statistics: correct behavior of non-lite InitStats and stats sync loa…

…d of no stats column (#57803) (#57943)

close #57804

pkg/statistics/handle/bootstrap.go

@@ -244,15 +244,20 @@ func (h *Handle) initStatsHistograms4Chunk(is infoschema.InfoSchema, cache stats
 				Flag:       row.GetInt64(10),
 				StatsVer:   statsVer,
 			}
-			// primary key column has no stats info, because primary key's is_index is false. so it cannot load the topn
-			col.StatsLoadedStatus = statistics.NewStatsAllEvictedStatus()
 			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 {
 				// The LastAnalyzeVersion is added by ALTER table so its value might be 0.
 				table.LastAnalyzeVersion = max(table.LastAnalyzeVersion, version)
+				// We will also set int primary key's loaded status to evicted.
+				col.StatsLoadedStatus = statistics.NewStatsAllEvictedStatus()
+			} else if col.NDV > 0 || col.NullCount > 0 {
+				// If NDV > 0 or NullCount > 0, we also treat it as the one having its statistics. See the comments of StatsAvailable in column.go.
+				// So we align its status as evicted too.
+				col.StatsLoadedStatus = statistics.NewStatsAllEvictedStatus()
 			}
+			// Otherwise the column's stats is not initialized.
 		}
 	}
 	if table != nil {
@@ -261,8 +266,19 @@ func (h *Handle) initStatsHistograms4Chunk(is infoschema.InfoSchema, cache stats
 	}
 }
 
+// initStatsHistogramsSQLGen 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 initStatsHistogramsSQLGen(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, flag, last_analyze_pos from mysql.stats_histograms"
+	orderSuffix := " order by table_id"
+	if !isPaging {
+		return selectPrefix + orderSuffix
+	}
+	return selectPrefix + " where table_id >= %? and table_id < %?" + orderSuffix
+}
+
 func (h *Handle) initStatsHistogramsLite(ctx context.Context, cache statstypes.StatsCache) error {
-	sql := "select /*+ ORDER_INDEX(mysql.stats_histograms,tbl)*/ HIGH_PRIORITY table_id, is_index, hist_id, distinct_count, version, null_count, tot_col_size, stats_ver, correlation, flag, last_analyze_pos from mysql.stats_histograms order by table_id"
+	sql := initStatsHistogramsSQLGen(false)
 	rc, err := util.Exec(h.initStatsCtx, sql)
 	if err != nil {
 		return errors.Trace(err)
@@ -285,7 +301,7 @@ func (h *Handle) initStatsHistogramsLite(ctx context.Context, cache statstypes.S
 }
 
 func (h *Handle) initStatsHistograms(is infoschema.InfoSchema, cache statstypes.StatsCache) error {
-	sql := "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, flag, last_analyze_pos from mysql.stats_histograms order by table_id"
+	sql := initStatsHistogramsSQLGen(false)
 	rc, err := util.Exec(h.initStatsCtx, sql)
 	if err != nil {
 		return errors.Trace(err)
@@ -319,10 +335,7 @@ func (h *Handle) initStatsHistogramsByPaging(is infoschema.InfoSchema, cache sta
 	}()
 
 	sctx := se.(sessionctx.Context)
-	// Why do we need to add `is_index=1` in the SQL?
-	// because it is aligned to the `initStatsTopN` function, which only loads the topn of the index too.
-	// the other will be loaded by sync load.
-	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 where table_id >= %? and table_id < %? and is_index=1"
+	sql := initStatsHistogramsSQLGen(true)
 	rc, err := util.Exec(sctx, sql, task.StartTid, task.EndTid)
 	if err != nil {
 		return errors.Trace(err)
@@ -401,8 +414,20 @@ func (*Handle) initStatsTopN4Chunk(cache statstypes.StatsCache, iter *chunk.Iter
 	}
 }
 
