 	tk.MustExec("use test")

executor/partition_table_test.go

@@ -176,3 +176,27 @@ PRIMARY KEY (pk1,pk2)) partition by hash(pk2) partitions 4;`)
 	tk.MustQuery("select /*+ INL_JOIN(dt, rr) */ * from coverage_dt dt join coverage_rr rr on (dt.pk1 = rr.pk1 and dt.pk2 = rr.pk2);").Sort().Check(testkit.Rows("ios 3 ios 3 2", "linux 5 linux 5 1"))
 	tk.MustQuery("select /*+ INL_MERGE_JOIN(dt, rr) */ * from coverage_dt dt join coverage_rr rr on (dt.pk1 = rr.pk1 and dt.pk2 = rr.pk2);").Sort().Check(testkit.Rows("ios 3 ios 3 2", "linux 5 linux 5 1"))
 }
+
+func (s *globalIndexSuite) TestGlobalIndexScan(c *C) {
+	tk := testkit.NewTestKitWithInit(c, s.store)
+	tk.MustExec("drop table if exists p")
+	tk.MustExec(`create table p (id int, c int) partition by range (c) (
+partition p0 values less than (4),
+partition p1 values less than (7),
+partition p2 values less than (10))`)
+	tk.MustExec("alter table p add unique idx(id)")
+	tk.MustExec("insert into p values (1,3), (3,4), (5,6), (7,9)")
+	tk.MustQuery("select id from p use index (idx)").Check(testkit.Rows("1", "3", "5", "7"))
+}
+
+func (s *globalIndexSuite) TestGlobalIndexDoubleRead(c *C) {
+	tk := testkit.NewTestKitWithInit(c, s.store)
+	tk.MustExec("drop table if exists p")
+	tk.MustExec(`create table p (id int, c int) partition by range (c) (
+partition p0 values less than (4),
+partition p1 values less than (7),
+partition p2 values less than (10))`)
+	tk.MustExec("alter table p add unique idx(id)")
+	tk.MustExec("insert into p values (1,3), (3,4), (5,6), (7,9)")
+	tk.MustQuery("select * from p use index (idx)").Check(testkit.Rows("1 3", "3 4", "5 6", "7 9"))
+}

