stats: incremental analyze for index with feedback updates (#10355)

executor/analyze.go

@@ -1075,13 +1075,13 @@ func (e *AnalyzeTestFastExec) TestFastSample() error {
 
 type analyzeIndexIncrementalExec struct {
 	AnalyzeIndexExec
-	index *statistics.Index
+	oldHist *statistics.Histogram
+	oldCMS  *statistics.CMSketch
 }
 
 func analyzeIndexIncremental(idxExec *analyzeIndexIncrementalExec) analyzeResult {
-	idx := idxExec.index
-	highBound := idx.Histogram.GetUpper(idx.Len() - 1)
-	values, err := codec.Decode(highBound.GetBytes(), len(idxExec.idxInfo.Columns))
+	startPos := idxExec.oldHist.GetUpper(idxExec.oldHist.Len() - 1)
+	values, err := codec.DecodeRange(startPos.GetBytes(), len(idxExec.idxInfo.Columns))
 	if err != nil {
 		return analyzeResult{Err: err, job: idxExec.job}
 	}
@@ -1090,16 +1090,12 @@ func analyzeIndexIncremental(idxExec *analyzeIndexIncrementalExec) analyzeResult
 	if err != nil {
 		return analyzeResult{Err: err, job: idxExec.job}
 	}
-	oldHist, oldCMS, err := idx.RemoveUpperBound(idxExec.ctx.GetSessionVars().StmtCtx, values)
+	hist, err = statistics.MergeHistograms(idxExec.ctx.GetSessionVars().StmtCtx, idxExec.oldHist, hist, int(idxExec.maxNumBuckets))
 	if err != nil {
 		return analyzeResult{Err: err, job: idxExec.job}
 	}
-	hist, err = statistics.MergeHistograms(idxExec.ctx.GetSessionVars().StmtCtx, oldHist, hist, int(idxExec.maxNumBuckets))
-	if err != nil {
-		return analyzeResult{Err: err, job: idxExec.job}
-	}
-	if oldCMS != nil && cms != nil {
-		err = cms.MergeCMSketch(oldCMS)
+	if idxExec.oldCMS != nil && cms != nil {
+		err = cms.MergeCMSketch4IncrementalAnalyze(idxExec.oldCMS)
 		if err != nil {
 			return analyzeResult{Err: err, job: idxExec.job}
 		}
@@ -1120,26 +1116,24 @@ func analyzeIndexIncremental(idxExec *analyzeIndexIncrementalExec) analyzeResult
 
 type analyzePKIncrementalExec struct {
 	AnalyzeColumnsExec
-	pkStats *statistics.Column
+	oldHist *statistics.Histogram
 }
 
 func analyzePKIncremental(colExec *analyzePKIncrementalExec) analyzeResult {
-	pkStats := colExec.pkStats
-	high := pkStats.GetUpper(pkStats.Len() - 1)
 	var maxVal types.Datum
 	if mysql.HasUnsignedFlag(colExec.pkInfo.Flag) {
 		maxVal = types.NewUintDatum(math.MaxUint64)
 	} else {
 		maxVal = types.NewIntDatum(math.MaxInt64)
 	}
-	ran := ranger.Range{LowVal: []types.Datum{*high}, LowExclude: true, HighVal: []types.Datum{maxVal}}
+	startPos := *colExec.oldHist.GetUpper(colExec.oldHist.Len() - 1)
+	ran := ranger.Range{LowVal: []types.Datum{startPos}, LowExclude: true, HighVal: []types.Datum{maxVal}}
 	hists, _, err := colExec.buildStats([]*ranger.Range{&ran})
 	if err != nil {
 		return analyzeResult{Err: err, job: colExec.job}
 	}
 	hist := hists[0]
-	oldHist := pkStats.Histogram.Copy()
-	hist, err = statistics.MergeHistograms(colExec.ctx.GetSessionVars().StmtCtx, oldHist, hist, int(colExec.maxNumBuckets))
+	hist, err = statistics.MergeHistograms(colExec.ctx.GetSessionVars().StmtCtx, colExec.oldHist, hist, int(colExec.maxNumBuckets))
 	if err != nil {
 		return analyzeResult{Err: err, job: colExec.job}
 	}

executor/analyze_test.go

@@ -24,9 +24,13 @@ import (
 	"github.com/pingcap/tidb/executor"
 	"github.com/pingcap/tidb/session"
 	"github.com/pingcap/tidb/sessionctx"
+	"github.com/pingcap/tidb/statistics"
+	"github.com/pingcap/tidb/statistics/handle"
 	"github.com/pingcap/tidb/store/mockstore"
 	"github.com/pingcap/tidb/store/mockstore/mocktikv"
 	"github.com/pingcap/tidb/table"
+	"github.com/pingcap/tidb/types"
+	"github.com/pingcap/tidb/util/codec"
 	"github.com/pingcap/tidb/util/testkit"
 )
 
