planner: remove StatsHandler.mu (pingcap#47082)

ref pingcap#46905

domain/domain.go

@@ -2329,10 +2329,6 @@ func (do *Domain) loadStatsWorker() {
 	for {
 		select {
 		case <-loadTicker.C:
-			err = statsHandle.RefreshVars()
-			if err != nil {
-				logutil.BgLogger().Debug("refresh variables failed", zap.Error(err))
-			}
 			err = statsHandle.Update(do.InfoSchema())
 			if err != nil {
 				logutil.BgLogger().Debug("update stats info failed", zap.Error(err))

executor/infoschema_reader_test.go

@@ -433,7 +433,6 @@ func TestPartitionsTable(t *testing.T) {
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("USE test;")
 	testkit.WithPruneMode(tk, variable.Static, func() {
-		require.NoError(t, h.RefreshVars())
 		tk.MustExec("DROP TABLE IF EXISTS `test_partitions`;")
 		tk.MustExec(`CREATE TABLE test_partitions (a int, b int, c varchar(5), primary key(a), index idx(c)) PARTITION BY RANGE (a) (PARTITION p0 VALUES LESS THAN (6), PARTITION p1 VALUES LESS THAN (11), PARTITION p2 VALUES LESS THAN (16));`)
 		require.NoError(t, h.HandleDDLEvent(<-h.DDLEventCh()))

statistics/handle/BUILD.bazel

@@ -41,7 +41,6 @@ go_library(
         "//util/logutil",
         "//util/mathutil",
         "//util/sqlexec",
-        "//util/syncutil",
         "//util/timeutil",
         "@com_github_ngaut_pools//:pools",
         "@com_github_pingcap_errors//:errors",

statistics/handle/handle.go

@@ -48,7 +48,6 @@ import (
 	"github.com/pingcap/tidb/util/logutil"
 	"github.com/pingcap/tidb/util/mathutil"
 	"github.com/pingcap/tidb/util/sqlexec"
-	"github.com/pingcap/tidb/util/syncutil"
 	"github.com/tiancaiamao/gp"
 	"github.com/tikv/client-go/v2/oracle"
 	atomic2 "go.uber.org/atomic"
@@ -95,11 +94,6 @@ type Handle struct {
 	// StatsLoad is used to load stats concurrently
 	StatsLoad StatsLoad
 
-	mu struct {
-		ctx sessionctx.Context
-		syncutil.RWMutex
-	}
-
 	schemaMu struct {
 		// pid2tid is the map from partition ID to table ID.
 		pid2tid map[int64]int64
@@ -160,26 +154,18 @@ func (h *Handle) execRestrictedSQLWithSnapshot(ctx context.Context, sql string,
 
 // Clear the statsCache, only for test.
 func (h *Handle) Clear() {
-	// TODO: Here h.mu seems to protect all the fields of Handle. Is is reasonable?
-	h.mu.Lock()
 	cache, err := cache.NewStatsCache()
 	if err != nil {
 		logutil.BgLogger().Warn("create stats cache failed", zap.Error(err))
-		h.mu.Unlock()
 		return
 	}
 	h.statsCache.Replace(cache)
 	for len(h.ddlEventCh) > 0 {
 		<-h.ddlEventCh
 	}
-	h.mu.ctx.GetSessionVars().InitChunkSize = 1
-	h.mu.ctx.GetSessionVars().MaxChunkSize = 1
-	h.mu.ctx.GetSessionVars().EnableChunkRPC = false
-	h.mu.ctx.GetSessionVars().SetProjectionConcurrency(0)
 	h.listHead.ClearForTest()
 	h.tableDelta.reset()
 	h.statsUsage.reset()
-	h.mu.Unlock()
 }
 
 type sessionPool interface {
@@ -188,7 +174,7 @@ type sessionPool interface {
 }
 
 // NewHandle creates a Handle for update stats.
-func NewHandle(ctx, initStatsCtx sessionctx.Context, lease time.Duration, pool sessionPool, tracker sessionctx.SysProcTracker, autoAnalyzeProcIDGetter func() uint64) (*Handle, error) {
+func NewHandle(_, initStatsCtx sessionctx.Context, lease time.Duration, pool sessionPool, tracker sessionctx.SysProcTracker, autoAnalyzeProcIDGetter func() uint64) (*Handle, error) {
 	cfg := config.GetGlobalConfig()
 	gpool := gp.New(math.MaxInt16, time.Minute)
 	handle := &Handle{
@@ -203,7 +189,6 @@ func NewHandle(ctx, initStatsCtx sessionctx.Context, lease time.Duration, pool s
 	}
 	handle.initStatsCtx = initStatsCtx
 	handle.lease.Store(lease)
-	handle.mu.ctx = ctx
 	statsCache, err := cache.NewStatsCachePointer()
 	if err != nil {
 		return nil, err
@@ -215,10 +200,6 @@ func NewHandle(ctx, initStatsCtx sessionctx.Context, lease time.Duration, pool s
 	handle.StatsLoad.NeededItemsCh = make(chan *NeededItemTask, cfg.Performance.StatsLoadQueueSize)
 	handle.StatsLoad.TimeoutItemsCh = make(chan *NeededItemTask, cfg.Performance.StatsLoadQueueSize)
 	handle.StatsLoad.WorkingColMap = map[model.TableItemID][]chan stmtctx.StatsLoadResult{}
-	err = handle.RefreshVars()
-	if err != nil {
-		return nil, err
-	}
 	return handle, nil
 }
 