+// initStatsTopNSQLGen generates the SQL to load all stats_top_n records.
+// We only need to load the indexes' since we only record the existence of columns in ColAndIdxExistenceMap.
+// The stats of the column is not loaded during the bootstrap process.
+func initStatsTopNSQLGen(isPaging bool) string {
+	selectPrefix := "select /*+ ORDER_INDEX(mysql.stats_top_n,tbl) */ HIGH_PRIORITY table_id, hist_id, value, count from mysql.stats_top_n where is_index = 1"
+	orderSuffix := " order by table_id"
+	if !isPaging {
+		return selectPrefix + orderSuffix
+	}
+	return selectPrefix + " and table_id >= %? and table_id < %?" + orderSuffix
+}
+
 func (h *Handle) initStatsTopN(cache statstypes.StatsCache, totalMemory uint64) error {
-	sql := "select /*+ ORDER_INDEX(mysql.stats_top_n,tbl)*/  HIGH_PRIORITY table_id, hist_id, value, count from mysql.stats_top_n where is_index = 1 order by table_id"
+	sql := initStatsTopNSQLGen(false)
 	rc, err := util.Exec(h.initStatsCtx, sql)
 	if err != nil {
 		return errors.Trace(err)
@@ -435,7 +460,7 @@ func (h *Handle) initStatsTopNByPaging(cache statstypes.StatsCache, task initsta
 		}
 	}()
 	sctx := se.(sessionctx.Context)
-	sql := "select HIGH_PRIORITY table_id, hist_id, value, count from mysql.stats_top_n where is_index = 1 and table_id >= %? and table_id < %? order by table_id"
+	sql := initStatsTopNSQLGen(true)
 	rc, err := util.Exec(sctx, sql, task.StartTid, task.EndTid)
 	if err != nil {
 		return errors.Trace(err)
@@ -619,6 +644,18 @@ func (*Handle) initStatsBuckets4Chunk(cache statstypes.StatsCache, iter *chunk.I
 	}
 }
 
+// initStatsBucketsSQLGen generates the SQL to load all stats_top_n records.
+// We only need to load the indexes' since we only record the existence of columns in ColAndIdxExistenceMap.
+// The stats of the column is not loaded during the bootstrap process.
+func initStatsBucketsSQLGen(isPaging bool) string {
+	selectPrefix := "select /*+ ORDER_INDEX(mysql.stats_buckets,tbl) */ HIGH_PRIORITY table_id, is_index, hist_id, count, repeats, lower_bound, upper_bound, ndv from mysql.stats_buckets where is_index=1"
+	orderSuffix := " order by table_id"
+	if !isPaging {
+		return selectPrefix + orderSuffix
+	}
+	return selectPrefix + " and table_id >= %? and table_id < %?" + orderSuffix
+}
+
 func (h *Handle) initStatsBuckets(cache statstypes.StatsCache, totalMemory uint64) error {
 	if isFullCache(cache, totalMemory) {
 		return nil
@@ -629,7 +666,7 @@ func (h *Handle) initStatsBuckets(cache statstypes.StatsCache, totalMemory uint6
 			return errors.Trace(err)
 		}
 	} else {
-		sql := "select /*+ ORDER_INDEX(mysql.stats_buckets,tbl)*/ HIGH_PRIORITY table_id, is_index, hist_id, count, repeats, lower_bound, upper_bound, ndv from mysql.stats_buckets order by table_id, is_index, hist_id, bucket_id"
+		sql := initStatsBucketsSQLGen(false)
 		rc, err := util.Exec(h.initStatsCtx, sql)
 		if err != nil {
 			return errors.Trace(err)
@@ -668,7 +705,7 @@ func (h *Handle) initStatsBucketsByPaging(cache statstypes.StatsCache, task init
 		}
 	}()
 	sctx := se.(sessionctx.Context)
-	sql := "select HIGH_PRIORITY table_id, is_index, hist_id, count, repeats, lower_bound, upper_bound, ndv from mysql.stats_buckets where table_id >= %? and table_id < %? order by table_id, is_index, hist_id, bucket_id"
+	sql := initStatsBucketsSQLGen(true)
 	rc, err := util.Exec(sctx, sql, task.StartTid, task.EndTid)
 	if err != nil {
 		return errors.Trace(err)
@@ -719,8 +756,10 @@ func (h *Handle) initStatsBucketsConcurrency(cache statstypes.StatsCache, totalM
 
