statistics: remove unused LastAnalyzePos field (#58859)

ref #55043

pkg/statistics/column.go

@@ -26,11 +26,10 @@ import (
 
 // Column represents a column histogram.
 type Column struct {
-	LastAnalyzePos types.Datum
-	CMSketch       *CMSketch
-	TopN           *TopN
-	FMSketch       *FMSketch
-	Info           *model.ColumnInfo
+	CMSketch *CMSketch
+	TopN     *TopN
+	FMSketch *FMSketch
+	Info     *model.ColumnInfo
 	Histogram
 
 	// StatsLoadedStatus indicates the status of column statistics
@@ -54,7 +53,6 @@ func (c *Column) Copy() *Column {
 		StatsVer:   c.StatsVer,
 		IsHandle:   c.IsHandle,
 	}
-	c.LastAnalyzePos.Copy(&nc.LastAnalyzePos)
 	if c.CMSketch != nil {
 		nc.CMSketch = c.CMSketch.Copy()
 	}

pkg/statistics/handle/bootstrap.go

@@ -190,7 +190,6 @@ func (h *Handle) initStatsHistograms4Chunk(is infoschema.InfoSchema, cache stats
 			table.StatsVer = int(statsVer)
 		}
 		id, ndv, nullCount, version, totColSize := row.GetInt64(2), row.GetInt64(3), row.GetInt64(5), row.GetUint64(4), row.GetInt64(7)
-		lastAnalyzePos := row.GetDatum(10, types.NewFieldType(mysql.TypeBlob))
 		tbl, ok := h.TableInfoByID(is, table.PhysicalID)
 		if !ok {
 			// this table has been dropped. but stats meta still exists and wait for being deleted.
@@ -235,7 +234,6 @@ func (h *Handle) initStatsHistograms4Chunk(is infoschema.InfoSchema, cache stats
 				// The LastAnalyzeVersion is added by ALTER table so its value might be 0.
 				table.LastAnalyzeVersion = max(table.LastAnalyzeVersion, version)
 			}
-			lastAnalyzePos.Copy(&index.LastAnalyzePos)
 			table.SetIdx(idxInfo.ID, index)
 			table.ColAndIdxExistenceMap.InsertIndex(idxInfo.ID, statsVer != statistics.Version0)
 		} else {
@@ -258,7 +256,6 @@ func (h *Handle) initStatsHistograms4Chunk(is infoschema.InfoSchema, cache stats
 				IsHandle:   tbl.Meta().PKIsHandle && mysql.HasPriKeyFlag(colInfo.GetFlag()),
 				StatsVer:   statsVer,
 			}
-			lastAnalyzePos.Copy(&col.LastAnalyzePos)
 			table.SetCol(hist.ID, col)
 			table.ColAndIdxExistenceMap.InsertCol(colInfo.ID, statsVer != statistics.Version0 || ndv > 0 || nullCount > 0)
 			if statsVer != statistics.Version0 {
@@ -283,7 +280,7 @@ func (h *Handle) initStatsHistograms4Chunk(is infoschema.InfoSchema, cache stats
 // genInitStatsHistogramsSQL generates the SQL to load all stats_histograms records.
 // We need to read all the records since we need to do initialization of table.ColAndIdxExistenceMap.
 func genInitStatsHistogramsSQL(isPaging bool) string {
-	selectPrefix := "select /*+ ORDER_INDEX(mysql.stats_histograms,tbl) */ HIGH_PRIORITY table_id, is_index, hist_id, distinct_count, version, null_count, cm_sketch, tot_col_size, stats_ver, correlation, last_analyze_pos from mysql.stats_histograms"
+	selectPrefix := "select /*+ ORDER_INDEX(mysql.stats_histograms,tbl) */ 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"
 	orderSuffix := " order by table_id"
 	if !isPaging {
 		return selectPrefix + orderSuffix

pkg/statistics/handle/handletest/statstest/stats_test.go

@@ -301,7 +301,6 @@ func TestInitStats(t *testing.T) {
 	h.Clear()
 	require.NoError(t, h.InitStats(context.Background(), is))
 	table0 := h.GetTableStats(tbl.Meta())
-	require.Equal(t, uint8(0x3), table0.GetIdx(1).LastAnalyzePos.GetBytes()[0])
 	h.Clear()
 	require.NoError(t, h.Update(context.Background(), is))
 	// Index and pk are loaded.
@@ -414,8 +413,6 @@ func initStatsVer2(t *testing.T) {
 	require.True(t, !table0.GetCol(4).IsStatsInitialized())
 	require.True(t, table0.GetCol(5).IsStatsInitialized())
 	require.Equal(t, 2, table0.IdxNum())
-	require.Equal(t, uint8(0x3), table0.GetIdx(1).LastAnalyzePos.GetBytes()[0])
-	require.Equal(t, uint8(0x3), table0.GetIdx(2).LastAnalyzePos.GetBytes()[0])
 	h.Clear()
 	require.NoError(t, h.InitStats(context.Background(), is))
 	table1 := h.GetTableStats(tbl.Meta())

