statistics: support dropping partition/global level statistics

executor/simple.go

@@ -1353,10 +1353,13 @@ func (e *SimpleExec) executeAlterInstance(s *ast.AlterInstanceStmt) error {
 
 func (e *SimpleExec) executeDropStats(s *ast.DropStatsStmt) error {
 	h := domain.GetDomain(e.ctx).StatsHandle()
-	err := h.DeleteTableStatsFromKV(s.Table.TableInfo.ID)
+	ids, _, err := core.GetPhysicalIDsAndPartitionNames(s.Table.TableInfo, s.PartitionNames)
 	if err != nil {
 		return err
 	}
+	if err := h.DeleteTableStatsFromKV(ids); err != nil {
+		return err
+	}
 	return h.Update(infoschema.GetInfoSchema(e.ctx))
 }
 

executor/simple_test.go

@@ -29,6 +29,7 @@ import (
 	"github.com/pingcap/tidb/planner/core"
 	"github.com/pingcap/tidb/session"
 	"github.com/pingcap/tidb/sessionctx"
+	"github.com/pingcap/tidb/statistics/handle"
 	"github.com/pingcap/tidb/store/mockstore"
 	"github.com/pingcap/tidb/util"
 	"github.com/pingcap/tidb/util/testkit"
@@ -599,6 +600,45 @@ func (s *testFlushSuite) TestFlushPrivilegesPanic(c *C) {
 	tk.MustExec("FLUSH PRIVILEGES")
 }
 
+func (s *testSuite3) TestDropPartitionStats(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+	tk.MustExec(`create table t (
+	a int,
+	key(a)
+)
+partition by range (a) (
+	partition p0 values less than (10),
+	partition p1 values less than (20)
+)`)
+	tk.MustExec("set @@tidb_partition_prune_mode='dynamic'")
+	tk.MustExec("insert into t values (1), (5), (11), (15)")
+	c.Assert(s.domain.StatsHandle().DumpStatsDeltaToKV(handle.DumpAll), IsNil)
+
+	checkPartitionStats := func(names ...string) {
+		rs := tk.MustQuery("show stats_meta").Rows()
+		c.Assert(len(rs), Equals, len(names))
+		for i := range names {
+			c.Assert(rs[i][2].(string), Equals, names[i])
+		}
+	}
+
+	tk.MustExec("analyze table t")
+	checkPartitionStats("global", "p0", "p1")
+
+	tk.MustExec("drop stats t partition p0")
+	checkPartitionStats("global", "p1")
+
+	tk.MustExec("drop stats t partition global")
+	checkPartitionStats("p1")
+
+	tk.MustExec("analyze table t")
+	checkPartitionStats("global", "p0", "p1")
+
+	tk.MustExec("drop stats t partition p0, p1")
+	checkPartitionStats("global")
+}
+
 func (s *testSuite3) TestDropStats(c *C) {
 	testKit := testkit.NewTestKit(c, s.store)
 	testKit.MustExec("use test")

go.mod

@@ -46,7 +46,7 @@ require (
 	github.com/pingcap/goleveldb v0.0.0-20191226122134-f82aafb29989
 	github.com/pingcap/kvproto v0.0.0-20210219064844-c1844a4775d6
 	github.com/pingcap/log v0.0.0-20201112100606-8f1e84a3abc8
-	github.com/pingcap/parser v0.0.0-20210224050355-ce3c7711a45f
+	github.com/pingcap/parser v0.0.0-20210301085222-267e02a2fc12
 	github.com/pingcap/sysutil v0.0.0-20210221112134-a07bda3bde99
 	github.com/pingcap/tidb-tools v4.0.9-0.20201127090955-2707c97b3853+incompatible
 	github.com/pingcap/tipb v0.0.0-20210220073817-777cefd7ea62