 // InitStatsLite initiates the stats cache. The function is liter and faster than InitStats.
 // 1. Basic stats meta data is loaded.(count, modify count, etc.)
-// 2. Column/index stats are loaded. (only histogram)
+// 2. Column/index stats are marked as existing or not by initializing the table.ColAndIdxExistenceMap, based on data from mysql.stats_histograms)
 // 3. TopN, Bucket, FMSketch are not loaded.
+// And to work with auto analyze's needs, we need to read all the tables' stats meta into memory.
+// The sync/async load of the stats or other process haven't done a full initialization of the table.ColAndIdxExistenceMap. So we need to it here.
 func (h *Handle) InitStatsLite(ctx context.Context) (err error) {
 	defer func() {
 		_, err1 := util.Exec(h.initStatsCtx, "commit")
@@ -750,7 +789,10 @@ func (h *Handle) InitStatsLite(ctx context.Context) (err error) {
 
 // InitStats initiates the stats cache.
 // 1. Basic stats meta data is loaded.(count, modify count, etc.)
-// 2. Column/index stats are loaded. (histogram, topn, buckets, FMSketch)
+// 2. Index stats are fully loaded. (histogram, topn, buckets)
+// 2. Column stats are marked as existing or not by initializing the table.ColAndIdxExistenceMap, based on data from mysql.stats_histograms)
+// To work with auto-analyze's needs, we need to read all stats meta info into memory.
+// The sync/async load of the stats or other process haven't done a full initialization of the table.ColAndIdxExistenceMap. So we need to it here.
 func (h *Handle) InitStats(ctx context.Context, is infoschema.InfoSchema) (err error) {
 	totalMemory, err := memory.MemTotal()
 	if err != nil {

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

@@ -305,6 +305,9 @@ func TestInitStats(t *testing.T) {
 	require.NoError(t, h.Update(context.Background(), is))
 	// Index and pk are loaded.
 	needed := fmt.Sprintf(`Table:%v RealtimeCount:6
+column:1 ndv:6 totColSize:0
+column:2 ndv:6 totColSize:6
+column:3 ndv:6 totColSize:6
 index:1 ndv:6
 num: 1 lower_bound: 1 upper_bound: 1 repeats: 1 ndv: 0
 num: 1 lower_bound: 2 upper_bound: 2 repeats: 1 ndv: 0
@@ -363,7 +366,7 @@ func TestInitStatsVer2(t *testing.T) {
 	}()
 	config.GetGlobalConfig().Performance.LiteInitStats = false
 	config.GetGlobalConfig().Performance.ConcurrentlyInitStats = false
-	initStatsVer2(t, false)
+	initStatsVer2(t)
 }
 
 func TestInitStatsVer2Concurrency(t *testing.T) {
@@ -375,18 +378,21 @@ func TestInitStatsVer2Concurrency(t *testing.T) {
 	}()
 	config.GetGlobalConfig().Performance.LiteInitStats = false
 	config.GetGlobalConfig().Performance.ConcurrentlyInitStats = true
-	initStatsVer2(t, true)
+	initStatsVer2(t)
 }
 