@@ -1539,13 +1520,6 @@ func (h *Handle) SaveExtendedStatsToStorage(tableID int64, extStats *statistics.
 	return nil
 }
 
-// RefreshVars uses to pull PartitionPruneMethod vars from kv storage.
-func (h *Handle) RefreshVars() error {
-	h.mu.Lock()
-	defer h.mu.Unlock()
-	return UpdateSCtxVarsForStats(h.mu.ctx)
-}
-
 // CheckAnalyzeVersion checks whether all the statistics versions of this table's columns and indexes are the same.
 func (h *Handle) CheckAnalyzeVersion(tblInfo *model.TableInfo, physicalIDs []int64, version *int) bool {
 	// We simply choose one physical id to get its stats.

statistics/handle/update.go

@@ -888,7 +888,7 @@ func (h *Handle) autoAnalyzeTable(tblInfo *model.TableInfo, statsTbl *statistics
 			return false
 		}
 		logutil.BgLogger().Info("auto analyze triggered", zap.String("category", "stats"), zap.String("sql", escaped), zap.String("reason", reason))
-		tableStatsVer, err := h.getCurrentAnalyzeVersion()
+		tableStatsVer, err := h.GetCurrentAnalyzeVersion()
 		if err != nil {
 			logutil.BgLogger().Error("fail to get analyze version", zap.String("category", "stats"), zap.Error(err))
 			return false
@@ -906,7 +906,7 @@ func (h *Handle) autoAnalyzeTable(tblInfo *model.TableInfo, statsTbl *statistics
 				return false
 			}
 			logutil.BgLogger().Info("auto analyze for unanalyzed", zap.String("category", "stats"), zap.String("sql", escaped))
-			tableStatsVer, err := h.getCurrentAnalyzeVersion()
+			tableStatsVer, err := h.GetCurrentAnalyzeVersion()
 			if err != nil {
 				logutil.BgLogger().Error("fail to get analyze version", zap.String("category", "stats"), zap.Error(err))
 				return false
@@ -919,7 +919,8 @@ func (h *Handle) autoAnalyzeTable(tblInfo *model.TableInfo, statsTbl *statistics
 	return false
 }
 
-func (h *Handle) getCurrentAnalyzeVersion() (int, error) {
+// GetCurrentAnalyzeVersion returns the current analyze version.
+func (h *Handle) GetCurrentAnalyzeVersion() (int, error) {
 	se, err := h.pool.Get()
 	if err != nil {
 		return 0, err
@@ -932,7 +933,7 @@ func (h *Handle) getCurrentAnalyzeVersion() (int, error) {
 	return sctx.GetSessionVars().AnalyzeVersion, nil
 }
 
-// GetCurrentPruneMode returns the current latest partitioning talbe prune mode.
+// GetCurrentPruneMode returns the current latest partitioning table prune mode.
 func (h *Handle) GetCurrentPruneMode() (string, error) {
 	se, err := h.pool.Get()
 	if err != nil {
@@ -947,7 +948,7 @@ func (h *Handle) GetCurrentPruneMode() (string, error) {
 }
 
 func (h *Handle) autoAnalyzePartitionTableInDynamicMode(tblInfo *model.TableInfo, partitionDefs []model.PartitionDefinition, db string, ratio float64, analyzeSnapshot bool) bool {
-	tableStatsVer, err := h.getCurrentAnalyzeVersion()
+	tableStatsVer, err := h.GetCurrentAnalyzeVersion()
 	if err != nil {
 		logutil.BgLogger().Info("fail to get analyze version", zap.String("category", "stats"),
 			zap.String("table", tblInfo.Name.String()),

statistics/handle/updatetest/BUILD.bazel

@@ -8,11 +8,12 @@ go_test(
         "update_test.go",
     ],
     flaky = True,
-    shard_count = 27,
+    shard_count = 28,
     deps = [
         "//parser/model",
         "//parser/mysql",
         "//planner/cardinality",
+        "//sessionctx",
         "//sessionctx/variable",
         "//statistics",
         "//statistics/handle",