pkg/statistics/handle/storage/read.go

@@ -83,7 +83,7 @@ func statsMetaCountAndModifyCount(
 }
 
 // HistMetaFromStorageWithHighPriority reads the meta info of the histogram from the storage.
-func HistMetaFromStorageWithHighPriority(sctx sessionctx.Context, item *model.TableItemID, possibleColInfo *model.ColumnInfo) (*statistics.Histogram, *types.Datum, int64, error) {
+func HistMetaFromStorageWithHighPriority(sctx sessionctx.Context, item *model.TableItemID, possibleColInfo *model.ColumnInfo) (*statistics.Histogram, int64, error) {
 	isIndex := 0
 	var tp *types.FieldType
 	if item.IsIndex {
@@ -93,21 +93,20 @@ func HistMetaFromStorageWithHighPriority(sctx sessionctx.Context, item *model.Ta
 		tp = &possibleColInfo.FieldType
 	}
 	rows, _, err := util.ExecRows(sctx,
-		"select high_priority distinct_count, version, null_count, tot_col_size, stats_ver, correlation, last_analyze_pos from mysql.stats_histograms where table_id = %? and hist_id = %? and is_index = %?",
+		"select high_priority distinct_count, version, null_count, tot_col_size, stats_ver, correlation from mysql.stats_histograms where table_id = %? and hist_id = %? and is_index = %?",
 		item.TableID,
 		item.ID,
 		isIndex,
 	)
 	if err != nil {
-		return nil, nil, 0, err
+		return nil, 0, err
 	}
 	if len(rows) == 0 {
-		return nil, nil, 0, nil
+		return nil, 0, nil
 	}
 	hist := statistics.NewHistogram(item.ID, rows[0].GetInt64(0), rows[0].GetInt64(2), rows[0].GetUint64(1), tp, chunk.InitialCapacity, rows[0].GetInt64(3))
 	hist.Correlation = rows[0].GetFloat64(5)
-	lastPos := rows[0].GetDatum(6, types.NewFieldType(mysql.TypeBlob))
-	return hist, &lastPos, rows[0].GetInt64(4), nil
+	return hist, rows[0].GetInt64(4), nil
 }
 
 // HistogramFromStorageWithPriority wraps the HistogramFromStorage with the given kv.Priority.
@@ -305,7 +304,6 @@ func indexStatsFromStorage(sctx sessionctx.Context, row chunk.Row, table *statis
 	nullCount := row.GetInt64(5)
 	statsVer := row.GetInt64(7)
 	idx := table.GetIdx(histID)
-	lastAnalyzePos := row.GetDatum(9, types.NewFieldType(mysql.TypeBlob))
 
 	for _, idxInfo := range tableInfo.Indices {
 		if histID != idxInfo.ID {
@@ -341,7 +339,6 @@ func indexStatsFromStorage(sctx sessionctx.Context, row chunk.Row, table *statis
 			if idx.IsAnalyzed() {
 				idx.StatsLoadedStatus = statistics.NewStatsAllEvictedStatus()
 			}
-			lastAnalyzePos.Copy(&idx.LastAnalyzePos)
 			break
 		}
 		if idx == nil || idx.LastUpdateVersion < histVer || loadAll {
@@ -374,7 +371,6 @@ func indexStatsFromStorage(sctx sessionctx.Context, row chunk.Row, table *statis
 			if statsVer != statistics.Version0 {
 				idx.StatsLoadedStatus = statistics.NewStatsFullLoadStatus()
 			}
-			lastAnalyzePos.Copy(&idx.LastAnalyzePos)
 		}
 		break
 	}
@@ -397,7 +393,6 @@ func columnStatsFromStorage(sctx sessionctx.Context, row chunk.Row, table *stati
 	totColSize := row.GetInt64(6)
 	statsVer := row.GetInt64(7)
 	correlation := row.GetFloat64(8)
-	lastAnalyzePos := row.GetDatum(9, types.NewFieldType(mysql.TypeBlob))
 	col := table.GetCol(histID)
 
 	for _, colInfo := range tableInfo.Columns {
@@ -447,7 +442,6 @@ func columnStatsFromStorage(sctx sessionctx.Context, row chunk.Row, table *stati
 			if col.StatsAvailable() {
 				col.StatsLoadedStatus = statistics.NewStatsAllEvictedStatus()
 			}
-			lastAnalyzePos.Copy(&col.LastAnalyzePos)
 			col.Histogram.Correlation = correlation
 			break
 		}
@@ -482,7 +476,6 @@ func columnStatsFromStorage(sctx sessionctx.Context, row chunk.Row, table *stati
 			if col.StatsAvailable() {
 				col.StatsLoadedStatus = statistics.NewStatsFullLoadStatus()
 			}
-			lastAnalyzePos.Copy(&col.LastAnalyzePos)
 			break
 		}
 		if col.TotColSize != totColSize {
@@ -532,7 +525,7 @@ func TableStatsFromStorage(sctx sessionctx.Context, snapshot uint64, tableInfo *
 	table.ModifyCount = modidyCount
 	table.RealtimeCount = realtimeCount
 