go.sum

@@ -406,14 +406,11 @@ github.com/ngaut/unistore v0.0.0-20200918091209-68a2db6bb775/go.mod h1:ZR3NH+Hzq
 github.com/nicksnyder/go-i18n v1.10.0/go.mod h1:HrK7VCrbOvQoUAQ7Vpy7i87N7JZZZ7R2xBGjv0j365Q=
 github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
 github.com/olekukonko/tablewriter v0.0.0-20170122224234-a0225b3f23b5/go.mod h1:vsDQFd/mU46D+Z4whnwzcISnGGzXWMclvtLoiIKAKIo=
-github.com/olekukonko/tablewriter v0.0.4 h1:vHD/YYe1Wolo78koG299f7V/VAS08c6IpCLn+Ejf/w8=
 github.com/olekukonko/tablewriter v0.0.4/go.mod h1:zq6QwlOf5SlnkVbMSr5EoBv3636FWnp+qbPhuoO21uA=
-github.com/onsi/ginkgo v1.6.0 h1:Ix8l273rp3QzYgXSR+c8d1fTG7UPgYkOSELPhiY/YGw=
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/ginkgo v1.7.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/ginkgo v1.11.0 h1:JAKSXpt1YjtLA7YpPiqO9ss6sNXEsPfSGdwN0UHqzrw=
 github.com/onsi/ginkgo v1.11.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
-github.com/onsi/gomega v1.4.2 h1:3mYCb7aPxS/RU7TI1y4rkEn1oKmPRjNJLNEXgw7MH2I=
 github.com/onsi/gomega v1.4.2/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
 github.com/onsi/gomega v1.4.3/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
 github.com/onsi/gomega v1.8.1 h1:C5Dqfs/LeauYDX0jJXIe2SWmwCbGzx9yF8C8xy3Lh34=
@@ -425,7 +422,6 @@ github.com/opentracing/opentracing-go v1.1.0 h1:pWlfV3Bxv7k65HYwkikxat0+s3pV4bsq
 github.com/opentracing/opentracing-go v1.1.0/go.mod h1:UkNAQd3GIcIGf0SeVgPpRdFStlNbqXla1AfSYxPUl2o=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
 github.com/pelletier/go-toml v1.3.0/go.mod h1:PN7xzY2wHTK0K9p34ErDQMlFxa51Fk0OUruD3k1mMwo=
-github.com/petermattis/goid v0.0.0-20180202154549-b0b1615b78e5 h1:q2e307iGHPdTGp0hoxKjt1H5pDo6utceo3dQVK3I5XQ=
 github.com/petermattis/goid v0.0.0-20180202154549-b0b1615b78e5/go.mod h1:jvVRKCrJTQWu0XVbaOlby/2lO20uSCHEMzzplHXte1o=
 github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2 h1:JhzVVoYvbOACxoUmOs6V/G4D5nPVUW73rKvXxP4XUJc=
 github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2/go.mod h1:iIss55rKnNBTvrwdmkUpLnDpZoAHvWaiq5+iMmen4AE=
@@ -439,7 +435,6 @@ github.com/pingcap-incubator/tidb-dashboard v0.0.0-20200710045508-523e95bc5ec9/g
 github.com/pingcap-incubator/tidb-dashboard v0.0.0-20200715070228-47f5de8a6992/go.mod h1:9yaAM77sPfa5/f6sdxr3jSkKfIz463KRHyiFHiGjdes=
 github.com/pingcap-incubator/tidb-dashboard v0.0.0-20200807020752-01f0abe88e93/go.mod h1:9yaAM77sPfa5/f6sdxr3jSkKfIz463KRHyiFHiGjdes=
 github.com/pingcap/badger v1.5.1-0.20200604041313-19c397305fcc/go.mod h1:LyrqUOHZrUDf9oGi1yoz1+qw9ckSIhQb5eMa1acOLNQ=
-github.com/pingcap/badger v1.5.1-0.20200714132513-80ba2000f159 h1:cmZSuRbdfOJd3kJjRIClrLbt3nD0xi4oqYR1c/ZrPKg=
 github.com/pingcap/badger v1.5.1-0.20200714132513-80ba2000f159/go.mod h1:LyrqUOHZrUDf9oGi1yoz1+qw9ckSIhQb5eMa1acOLNQ=
 github.com/pingcap/badger v1.5.1-0.20200810065601-8c92a97807f9/go.mod h1:LyrqUOHZrUDf9oGi1yoz1+qw9ckSIhQb5eMa1acOLNQ=
 github.com/pingcap/badger v1.5.1-0.20200908111422-2e78ee155d19 h1:IXpGy7y9HyoShAFmzW2OPF0xCA5EOoSTyZHwsgYk9Ro=
@@ -451,7 +446,6 @@ github.com/pingcap/br v0.0.0-20200617120402-56e151ad8b67/go.mod h1:/3QzpDG7YTPrD
 github.com/pingcap/br v0.0.0-20200727092753-a475692725db/go.mod h1:4iTqZAMbEPmjBggYixqIg2FwIHBQtyImTM/QYlpTBGk=
 github.com/pingcap/br v0.0.0-20200803052654-e6f63fc1807a/go.mod h1:8j7vGUfHCETYbeBfASLTDywC3NFSx90z9nuk0PV9rpo=
 github.com/pingcap/br v0.0.0-20200805121136-181c081ba6ac/go.mod h1:9P24mNzNmXjggYBm4pnb08slSbua8FA6QIyg68GpuhQ=
-github.com/pingcap/br v0.0.0-20200820083933-d9d6207c0aa7 h1:7YWkuK/QY7/nz819lnxb0qDXqLrApDjZHjYPo+tduGA=
 github.com/pingcap/br v0.0.0-20200820083933-d9d6207c0aa7/go.mod h1:5ri8663t7CtJuG0kiOKKoBmwk9HOCX5MoKpmh1fW4CE=