-func initStatsVer2(t *testing.T, isConcurrency bool) {
+func initStatsVer2(t *testing.T) {
 	store, dom := testkit.CreateMockStoreAndDomain(t)
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
 	tk.MustExec("set @@session.tidb_analyze_version=2")
-	tk.MustExec("create table t(a int, b int, c int, index idx(a), index idxab(a, b))")
+	tk.MustExec("create table t(a int, b int, c int, d int, index idx(a), index idxab(a, b))")
+	dom.StatsHandle().HandleDDLEvent(<-dom.StatsHandle().DDLEventCh())
 	analyzehelper.TriggerPredicateColumnsCollection(t, tk, store, "t", "c")
-	tk.MustExec("insert into t values(1, 1, 1), (2, 2, 2), (3, 3, 3), (4, 4, 4), (4, 4, 4), (4, 4, 4)")
+	tk.MustExec("insert into t values(1, 1, 1, 1), (2, 2, 2, 2), (3, 3, 3, 3), (4, 4, 4, 4), (4, 4, 4, 4), (4, 4, 4, 4)")
 	tk.MustExec("analyze table t with 2 topn, 3 buckets")
+	tk.MustExec("alter table t add column e int default 1")
+	dom.StatsHandle().HandleDDLEvent(<-dom.StatsHandle().DDLEventCh())
 	h := dom.StatsHandle()
 	is := dom.InfoSchema()
 	tbl, err := is.TableByName(context.Background(), model.NewCIStr("test"), model.NewCIStr("t"))
@@ -398,16 +404,15 @@ func initStatsVer2(t *testing.T, isConcurrency bool) {
 	h.Clear()
 	require.NoError(t, h.InitStats(context.Background(), is))
 	table0 := h.GetTableStats(tbl.Meta())
-	if isConcurrency {
-		require.Equal(t, uint8(0x3), table0.GetIdx(1).LastAnalyzePos.GetBytes()[0])
-		require.Equal(t, uint8(0x3), table0.GetIdx(2).LastAnalyzePos.GetBytes()[0])
-	} else {
-		require.Equal(t, uint8(0x33), table0.GetCol(1).LastAnalyzePos.GetBytes()[0])
-		require.Equal(t, uint8(0x33), table0.GetCol(2).LastAnalyzePos.GetBytes()[0])
-		require.Equal(t, uint8(0x33), table0.GetCol(3).LastAnalyzePos.GetBytes()[0])
-		require.Equal(t, uint8(0x3), table0.GetIdx(1).LastAnalyzePos.GetBytes()[0])
-		require.Equal(t, uint8(0x3), table0.GetIdx(2).LastAnalyzePos.GetBytes()[0])
-	}
+	require.Equal(t, 5, table0.ColNum())
+	require.True(t, table0.GetCol(1).IsAllEvicted())
+	require.True(t, table0.GetCol(2).IsAllEvicted())
+	require.True(t, table0.GetCol(3).IsAllEvicted())
+	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/syncload/BUILD.bazel

@@ -17,7 +17,6 @@ go_library(
         "//pkg/statistics",
         "//pkg/statistics/handle/storage",
         "//pkg/statistics/handle/types",
-        "//pkg/table",
         "//pkg/types",
         "//pkg/util",
         "//pkg/util/intest",
@@ -35,7 +34,7 @@ go_test(
     srcs = ["stats_syncload_test.go"],
     flaky = True,
     race = "on",
-    shard_count = 6,
+    shard_count = 7,
     deps = [
         ":syncload",
         "//pkg/config",

pkg/statistics/handle/syncload/stats_syncload.go

@@ -33,7 +33,6 @@ import (
 	"github.com/pingcap/tidb/pkg/statistics"
 	"github.com/pingcap/tidb/pkg/statistics/handle/storage"
 	statstypes "github.com/pingcap/tidb/pkg/statistics/handle/types"
-	"github.com/pingcap/tidb/pkg/table"
 	"github.com/pingcap/tidb/pkg/types"
 	"github.com/pingcap/tidb/pkg/util"
 	"github.com/pingcap/tidb/pkg/util/intest"
@@ -305,30 +304,31 @@ func (s *statsSyncLoad) handleOneItemTask(task *statstypes.NeededItemTask) (err
 		}
 	}()
 	item := task.Item.TableItemID
-	tbl, ok := s.statsHandle.Get(item.TableID)
+	statsTbl, ok := s.statsHandle.Get(item.TableID)
 