-	rows, _, err := util.ExecRows(sctx, "select table_id, is_index, hist_id, distinct_count, version, null_count, tot_col_size, stats_ver, correlation, last_analyze_pos from mysql.stats_histograms where table_id = %?", tableID)
+	rows, _, err := util.ExecRows(sctx, "select table_id, is_index, hist_id, distinct_count, version, null_count, tot_col_size, stats_ver, correlation from mysql.stats_histograms where table_id = %?", tableID)
 	if err != nil {
 		return nil, err
 	}
@@ -559,7 +552,7 @@ func TableStatsFromStorage(sctx sessionctx.Context, snapshot uint64, tableInfo *
 
 // LoadHistogram will load histogram from storage.
 func LoadHistogram(sctx sessionctx.Context, tableID int64, isIndex int, histID int64, tableInfo *model.TableInfo) (*statistics.Histogram, error) {
-	row, _, err := util.ExecRows(sctx, "select distinct_count, version, null_count, tot_col_size, stats_ver, flag, correlation, last_analyze_pos from mysql.stats_histograms where table_id = %? and is_index = %? and hist_id = %?", tableID, isIndex, histID)
+	row, _, err := util.ExecRows(sctx, "select distinct_count, version, null_count, tot_col_size, stats_ver, flag, correlation from mysql.stats_histograms where table_id = %? and is_index = %? and hist_id = %?", tableID, isIndex, histID)
 	if err != nil || len(row) == 0 {
 		return nil, err
 	}
@@ -664,7 +657,7 @@ func loadNeededColumnHistograms(sctx sessionctx.Context, statsHandle statstypes.
 		return nil
 	}
 
-	hg, _, statsVer, err := HistMetaFromStorageWithHighPriority(sctx, &col, colInfo)
+	hg, statsVer, err := HistMetaFromStorageWithHighPriority(sctx, &col, colInfo)
 	if hg == nil || err != nil {
 		asyncload.AsyncLoadHistogramNeededItems.Delete(col)
 		return err
@@ -743,7 +736,7 @@ func loadNeededIndexHistograms(sctx sessionctx.Context, is infoschema.InfoSchema
 		asyncload.AsyncLoadHistogramNeededItems.Delete(idx)
 		return nil
 	}
-	hgMeta, lastAnalyzePos, statsVer, err := HistMetaFromStorageWithHighPriority(sctx, &idx, nil)
+	hgMeta, statsVer, err := HistMetaFromStorageWithHighPriority(sctx, &idx, nil)
 	if hgMeta == nil || err != nil {
 		asyncload.AsyncLoadHistogramNeededItems.Delete(idx)
 		return err
@@ -772,7 +765,6 @@ func loadNeededIndexHistograms(sctx sessionctx.Context, is infoschema.InfoSchema
 		Info: idxInfo, StatsVer: statsVer,
 		PhysicalID:        idx.TableID,
 		StatsLoadedStatus: statistics.NewStatsFullLoadStatus()}
-	lastAnalyzePos.Copy(&idxHist.LastAnalyzePos)
 
 	tbl, ok = statsHandle.Get(idx.TableID)
 	if !ok {

pkg/statistics/handle/storage/save.go

@@ -74,7 +74,7 @@ func saveTopNToStorage(sctx sessionctx.Context, tableID int64, isIndex int, hist
 	return nil
 }
 