 github.com/pingcap/br v0.0.0-20200923023944-7456456854e4 h1:f1e1xbBAMc6mOrnBtrPRke52Zxv8zVlyr5g0Tz/pySQ=
 github.com/pingcap/br v0.0.0-20200923023944-7456456854e4/go.mod h1:DGsMcZVYt2haeDF/xGerf77c2RpTymgYY5+bMg8uArA=
@@ -460,15 +454,11 @@ github.com/pingcap/check v0.0.0-20191107115940-caf2b9e6ccf4/go.mod h1:PYMCGwN0JH
 github.com/pingcap/check v0.0.0-20191216031241-8a5a85928f12/go.mod h1:PYMCGwN0JHjoqGr3HrZoD+b8Tgx8bKnArhSq8YVzUMc=
 github.com/pingcap/check v0.0.0-20200212061837-5e12011dc712 h1:R8gStypOBmpnHEx1qi//SaqxJVI4inOqljg/Aj5/390=
 github.com/pingcap/check v0.0.0-20200212061837-5e12011dc712/go.mod h1:PYMCGwN0JHjoqGr3HrZoD+b8Tgx8bKnArhSq8YVzUMc=
-github.com/pingcap/errcode v0.0.0-20180921232412-a1a7271709d9 h1:KH4f4Si9XK6/IW50HtoaiLIFHGkapOM6w83za47UYik=
 github.com/pingcap/errcode v0.0.0-20180921232412-a1a7271709d9/go.mod h1:4b2X8xSqxIroj/IZ9MX/VGZhAwc11wB9wRIzHvz6SeM=
 github.com/pingcap/errors v0.11.0/go.mod h1:Oi8TUi2kEtXXLMJk9l1cGmz20kV3TaQ0usTwv5KuLY8=
 github.com/pingcap/errors v0.11.4/go.mod h1:Oi8TUi2kEtXXLMJk9l1cGmz20kV3TaQ0usTwv5KuLY8=
-github.com/pingcap/errors v0.11.5-0.20190809092503-95897b64e011 h1:58naV4XMEqm0hl9LcYo6cZoGBGiLtefMQMF/vo3XLgQ=
 github.com/pingcap/errors v0.11.5-0.20190809092503-95897b64e011/go.mod h1:Oi8TUi2kEtXXLMJk9l1cGmz20kV3TaQ0usTwv5KuLY8=
-github.com/pingcap/errors v0.11.5-0.20200729012136-4e113ddee29e h1:/EGWHNOyEgizEBuAujWsb9vXrPZtt1b7ooDPyjEkjDw=
 github.com/pingcap/errors v0.11.5-0.20200729012136-4e113ddee29e/go.mod h1:g4vx//d6VakjJ0mk7iLBlKA8LFavV/sAVINT/1PFxeQ=
-github.com/pingcap/errors v0.11.5-0.20200902104258-eba4f1d8f6de h1:mW8hC2yXTpflfyTeJgcN4aJQfwcYODde8YgjBgAy6do=
 github.com/pingcap/errors v0.11.5-0.20200902104258-eba4f1d8f6de/go.mod h1:g4vx//d6VakjJ0mk7iLBlKA8LFavV/sAVINT/1PFxeQ=
 github.com/pingcap/errors v0.11.5-0.20200917111840-a15ef68f753d h1:TH18wFO5Nq/zUQuWu9ms2urgZnLP69XJYiI2JZAkUGc=
 github.com/pingcap/errors v0.11.5-0.20200917111840-a15ef68f753d/go.mod h1:g4vx//d6VakjJ0mk7iLBlKA8LFavV/sAVINT/1PFxeQ=
@@ -548,7 +538,6 @@ github.com/pingcap/tidb-tools v4.0.0-rc.1.0.20200421113014-507d2bb3a15e+incompat
 github.com/pingcap/tidb-tools v4.0.0-rc.1.0.20200514040632-f76b3e428e19+incompatible/go.mod h1:XGdcy9+yqlDSEMTpOXnwf3hiTeqrV6MN/u1se9N8yIM=
 github.com/pingcap/tidb-tools v4.0.0+incompatible/go.mod h1:XGdcy9+yqlDSEMTpOXnwf3hiTeqrV6MN/u1se9N8yIM=
 github.com/pingcap/tidb-tools v4.0.1+incompatible/go.mod h1:XGdcy9+yqlDSEMTpOXnwf3hiTeqrV6MN/u1se9N8yIM=
-github.com/pingcap/tidb-tools v4.0.5-0.20200820082341-afeaaaaaa153+incompatible h1:OozchEPztWQsTdLxPSPs6P+Cowbr35J7uy5oRpjbV9E=
 github.com/pingcap/tidb-tools v4.0.5-0.20200820082341-afeaaaaaa153+incompatible/go.mod h1:XGdcy9+yqlDSEMTpOXnwf3hiTeqrV6MN/u1se9N8yIM=
 github.com/pingcap/tidb-tools v4.0.5-0.20200820092506-34ea90c93237+incompatible h1:qPppnsXVh3KswqRZdSAShGLLPd7dB+5w4lXDnpYn0SQ=
 github.com/pingcap/tidb-tools v4.0.5-0.20200820092506-34ea90c93237+incompatible/go.mod h1:XGdcy9+yqlDSEMTpOXnwf3hiTeqrV6MN/u1se9N8yIM=
@@ -597,7 +586,6 @@ github.com/russross/blackfriday v1.5.2/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/sasha-s/go-deadlock v0.2.0/go.mod h1:StQn567HiB1fF2yJ44N9au7wOhrPS3iZqiDbRupzT10=
 github.com/satori/go.uuid v1.2.0/go.mod h1:dA0hQrYB0VpLJoorglMZABFdXlWrHn1NEOzdhQKdks0=
-github.com/sergi/go-diff v1.0.1-0.20180205163309-da645544ed44 h1:tB9NOR21++IjLyVx3/PCPhWMwqGNCMQEH96A6dMZ/gc=
 github.com/sergi/go-diff v1.0.1-0.20180205163309-da645544ed44/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
 github.com/shirou/gopsutil v2.19.10+incompatible h1:lA4Pi29JEVIQIgATSeftHSY0rMGI9CLrl2ZvDLiahto=
 github.com/shirou/gopsutil v2.19.10+incompatible/go.mod h1:5b4v6he4MtMOwMlS0TUMTu2PcXUg8+E1lC7eC3UO/RA=

