planner,executor: fix cached table query with filter condition

executor/builder.go

@@ -152,7 +152,6 @@ func (b *MockExecutorBuilder) Build(p plannercore.Plan) Executor {
 }
 
 func (b *executorBuilder) build(p plannercore.Plan) Executor {
-	var e Executor
 	switch v := p.(type) {
 	case nil:
 		return nil
@@ -267,13 +266,13 @@ func (b *executorBuilder) build(p plannercore.Plan) Executor {
 	case *plannercore.Analyze:
 		return b.buildAnalyze(v)
 	case *plannercore.PhysicalTableReader:
-		e = b.buildTableReader(v)
+		return b.buildTableReader(v)
 	case *plannercore.PhysicalTableSample:
 		return b.buildTableSample(v)
 	case *plannercore.PhysicalIndexReader:
-		e = b.buildIndexReader(v)
+		return b.buildIndexReader(v)
 	case *plannercore.PhysicalIndexLookUpReader:
-		e = b.buildIndexLookUpReader(v)
+		return b.buildIndexLookUpReader(v)
 	case *plannercore.PhysicalWindow:
 		return b.buildWindow(v)
 	case *plannercore.PhysicalShuffle:
@@ -304,57 +303,6 @@ func (b *executorBuilder) build(p plannercore.Plan) Executor {
 		b.err = ErrUnknownPlan.GenWithStack("Unknown Plan %T", p)
 		return nil
 	}
-
-	if tblExec, ok := e.(dataSourceExecutor); ok {
-		tbl := tblExec.Table()
-		tableInfo := tbl.Meta()
-		// When reading from a cached table, check whether it satisfies the conditions of read cache.
-		if tableInfo.TableCacheStatusType == model.TableCacheStatusEnable {
-			physicalPlan := p.(plannercore.PhysicalPlan)
-			return b.buildCachedTableExecutor(tbl, physicalPlan, e)
-		}
-	}
-
-	return e
-}
-
-// buildCachedTableExecutor adds an UnionScan to the original Executor to make the reader read from table cache.
-func (b *executorBuilder) buildCachedTableExecutor(tbl table.Table, p plannercore.PhysicalPlan, e Executor) Executor {
-	if b.ctx.GetSessionVars().SnapshotTS != 0 || b.ctx.GetSessionVars().StmtCtx.IsStaleness {
-		return e
-	}
-
-	cachedTable := tbl.(table.CachedTable)
-	startTS, err := b.getSnapshotTS()
-	if err != nil {
-		b.err = errors.Trace(err)
-		return nil
-	}
-
-	leaseDuration := time.Duration(variable.TableCacheLease.Load()) * time.Second
-	sessionVars := b.ctx.GetSessionVars()
-	// Use the TS of the transaction to determine whether the cache can be used.
-	cacheData := cachedTable.TryReadFromCache(startTS, leaseDuration)
-	if cacheData != nil {
-		sessionVars.StmtCtx.ReadFromTableCache = true
-		switch raw := e.(type) {
-		case *TableReaderExecutor:
-			raw.dummy = true
-		case *IndexReaderExecutor:
-			raw.dummy = true
-		case *IndexLookUpExecutor:
-			raw.dummy = true
-		}
-		us := plannercore.PhysicalUnionScan{CacheTable: cacheData}.Init(b.ctx, nil, -1)
-		us.SetChildren(p)
-		e = b.buildUnionScanFromReader(e, us)
-	} else {
-		if !b.inUpdateStmt && !b.inDeleteStmt && !b.inInsertStmt && !sessionVars.StmtCtx.InExplainStmt {
-			store := b.ctx.GetStore()
-			cachedTable.UpdateLockForRead(context.Background(), store, startTS, leaseDuration)
-		}
-	}
-	return e
 }
 
 func (b *executorBuilder) buildCancelDDLJobs(v *plannercore.CancelDDLJobs) Executor {
@@ -1118,7 +1066,6 @@ func (b *executorBuilder) buildUnionScanFromReader(reader Executor, v *plannerco
 		return x
 	}
 	us := &UnionScanExec{baseExecutor: newBaseExecutor(b.ctx, v.Schema(), v.ID(), reader)}
-	us.cacheTable = v.CacheTable
 	// Get the handle column index of the below Plan.
 	us.belowHandleCols = v.HandleCols
 	us.mutableRow = chunk.MutRowFromTypes(retTypes(us))
@@ -1134,13 +1081,21 @@ func (b *executorBuilder) buildUnionScanFromReader(reader Executor, v *plannerco
 		us.collators = append(us.collators, collate.GetCollator(tp.Collate))
 	}
 