-func saveBucketsToStorage(sctx sessionctx.Context, tableID int64, isIndex int, hg *statistics.Histogram) (lastAnalyzePos []byte, err error) {
+func saveBucketsToStorage(sctx sessionctx.Context, tableID int64, isIndex int, hg *statistics.Histogram) (err error) {
 	if hg == nil {
 		return
 	}
@@ -97,9 +97,6 @@ func saveBucketsToStorage(sctx sessionctx.Context, tableID int64, isIndex int, h
 			if err != nil {
 				return
 			}
-			if j == len(hg.Buckets)-1 {
-				lastAnalyzePos = upperBound.GetBytes()
-			}
 			var lowerBound types.Datum
 			lowerBound, err = hg.GetLower(j).ConvertTo(sc.TypeCtx(), types.NewFieldType(mysql.TypeBlob))
 			if err != nil {
@@ -281,16 +278,10 @@ func SaveTableStatsToStorage(sctx sessionctx.Context,
 			if _, err = util.Exec(sctx, "delete from mysql.stats_buckets where table_id = %? and is_index = %? and hist_id = %?", tableID, result.IsIndex, hg.ID); err != nil {
 				return 0, err
 			}
-			var lastAnalyzePos []byte
-			lastAnalyzePos, err = saveBucketsToStorage(sctx, tableID, result.IsIndex, hg)
+			err = saveBucketsToStorage(sctx, tableID, result.IsIndex, hg)
 			if err != nil {
 				return 0, err
 			}
-			if len(lastAnalyzePos) > 0 {
-				if _, err = util.Exec(sctx, "update mysql.stats_histograms set last_analyze_pos = %? where table_id = %? and is_index = %? and hist_id = %?", lastAnalyzePos, tableID, result.IsIndex, hg.ID); err != nil {
-					return 0, err
-				}
-			}
 			if result.IsIndex == 0 {
 				if _, err = util.Exec(sctx, "insert into mysql.column_stats_usage (table_id, column_id, last_analyzed_at) values(%?, %?, current_timestamp()) on duplicate key update last_analyzed_at = values(last_analyzed_at)", tableID, hg.ID); err != nil {
 					return 0, err
@@ -376,16 +367,10 @@ func SaveStatsToStorage(
 	if _, err = util.Exec(sctx, "delete from mysql.stats_buckets where table_id = %? and is_index = %? and hist_id = %?", tableID, isIndex, hg.ID); err != nil {
 		return 0, err
 	}
-	var lastAnalyzePos []byte
-	lastAnalyzePos, err = saveBucketsToStorage(sctx, tableID, isIndex, hg)
+	err = saveBucketsToStorage(sctx, tableID, isIndex, hg)
 	if err != nil {
 		return 0, err
 	}
-	if len(lastAnalyzePos) > 0 {
-		if _, err = util.Exec(sctx, "update mysql.stats_histograms set last_analyze_pos = %? where table_id = %? and is_index = %? and hist_id = %?", lastAnalyzePos, tableID, isIndex, hg.ID); err != nil {
-			return 0, err
-		}
-	}
 	if updateAnalyzeTime && isIndex == 0 {
 		if _, err = util.Exec(sctx, "insert into mysql.column_stats_usage (table_id, column_id, last_analyzed_at) values(%?, %?, current_timestamp()) on duplicate key update last_analyzed_at = current_timestamp()", tableID, hg.ID); err != nil {
 			return 0, err

pkg/statistics/handle/syncload/stats_syncload.go

@@ -404,7 +404,7 @@ func (*statsSyncLoad) readStatsForOneItem(sctx sessionctx.Context, item model.Ta
 	var hg *statistics.Histogram
 	var err error
 	isIndexFlag := int64(0)
-	hg, lastAnalyzePos, statsVer, err := storage.HistMetaFromStorageWithHighPriority(sctx, &item, w.colInfo)
+	hg, statsVer, err := storage.HistMetaFromStorageWithHighPriority(sctx, &item, w.colInfo)
 	if err != nil {
 		return nil, err
 	}
@@ -460,7 +460,6 @@ func (*statsSyncLoad) readStatsForOneItem(sctx sessionctx.Context, item model.Ta
 				idxHist.StatsLoadedStatus = statistics.NewStatsAllEvictedStatus()
 			}
 		}
-		lastAnalyzePos.Copy(&idxHist.LastAnalyzePos)
 		w.idx = idxHist
 	} else {
 		colHist := &statistics.Column{

pkg/statistics/index.go

@@ -27,11 +27,10 @@ import (
 
 // Index represents an index histogram.
 type Index struct {
-	LastAnalyzePos types.Datum
-	CMSketch       *CMSketch
-	TopN           *TopN
-	FMSketch       *FMSketch
-	Info           *model.IndexInfo
+	CMSketch *CMSketch
+	TopN     *TopN
+	FMSketch *FMSketch
+	Info     *model.IndexInfo
 	Histogram
 	StatsLoadedStatus
 	StatsVer int64 // StatsVer is the version of the current stats, used to maintain compatibility
@@ -50,7 +49,6 @@ func (idx *Index) Copy() *Index {
 		PhysicalID: idx.PhysicalID,
 		StatsVer:   idx.StatsVer,
 	}
-	idx.LastAnalyzePos.Copy(&nc.LastAnalyzePos)
 	if idx.CMSketch != nil {
 		nc.CMSketch = idx.CMSketch.Copy()
 	}