statistics/handle/updatetest/update_test.go

@@ -25,6 +25,7 @@ import (
 	"github.com/pingcap/tidb/parser/model"
 	"github.com/pingcap/tidb/parser/mysql"
 	"github.com/pingcap/tidb/planner/cardinality"
+	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/statistics"
 	"github.com/pingcap/tidb/statistics/handle"
@@ -299,7 +300,6 @@ func TestUpdatePartition(t *testing.T) {
 	testKit.MustQuery("select @@tidb_partition_prune_mode").Check(testkit.Rows(pruneMode))
 	testKit.MustExec("use test")
 	testkit.WithPruneMode(testKit, variable.Static, func() {
-		err := dom.StatsHandle().RefreshVars()
 		require.NoError(t, err)
 		testKit.MustExec("drop table if exists t")
 		createTable := `CREATE TABLE t (a int, b char(5)) PARTITION BY RANGE (a) (PARTITION p0 VALUES LESS THAN (6),PARTITION p1 VALUES LESS THAN (11))`
@@ -481,7 +481,6 @@ func TestAutoUpdatePartition(t *testing.T) {
 		tableInfo := tbl.Meta()
 		pi := tableInfo.GetPartitionInfo()
 		h := do.StatsHandle()
-		require.NoError(t, h.RefreshVars())
 
 		require.NoError(t, h.Update(is))
 		stats := h.GetPartitionStats(tableInfo, pi.Definitions[0].ID)
@@ -1004,6 +1003,47 @@ func TestMergeTopN(t *testing.T) {
 	}
 }
 
+func TestStatsVariables(t *testing.T) {
+	store, dom := testkit.CreateMockStoreAndDomain(t)
+	tk := testkit.NewTestKit(t, store)
+	h := dom.StatsHandle()
+	sctx := tk.Session().(sessionctx.Context)
+
+	pruneMode, err := h.GetCurrentPruneMode()
+	require.NoError(t, err)
+	require.Equal(t, string(variable.Dynamic), pruneMode)
+	analyzeVer, err := h.GetCurrentAnalyzeVersion()
+	require.NoError(t, err)
+	require.Equal(t, 2, analyzeVer)
+	err = handle.UpdateSCtxVarsForStats(sctx)
+	require.NoError(t, err)
+	require.Equal(t, 2, sctx.GetSessionVars().AnalyzeVersion)
+	require.Equal(t, true, sctx.GetSessionVars().EnableHistoricalStats)
+	require.Equal(t, string(variable.Dynamic), sctx.GetSessionVars().PartitionPruneMode.Load())
+	require.Equal(t, false, sctx.GetSessionVars().EnableAnalyzeSnapshot)
+	require.Equal(t, true, sctx.GetSessionVars().SkipMissingPartitionStats)
+
+	tk.MustExec(`set global tidb_analyze_version=1`)
+	tk.MustExec(`set global tidb_partition_prune_mode='static'`)
+	tk.MustExec(`set global tidb_enable_historical_stats=0`)
+	tk.MustExec(`set global tidb_enable_analyze_snapshot=1`)
+	tk.MustExec(`set global tidb_skip_missing_partition_stats=0`)
+
+	pruneMode, err = h.GetCurrentPruneMode()
+	require.NoError(t, err)
+	require.Equal(t, string(variable.Static), pruneMode)
+	analyzeVer, err = h.GetCurrentAnalyzeVersion()
+	require.NoError(t, err)
+	require.Equal(t, 1, analyzeVer)
+	err = handle.UpdateSCtxVarsForStats(sctx)
+	require.NoError(t, err)
+	require.Equal(t, 1, sctx.GetSessionVars().AnalyzeVersion)
+	require.Equal(t, false, sctx.GetSessionVars().EnableHistoricalStats)
+	require.Equal(t, string(variable.Static), sctx.GetSessionVars().PartitionPruneMode.Load())
+	require.Equal(t, true, sctx.GetSessionVars().EnableAnalyzeSnapshot)
+	require.Equal(t, false, sctx.GetSessionVars().SkipMissingPartitionStats)
+}
+
 func TestAutoUpdatePartitionInDynamicOnlyMode(t *testing.T) {
 	store, dom := testkit.CreateMockStoreAndDomain(t)
 	testKit := testkit.NewTestKit(t, store)
@@ -1020,7 +1060,6 @@ func TestAutoUpdatePartitionInDynamicOnlyMode(t *testing.T) {
 		do := dom
 		is := do.InfoSchema()
 		h := do.StatsHandle()
-		require.NoError(t, h.RefreshVars())
 		require.NoError(t, h.HandleDDLEvent(<-h.DDLEventCh()))
 
 		testKit.MustExec("insert into t values (1, 'a'), (2, 'b'), (11, 'c'), (12, 'd'), (21, 'e'), (22, 'f')")