@@ -303,4 +307,36 @@ func (s *testSuite1) TestAnalyzeIncremental(c *C) {
 	tk.MustExec("analyze incremental table t index")
 	// Result should not change.
 	tk.MustQuery("show stats_buckets").Check(testkit.Rows("test t  a 0 0 1 1 1 1", "test t  a 0 1 2 1 2 2", "test t  idx 1 0 1 1 1 1", "test t  idx 1 1 2 1 2 2"))
+
+	// Test analyze incremental with feedback.
+	tk.MustExec("insert into t values (3,3)")
+	oriProbability := statistics.FeedbackProbability.Load()
+	defer func() {
+		statistics.FeedbackProbability.Store(oriProbability)
+	}()
+	statistics.FeedbackProbability.Store(1)
+	is := s.dom.InfoSchema()
+	table, err := is.TableByName(model.NewCIStr("test"), model.NewCIStr("t"))
+	c.Assert(err, IsNil)
+	tblInfo := table.Meta()
+	tk.MustQuery("select * from t use index(idx) where b = 3")
+	tk.MustQuery("select * from t where a > 1")
+	h := s.dom.StatsHandle()
+	c.Assert(h.DumpStatsDeltaToKV(handle.DumpAll), IsNil)
+	c.Assert(h.DumpStatsFeedbackToKV(), IsNil)
+	c.Assert(h.HandleUpdateStats(is), IsNil)
+	c.Assert(h.Update(is), IsNil)
+	tk.MustQuery("show stats_buckets").Check(testkit.Rows("test t  a 0 0 1 1 1 1", "test t  a 0 1 3 0 2 2147483647", "test t  idx 1 0 1 1 1 1", "test t  idx 1 1 2 1 2 2"))
+	tblStats := h.GetTableStats(tblInfo)
+	val, err := codec.EncodeKey(tk.Se.GetSessionVars().StmtCtx, nil, types.NewIntDatum(3))
+	c.Assert(err, IsNil)
+	c.Assert(tblStats.Indices[tblInfo.Indices[0].ID].CMSketch.QueryBytes(val), Equals, uint64(1))
+	c.Assert(statistics.IsAnalyzed(tblStats.Indices[tblInfo.Indices[0].ID].Flag), IsFalse)
+	c.Assert(statistics.IsAnalyzed(tblStats.Columns[tblInfo.Columns[0].ID].Flag), IsFalse)
+
+	tk.MustExec("analyze incremental table t index")
+	tk.MustQuery("show stats_buckets").Check(testkit.Rows("test t  a 0 0 1 1 1 1", "test t  a 0 1 2 1 2 2", "test t  a 0 2 3 1 3 3",
+		"test t  idx 1 0 1 1 1 1", "test t  idx 1 1 2 1 2 2", "test t  idx 1 2 3 1 3 3"))
+	tblStats = h.GetTableStats(tblInfo)
+	c.Assert(tblStats.Indices[tblInfo.Indices[0].ID].CMSketch.QueryBytes(val), Equals, uint64(1))
 }