+	startTS, err := b.getSnapshotTS()
+	sessionVars := b.ctx.GetSessionVars()
+	if err != nil {
+		b.err = err
+		return nil
+	}
+
 	switch x := reader.(type) {
 	case *TableReaderExecutor:
 		us.desc = x.desc
 		us.conditions, us.conditionsWithVirCol = plannercore.SplitSelCondsWithVirtualColumn(v.Conditions)
 		us.columns = x.columns
 		us.table = x.table
 		us.virtualColumnIndex = x.virtualColumnIndex
+		us.handleCachedTable(b, x, sessionVars, startTS)
 	case *IndexReaderExecutor:
 		us.desc = x.desc
 		for _, ic := range x.index.Columns {
@@ -1154,6 +1109,7 @@ func (b *executorBuilder) buildUnionScanFromReader(reader Executor, v *plannerco
 		us.conditions, us.conditionsWithVirCol = plannercore.SplitSelCondsWithVirtualColumn(v.Conditions)
 		us.columns = x.columns
 		us.table = x.table
+		us.handleCachedTable(b, x, sessionVars, startTS)
 	case *IndexLookUpExecutor:
 		us.desc = x.desc
 		for _, ic := range x.index.Columns {
@@ -1168,6 +1124,7 @@ func (b *executorBuilder) buildUnionScanFromReader(reader Executor, v *plannerco
 		us.columns = x.columns
 		us.table = x.table
 		us.virtualColumnIndex = buildVirtualColumnIndex(us.Schema(), us.columns)
+		us.handleCachedTable(b, x, sessionVars, startTS)
 	case *IndexMergeReaderExecutor:
 		// IndexMergeReader doesn't care order for now. So we will not set desc and useIndex.
 		us.conditions, us.conditionsWithVirCol = plannercore.SplitSelCondsWithVirtualColumn(v.Conditions)
@@ -1181,6 +1138,31 @@ func (b *executorBuilder) buildUnionScanFromReader(reader Executor, v *plannerco
 	return us
 }
 
+type bypassDataSourceExecutor interface {
+	dataSourceExecutor
+	setDummy()
+}
+
+func (us *UnionScanExec) handleCachedTable(b *executorBuilder, x bypassDataSourceExecutor, vars *variable.SessionVars, startTS uint64) {
+	tbl := x.Table()
+	if tbl.Meta().TableCacheStatusType == model.TableCacheStatusEnable {
+		cachedTable := tbl.(table.CachedTable)
+		// Determine whether the cache can be used.
+		leaseDuration := time.Duration(variable.TableCacheLease.Load()) * time.Second
+		cacheData := cachedTable.TryReadFromCache(startTS, leaseDuration)
+		if cacheData != nil {
+			vars.StmtCtx.ReadFromTableCache = true
+			x.setDummy()
+			us.cacheTable = cacheData
+		} else {
+			if !b.inUpdateStmt && !b.inDeleteStmt && !b.inInsertStmt && !vars.StmtCtx.InExplainStmt {
+				store := b.ctx.GetStore()
+				cachedTable.UpdateLockForRead(context.Background(), store, startTS, leaseDuration)
+			}
+		}
+	}
+}
+
 // buildMergeJoin builds MergeJoinExec executor.
 func (b *executorBuilder) buildMergeJoin(v *plannercore.PhysicalMergeJoin) Executor {
 	leftExec := b.build(v.Children()[0])

executor/distsql.go

@@ -207,6 +207,10 @@ func (e *IndexReaderExecutor) Table() table.Table {
 	return e.table
 }
 
+func (e *IndexReaderExecutor) setDummy() {
+	e.dummy = true
+}
+
 // Close clears all resources hold by current object.
 func (e *IndexReaderExecutor) Close() (err error) {
 	if e.dummy {
@@ -412,6 +416,10 @@ func (e *IndexLookUpExecutor) Table() table.Table {
 	return e.table
 }
 