 	if !ok {
 		return nil
 	}
 	is := sctx.GetDomainInfoSchema().(infoschema.InfoSchema)
-	tblInfo, ok := s.statsHandle.TableInfoByID(is, item.TableID)
+	tbl, ok := s.statsHandle.TableInfoByID(is, item.TableID)
 	if !ok {
 		return nil
 	}
-	isPkIsHandle := tblInfo.Meta().PKIsHandle
+	tblInfo := tbl.Meta()
+	isPkIsHandle := tblInfo.PKIsHandle
 	wrapper := &statsWrapper{}
 	if item.IsIndex {
-		index, loadNeeded := tbl.IndexIsLoadNeeded(item.ID)
+		index, loadNeeded := statsTbl.IndexIsLoadNeeded(item.ID)
 		if !loadNeeded {
 			return nil
 		}
 		if index != nil {
 			wrapper.idxInfo = index.Info
 		} else {
-			wrapper.idxInfo = tblInfo.Meta().FindIndexByID(item.ID)
+			wrapper.idxInfo = tblInfo.FindIndexByID(item.ID)
 		}
 	} else {
-		col, loadNeeded, analyzed := tbl.ColumnIsLoadNeeded(item.ID, task.Item.FullLoad)
+		col, loadNeeded, analyzed := statsTbl.ColumnIsLoadNeeded(item.ID, task.Item.FullLoad)
 		if !loadNeeded {
 			return nil
 		}
@@ -337,7 +337,7 @@ func (s *statsSyncLoad) handleOneItemTask(task *statstypes.NeededItemTask) (err
 		} else {
 			// Now, we cannot init the column info in the ColAndIdxExistenceMap when to disable lite-init-stats.
 			// so we have to get the column info from the domain.
-			wrapper.colInfo = tblInfo.Meta().GetColumnByID(item.ID)
+			wrapper.colInfo = tblInfo.GetColumnByID(item.ID)
 		}
 		// If this column is not analyzed yet and we don't have it in memory.
 		// We create a fake one for the pseudo estimation.
@@ -393,7 +393,8 @@ func (*statsSyncLoad) readStatsForOneItem(sctx sessionctx.Context, item model.Ta
 	}
 	if hg == nil {
 		logutil.BgLogger().Warn("fail to get hist meta for this histogram, possibly a deleted one", zap.Int64("table_id", item.TableID),
-			zap.Int64("hist_id", item.ID), zap.Bool("is_index", item.IsIndex))
+			zap.Int64("hist_id", item.ID), zap.Bool("is_index", item.IsIndex),
+		)
 		return nil, errGetHistMeta
 	}
 	if item.IsIndex {
@@ -543,7 +544,7 @@ func (*statsSyncLoad) writeToResultChan(resultCh chan stmtctx.StatsLoadResult, r
 }
 
 // updateCachedItem updates the column/index hist to global statsCache.
-func (s *statsSyncLoad) updateCachedItem(tblInfo table.Table, item model.TableItemID, colHist *statistics.Column, idxHist *statistics.Index, fullLoaded bool) (updated bool) {
+func (s *statsSyncLoad) updateCachedItem(tblInfo *model.TableInfo, item model.TableItemID, colHist *statistics.Column, idxHist *statistics.Index, fullLoaded bool) (updated bool) {
 	s.StatsLoad.Lock()
 	defer s.StatsLoad.Unlock()
 	// Reload the latest stats cache, otherwise the `updateStatsCache` may fail with high probability, because functions
@@ -555,13 +556,13 @@ func (s *statsSyncLoad) updateCachedItem(tblInfo table.Table, item model.TableIt
 	if !tbl.ColAndIdxExistenceMap.Checked() {
 		tbl = tbl.Copy()
 		for _, col := range tbl.HistColl.GetColSlice() {
-			if tblInfo.Meta().FindColumnByID(col.ID) == nil {
+			if tblInfo.FindColumnByID(col.ID) == nil {
 				tbl.HistColl.DelCol(col.ID)
 				tbl.ColAndIdxExistenceMap.DeleteColAnalyzed(col.ID)
 			}
 		}
 		for _, idx := range tbl.HistColl.GetIdxSlice() {
-			if tblInfo.Meta().FindIndexByID(idx.ID) == nil {
+			if tblInfo.FindIndexByID(idx.ID) == nil {
 				tbl.HistColl.DelIdx(idx.ID)
 				tbl.ColAndIdxExistenceMap.DeleteIdxAnalyzed(idx.ID)
 			}