kv/key.go

@@ -429,3 +429,41 @@ func BuildHandleFromDatumRow(sctx *stmtctx.StatementContext, row []types.Datum,
 	}
 	return handle, nil
 }
+
+// PartitionHandle combines a handle and a PartitionID, used to location a row in partioned table.
+// Now only used in global index.
+// TODO: support PartitionHandle in HandleMap.
+type PartitionHandle struct {
+	Handle
+	PartitionID int64
+}
+
+// NewPartitionHandle creates a PartitionHandle from a normal handle and a pid.
+func NewPartitionHandle(pid int64, h Handle) PartitionHandle {
+	return PartitionHandle{
+		Handle:      h,
+		PartitionID: pid,
+	}
+}
+
+// Equal implements the Handle interface.
+func (ph PartitionHandle) Equal(h Handle) bool {
+	if ph2, ok := h.(PartitionHandle); ok {
+		return ph.PartitionID == ph2.PartitionID && ph.Handle.Equal(ph2.Handle)
+	}
+	return false
+}
+
+// Compare implements the Handle interface.
+func (ph PartitionHandle) Compare(h Handle) int {
+	if ph2, ok := h.(PartitionHandle); ok {
+		if ph.PartitionID < ph2.PartitionID {
+			return -1
+		}
+		if ph.PartitionID > ph2.PartitionID {
+			return 1
+		}
+		return ph.Handle.Compare(ph2.Handle)
+	}
+	panic("PartitonHandle compares to non-parition Handle")
+}

planner/core/find_best_task.go

@@ -1073,8 +1073,6 @@ func (is *PhysicalIndexScan) initSchema(idxExprCols []*expression.Column, isDoub
 		for i := len(is.Index.Columns); i < len(idxExprCols); i++ {
 			indexCols = append(indexCols, idxExprCols[i])
 		}
-		is.SetSchema(expression.NewSchema(indexCols...))
-		return
 	}
 	setHandle := len(indexCols) > len(is.Index.Columns)
 	if !setHandle {
@@ -1086,13 +1084,24 @@ func (is *PhysicalIndexScan) initSchema(idxExprCols []*expression.Column, isDoub
 			}
 		}
 	}
-	// If it's double read case, the first index must return handle. So we should add extra handle column
-	// if there isn't a handle column.
-	if isDoubleRead && !setHandle {
-		if !is.Table.IsCommonHandle {
+
+	if isDoubleRead {
+		// If it's double read case, the first index must return handle. So we should add extra handle column
+		// if there isn't a handle column.
+		if !setHandle {
+			if !is.Table.IsCommonHandle {
+				indexCols = append(indexCols, &expression.Column{
+					RetType:  types.NewFieldType(mysql.TypeLonglong),
+					ID:       model.ExtraHandleID,
+					UniqueID: is.ctx.GetSessionVars().AllocPlanColumnID(),
+				})
+			}
+		}
+		// If index is global, we should add extra column for pid.
+		if is.Index.Global {
 			indexCols = append(indexCols, &expression.Column{
 				RetType:  types.NewFieldType(mysql.TypeLonglong),
-				ID:       model.ExtraHandleID,
+				ID:       model.ExtraPidColID,
 				UniqueID: is.ctx.GetSessionVars().AllocPlanColumnID(),
 			})
 		}

planner/core/plan_to_pb.go

@@ -202,6 +202,8 @@ func (p *PhysicalIndexScan) ToPB(ctx sessionctx.Context, _ kv.StoreType) (*tipb.
 	for _, col := range p.schema.Columns {
 		if col.ID == model.ExtraHandleID {
 			columns = append(columns, model.NewExtraHandleColInfo())
+		} else if col.ID == model.ExtraPidColID {
+			columns = append(columns, model.NewExtraPartitionIDColInfo())
 		} else {
 			columns = append(columns, findColumnInfoByID(tableColumns, col.ID))
 		}

store/mockstore/unistore/cophandler/closure_exec.go

@@ -168,8 +168,11 @@ func (e *closureExecutor) initIdxScanCtx(idxScan *tipb.IndexScan) {
 	e.idxScanCtx.pkStatus = pkColNotExists
 
 	e.idxScanCtx.primaryColumnIds = idxScan.PrimaryColumnIds
-
 	lastColumn := e.columnInfos[len(e.columnInfos)-1]
+	if lastColumn.GetColumnId() == model.ExtraPidColID {
+		lastColumn = e.columnInfos[len(e.columnInfos)-2]
+		e.idxScanCtx.columnLen--
+	}
 
 	if len(e.idxScanCtx.primaryColumnIds) == 0 {
 		if lastColumn.GetPkHandle() {