+func (e *IndexLookUpExecutor) setDummy() {
+	e.dummy = true
+}
+
 // Open implements the Executor Open interface.
 func (e *IndexLookUpExecutor) Open(ctx context.Context) error {
 	var err error

executor/table_reader.go

@@ -118,6 +118,10 @@ func (e *TableReaderExecutor) Table() table.Table {
 	return e.table
 }
 
+func (e *TableReaderExecutor) setDummy() {
+	e.dummy = true
+}
+
 // Open initializes necessary variables for using this executor.
 func (e *TableReaderExecutor) Open(ctx context.Context) error {
 	if span := opentracing.SpanFromContext(ctx); span != nil && span.Tracer() != nil {

executor/union_scan_test.go

@@ -17,6 +17,7 @@ package executor_test
 import (
 	"fmt"
 	"testing"
+	"time"
 
 	"github.com/pingcap/tidb/executor"
 	"github.com/pingcap/tidb/tablecodec"
@@ -457,6 +458,68 @@ func TestIssue28073(t *testing.T) {
 	require.False(t, exist)
 }
 
+func TestIssue32422(t *testing.T) {
+	store, clean := testkit.CreateMockStore(t)
+	defer clean()
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t")
+
+	tk.MustExec("create table t (id int, c int, index(id));")
+	tk.MustExec("insert into t values (3,3), (4,4), (5,5);")
+	tk.MustExec("alter table t cache;")
+
+	var cacheUsed bool
+	for i := 0; i < 20; i++ {
+		tk.MustQuery("select id+1, c from t where c = 4;").Check(testkit.Rows("5 4"))
+		if tk.Session().GetSessionVars().StmtCtx.ReadFromTableCache {
+			cacheUsed = true
+			break
+		}
+		time.Sleep(50 * time.Millisecond)
+	}
+	require.True(t, cacheUsed)
+
+	tk.MustQuery("select id+1, c from t where c = 4;").Check(testkit.Rows("5 4"))
+
+	// Some extra tests.
+	// Since cached table use UnionScanExec utilities, check what happens when they work together.
+	// In these cases, the cache data serve as the snapshot, tikv is skipped, and txn membuffer works the same way.
+	tk.MustExec("begin")
+	tk.MustQuery("select id+1, c from t where c = 4;").Check(testkit.Rows("5 4"))
+	tk.MustExec("insert into t values (6, 6)")
+	// Check for the new added data.
+	tk.HasPlan("select id+1, c from t where c = 6;", "UnionScan")
+	tk.MustQuery("select id+1, c from t where c = 6;").Check(testkit.Rows("7 6"))
+	require.True(t, tk.Session().GetSessionVars().StmtCtx.ReadFromTableCache)
+	// Check for the old data.
+	tk.MustQuery("select id+1, c from t where c = 4;").Check(testkit.Rows("5 4"))
+	require.True(t, tk.Session().GetSessionVars().StmtCtx.ReadFromTableCache)
+
+	// Point get
+	tk.HasPlan("select id+1, c from t where id = 6", "PointGet")
+	tk.MustQuery("select id+1, c from t where id = 6").Check(testkit.Rows("7 6"))
+	require.True(t, tk.Session().GetSessionVars().StmtCtx.ReadFromTableCache)
+	tk.MustQuery("select id+1, c from t where id = 4").Check(testkit.Rows("5 4"))
+	require.True(t, tk.Session().GetSessionVars().StmtCtx.ReadFromTableCache)
+
+	// Index Lookup
+	tk.HasPlan("select id+1, c from t where id = 6", "IndexLookUp")
+	tk.MustQuery("select id+1, c from t use index(id) where id = 6").Check(testkit.Rows("7 6"))
+	require.True(t, tk.Session().GetSessionVars().StmtCtx.ReadFromTableCache)
+	tk.MustQuery("select id+1, c from t use index(id) where id = 4").Check(testkit.Rows("5 4"))
+	require.True(t, tk.Session().GetSessionVars().StmtCtx.ReadFromTableCache)
+
+	// Index Reader
+	tk.HasPlan("select id from t where id = 6", "IndexReader")
+	tk.MustQuery("select id from t use index(id) where id = 6").Check(testkit.Rows("6"))
+	require.True(t, tk.Session().GetSessionVars().StmtCtx.ReadFromTableCache)
+	tk.MustQuery("select id from t use index(id) where id = 4").Check(testkit.Rows("4"))
+	require.True(t, tk.Session().GetSessionVars().StmtCtx.ReadFromTableCache)
+
+	tk.MustExec("rollback")
+}
+
 func BenchmarkUnionScanRead(b *testing.B) {
 	store, clean := testkit.CreateMockStore(b)
 	defer clean()