executor/builder.go

@@ -1398,18 +1398,28 @@ func (b *executorBuilder) buildAnalyzeIndexIncremental(task plannercore.AnalyzeI
 		return analyzeTask
 	}
 	idx, ok := statsTbl.Indices[task.IndexInfo.ID]
-	// TODO: If the index contains feedback, we may use other strategy.
-	if !ok || idx.Len() == 0 || idx.ContainsFeedback() {
+	if !ok || idx.Len() == 0 || idx.LastAnalyzePos.IsNull() {
 		return analyzeTask
 	}
-	exec := analyzeTask.idxExec
-	if idx.CMSketch != nil {
-		width, depth := idx.CMSketch.GetWidthAndDepth()
-		exec.analyzePB.IdxReq.CmsketchWidth = &width
-		exec.analyzePB.IdxReq.CmsketchDepth = &depth
+	var oldHist *statistics.Histogram
+	if statistics.IsAnalyzed(idx.Flag) {
+		exec := analyzeTask.idxExec
+		if idx.CMSketch != nil {
+			width, depth := idx.CMSketch.GetWidthAndDepth()
+			exec.analyzePB.IdxReq.CmsketchWidth = &width
+			exec.analyzePB.IdxReq.CmsketchDepth = &depth
+		}
+		oldHist = idx.Histogram.Copy()
+	} else {
+		_, bktID := idx.LessRowCountWithBktIdx(idx.LastAnalyzePos)
+		if bktID == 0 {
+			return analyzeTask
+		}
+		oldHist = idx.TruncateHistogram(bktID)
 	}
+	oldHist = oldHist.RemoveUpperBound()
 	analyzeTask.taskType = idxIncrementalTask
-	analyzeTask.idxIncrementalExec = &analyzeIndexIncrementalExec{AnalyzeIndexExec: *analyzeTask.idxExec, index: idx}
+	analyzeTask.idxIncrementalExec = &analyzeIndexIncrementalExec{AnalyzeIndexExec: *analyzeTask.idxExec, oldHist: oldHist, oldCMS: idx.CMSketch}
 	analyzeTask.job = &statistics.AnalyzeJob{DBName: task.DBName, TableName: task.TableName, PartitionName: task.PartitionName, JobInfo: "analyze incremental index " + task.IndexInfo.Name.O}
 	return analyzeTask
 }
@@ -1458,13 +1468,28 @@ func (b *executorBuilder) buildAnalyzePKIncremental(task plannercore.AnalyzeColu
 		return analyzeTask
 	}
 	col, ok := statsTbl.Columns[task.PKInfo.ID]
-	// TODO: If the primary key contains feedback, we may use other strategy.
-	if !ok || col.Len() == 0 || col.ContainsFeedback() {
+	if !ok || col.Len() == 0 || col.LastAnalyzePos.IsNull() {
 		return analyzeTask
 	}
+	var oldHist *statistics.Histogram
+	if statistics.IsAnalyzed(col.Flag) {
+		oldHist = col.Histogram.Copy()
+	} else {
+		d, err := col.LastAnalyzePos.ConvertTo(b.ctx.GetSessionVars().StmtCtx, col.Tp)
+		if err != nil {
+			b.err = err
+			return nil
+		}
+		_, bktID := col.LessRowCountWithBktIdx(d)
+		if bktID == 0 {
+			return analyzeTask
+		}
+		oldHist = col.TruncateHistogram(bktID)
+		oldHist.NDV = int64(oldHist.TotalRowCount())
+	}
 	exec := analyzeTask.colExec
 	analyzeTask.taskType = pkIncrementalTask
-	analyzeTask.colIncrementalExec = &analyzePKIncrementalExec{AnalyzeColumnsExec: *exec, pkStats: col}
+	analyzeTask.colIncrementalExec = &analyzePKIncrementalExec{AnalyzeColumnsExec: *exec, oldHist: oldHist}
 	analyzeTask.job = &statistics.AnalyzeJob{DBName: task.DBName, TableName: task.TableName, PartitionName: task.PartitionName, JobInfo: "analyze incremental primary key"}
 	return analyzeTask
 }

executor/executor_test.go

@@ -2514,6 +2514,7 @@ func (s *testSuite1) SetUpSuite(c *C) {
 	c.Assert(err, IsNil)
 	s.dom, err = session.BootstrapSession(s.store)
 	c.Assert(err, IsNil)
+	s.dom.SetStatsUpdating(true)
 }
 
 func (s *testSuite1) TearDownSuite(c *C) {

session/bootstrap.go

@@ -171,6 +171,7 @@ const (
 		stats_ver bigint(64) NOT NULL DEFAULT 0,
 		flag bigint(64) NOT NULL DEFAULT 0,
 		correlation double NOT NULL DEFAULT 0,
+		last_analyze_pos blob DEFAULT NULL,
 		unique index tbl(table_id, is_index, hist_id)
 	);`
 
@@ -328,6 +329,7 @@ const (
 	version28 = 28
 	version29 = 29
 	version30 = 30
+	version31 = 31
 )
 
 func checkBootstrapped(s Session) (bool, error) {
@@ -507,6 +509,10 @@ func upgrade(s Session) {
 		upgradeToVer30(s)
 	}
 
+	if ver < version31 {
+		upgradeToVer31(s)
+	}
+
 	updateBootstrapVer(s)
 	_, err = s.Execute(context.Background(), "COMMIT")
 
@@ -799,6 +805,10 @@ func upgradeToVer30(s Session) {
 	mustExecute(s, CreateStatsTopNTable)
 }
 
+func upgradeToVer31(s Session) {
+	doReentrantDDL(s, "ALTER TABLE mysql.stats_histograms ADD COLUMN `last_analyze_pos` blob default null", infoschema.ErrColumnExists)
+}
+
 // updateBootstrapVer updates bootstrap version variable in mysql.TiDB table.
 func updateBootstrapVer(s Session) {
 	// Update bootstrap version.

session/session.go

@@ -1559,7 +1559,7 @@ func createSessionWithDomain(store kv.Storage, dom *domain.Domain) (*session, er
 
 const (
 	notBootstrapped         = 0
-	currentBootstrapVersion = 30
+	currentBootstrapVersion = 31
 )
 
 func getStoreBootstrapVersion(store kv.Storage) int64 {

statistics/cmsketch.go

@@ -298,6 +298,31 @@ func (c *CMSketch) MergeCMSketch(rc *CMSketch) error {
 	return nil
 }
 