planner/core/exhaust_physical_plans.go

@@ -52,7 +52,6 @@ func (p *LogicalUnionScan) exhaustPhysicalPlans(prop *property.PhysicalProperty)
 	us := PhysicalUnionScan{
 		Conditions: p.conditions,
 		HandleCols: p.handleCols,
-		CacheTable: p.cacheTable,
 	}.Init(p.ctx, p.stats, p.blockOffset, childProp)
 	return []PhysicalPlan{us}, true, nil
 }

planner/core/integration_test.go

@@ -6098,9 +6098,10 @@ func TestAggPushToCopForCachedTable(t *testing.T) {
 
 	tk.MustQuery("explain format = 'brief' select /*+AGG_TO_COP()*/ count(*) from t32157 ignore index(primary) where process_code = 'GDEP0071'").Check(testkit.Rows(
 		"StreamAgg 1.00 root  funcs:count(1)->Column#8]\n" +
-			"[└─TableReader 10.00 root  data:Selection]\n" +
-			"[  └─Selection 10.00 cop[tikv]  eq(test.t32157.process_code, \"GDEP0071\")]\n" +
-			"[    └─TableFullScan 10000.00 cop[tikv] table:t32157 keep order:false, stats:pseudo"))
+			"[└─UnionScan 10.00 root  eq(test.t32157.process_code, \"GDEP0071\")]\n" +
+			"[  └─TableReader 10.00 root  data:Selection]\n" +
+			"[    └─Selection 10.00 cop[tikv]  eq(test.t32157.process_code, \"GDEP0071\")]\n" +
+			"[      └─TableFullScan 10000.00 cop[tikv] table:t32157 keep order:false, stats:pseudo"))
 
 	var readFromCacheNoPanic bool
 	for i := 0; i < 10; i++ {

planner/core/logical_plan_builder.go

@@ -4233,7 +4233,7 @@ func (b *PlanBuilder) buildDataSource(ctx context.Context, tn *ast.TableName, as
 
 	var result LogicalPlan = ds
 	dirty := tableHasDirtyContent(b.ctx, tableInfo)
-	if dirty || tableInfo.TempTableType == model.TempTableLocal {
+	if dirty || tableInfo.TempTableType == model.TempTableLocal || tableInfo.TableCacheStatusType == model.TableCacheStatusEnable {
 		us := LogicalUnionScan{handleCols: handleCols}.Init(b.ctx, b.getSelectOffset())
 		us.SetChildren(ds)
 		if tableInfo.Partition != nil && b.optFlag&flagPartitionProcessor == 0 {

planner/core/logical_plans.go

@@ -20,7 +20,6 @@ import (
 	"github.com/pingcap/tidb/expression"
 	"github.com/pingcap/tidb/expression/aggregation"
 	"github.com/pingcap/tidb/infoschema"
-	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/parser/ast"
 	"github.com/pingcap/tidb/parser/auth"
 	"github.com/pingcap/tidb/parser/model"
@@ -533,9 +532,6 @@ type LogicalUnionScan struct {
 	conditions []expression.Expression
 
 	handleCols HandleCols
-
-	// cacheTable not nil means it's reading from cached table.
-	cacheTable kv.MemBuffer
 }
 
 // DataSource represents a tableScan without condition push down.

planner/core/physical_plans.go

@@ -1185,8 +1185,6 @@ type PhysicalUnionScan struct {
 	Conditions []expression.Expression
 
 	HandleCols HandleCols
-
-	CacheTable kv.MemBuffer
 }
 
 // ExtractCorrelatedCols implements PhysicalPlan interface.