+// MergeCMSketch4IncrementalAnalyze merges two CM Sketch for incremental analyze. Since there is no value
+// that appears partially in `c` and `rc` for incremental analyze, it uses `max` to merge them.
+// Here is a simple proof: when we query from the CM sketch, we use the `min` to get the answer:
+//   (1): For values that only appears in `c, using `max` to merge them affects the `min` query result less than using `sum`;
+//   (2): For values that only appears in `rc`, it is the same as condition (1);
+//   (3): For values that appears both in `c` and `rc`, if they do not appear partially in `c` and `rc`, for example,
+//        if `v` appears 5 times in the table, it can appears 5 times in `c` and 3 times in `rc`, then `max` also gives the correct answer.
+// So in fact, if we can know the number of appearances of each value in the first place, it is better to use `max` to construct the CM sketch rather than `sum`.
+func (c *CMSketch) MergeCMSketch4IncrementalAnalyze(rc *CMSketch) error {
+	if c.depth != rc.depth || c.width != rc.width {
+		return errors.New("Dimensions of Count-Min Sketch should be the same")
+	}
+	if c.topN != nil || rc.topN != nil {
+		return errors.New("CMSketch with Top-N does not support merge")
+	}
+	for i := range c.table {
+		c.count = 0
+		for j := range c.table[i] {
+			c.table[i][j] = mathutil.MaxUint32(c.table[i][j], rc.table[i][j])
+			c.count += uint64(c.table[i][j])
+		}
+	}
+	return nil
+}
+
 // CMSketchToProto converts CMSketch to its protobuf representation.
 func CMSketchToProto(c *CMSketch) *tipb.CMSketch {
 	protoSketch := &tipb.CMSketch{Rows: make([]*tipb.CMSketchRow, c.depth)}

statistics/handle/bootstrap.go

@@ -109,7 +109,7 @@ func (h *Handle) initStatsHistograms4Chunk(is infoschema.InfoSchema, tables Stat
 				terror.Log(errors.Trace(err))
 			}
 			hist := statistics.NewHistogram(id, ndv, nullCount, version, types.NewFieldType(mysql.TypeBlob), chunk.InitialCapacity, 0)
-			table.Indices[hist.ID] = &statistics.Index{Histogram: *hist, CMSketch: cms, Info: idxInfo, StatsVer: row.GetInt64(8)}
+			table.Indices[hist.ID] = &statistics.Index{Histogram: *hist, CMSketch: cms, Info: idxInfo, StatsVer: row.GetInt64(8), Flag: row.GetInt64(10), LastAnalyzePos: row.GetDatum(11, types.NewFieldType(mysql.TypeBlob))}
 		} else {
 			var colInfo *model.ColumnInfo
 			for _, col := range tbl.Meta().Columns {
@@ -124,11 +124,13 @@ func (h *Handle) initStatsHistograms4Chunk(is infoschema.InfoSchema, tables Stat
 			hist := statistics.NewHistogram(id, ndv, nullCount, version, &colInfo.FieldType, 0, totColSize)
 			hist.Correlation = row.GetFloat64(9)
 			table.Columns[hist.ID] = &statistics.Column{
-				Histogram:  *hist,
-				PhysicalID: table.PhysicalID,
-				Info:       colInfo,
-				Count:      nullCount,
-				IsHandle:   tbl.Meta().PKIsHandle && mysql.HasPriKeyFlag(colInfo.Flag),
+				Histogram:      *hist,
+				PhysicalID:     table.PhysicalID,
+				Info:           colInfo,
+				Count:          nullCount,
+				IsHandle:       tbl.Meta().PKIsHandle && mysql.HasPriKeyFlag(colInfo.Flag),
+				Flag:           row.GetInt64(10),
+				LastAnalyzePos: row.GetDatum(11, types.NewFieldType(mysql.TypeBlob)),
 			}
 		}
 	}
@@ -137,7 +139,7 @@ func (h *Handle) initStatsHistograms4Chunk(is infoschema.InfoSchema, tables Stat
 func (h *Handle) initStatsHistograms(is infoschema.InfoSchema, tables StatsCache) error {
 	h.mu.Lock()
 	defer h.mu.Unlock()
-	sql := "select HIGH_PRIORITY table_id, is_index, hist_id, distinct_count, version, null_count, cm_sketch, tot_col_size, stats_ver, correlation from mysql.stats_histograms"
+	sql := "select HIGH_PRIORITY table_id, is_index, hist_id, distinct_count, version, null_count, cm_sketch, tot_col_size, stats_ver, correlation, flag, last_analyze_pos from mysql.stats_histograms"
 	rc, err := h.mu.ctx.(sqlexec.SQLExecutor).Execute(context.TODO(), sql)
 	if len(rc) > 0 {
 		defer terror.Call(rc[0].Close)