go.sum

@@ -414,8 +414,8 @@ github.com/pingcap/log v0.0.0-20200117041106-d28c14d3b1cd/go.mod h1:4rbK1p9ILyIf
 github.com/pingcap/log v0.0.0-20200511115504-543df19646ad/go.mod h1:4rbK1p9ILyIfb6hU7OG2CiWSqMXnp3JMbiaVJ6mvoY8=
 github.com/pingcap/log v0.0.0-20201112100606-8f1e84a3abc8 h1:M+DNpOu/I3uDmwee6vcnoPd6GgSMqND4gxvDQ/W584U=
 github.com/pingcap/log v0.0.0-20201112100606-8f1e84a3abc8/go.mod h1:4rbK1p9ILyIfb6hU7OG2CiWSqMXnp3JMbiaVJ6mvoY8=
-github.com/pingcap/parser v0.0.0-20210224050355-ce3c7711a45f h1:pifEcAWoLMCwNcaUuXWyDOjmh1MZKnkffC+WTTmAr6A=
-github.com/pingcap/parser v0.0.0-20210224050355-ce3c7711a45f/go.mod h1:GbEr2PgY72/4XqPZzmzstlOU/+il/wrjeTNFs6ihsSE=
+github.com/pingcap/parser v0.0.0-20210301085222-267e02a2fc12 h1:o1wt7CTaX1gXxpM2rPHdw8C4QjYlpAz7sh9joIPfaGA=
+github.com/pingcap/parser v0.0.0-20210301085222-267e02a2fc12/go.mod h1:GbEr2PgY72/4XqPZzmzstlOU/+il/wrjeTNFs6ihsSE=
 github.com/pingcap/sysutil v0.0.0-20200206130906-2bfa6dc40bcd/go.mod h1:EB/852NMQ+aRKioCpToQ94Wl7fktV+FNnxf3CX/TTXI=
 github.com/pingcap/sysutil v0.0.0-20210221112134-a07bda3bde99 h1:/ogXgm4guJzow4UafiyXZ6ciAIPzxImaXYiFvTpKzKY=
 github.com/pingcap/sysutil v0.0.0-20210221112134-a07bda3bde99/go.mod h1:EB/852NMQ+aRKioCpToQ94Wl7fktV+FNnxf3CX/TTXI=

planner/core/planbuilder.go

@@ -40,6 +40,7 @@ import (
 	"github.com/pingcap/tidb/sessionctx/stmtctx"
 	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/statistics"
+	"github.com/pingcap/tidb/statistics/handle"
 	"github.com/pingcap/tidb/store/tikv"
 	"github.com/pingcap/tidb/table"
 	"github.com/pingcap/tidb/types"
@@ -1598,7 +1599,8 @@ func BuildHandleColsForAnalyze(ctx sessionctx.Context, tblInfo *model.TableInfo)
 	return handleCols
 }
 
-func getPhysicalIDsAndPartitionNames(tblInfo *model.TableInfo, partitionNames []model.CIStr) ([]int64, []string, error) {
+// GetPhysicalIDsAndPartitionNames returns physical IDs and names of these partitions.
+func GetPhysicalIDsAndPartitionNames(tblInfo *model.TableInfo, partitionNames []model.CIStr) ([]int64, []string, error) {
 	pi := tblInfo.GetPartitionInfo()
 	if pi == nil {
 		if len(partitionNames) != 0 {
@@ -1628,6 +1630,11 @@ func getPhysicalIDsAndPartitionNames(tblInfo *model.TableInfo, partitionNames []
 			}
 		}
 		if !found {
+			if name.L == handle.TiDBGlobalStats {
+				ids = append(ids, tblInfo.ID)
+				names = append(names, handle.TiDBGlobalStats)
+				continue
+			}
 			return nil, nil, fmt.Errorf("can not found the specified partition name %s in the table definition", name.O)
 		}
 	}
@@ -1644,7 +1651,7 @@ func (b *PlanBuilder) buildAnalyzeTable(as *ast.AnalyzeTableStmt, opts map[ast.A
 			return nil, errors.Errorf("analyze sequence %s is not supported now.", tbl.Name.O)
 		}
 		idxInfo, colInfo := getColsInfo(tbl)
-		physicalIDs, names, err := getPhysicalIDsAndPartitionNames(tbl.TableInfo, as.PartitionNames)
+		physicalIDs, names, err := GetPhysicalIDsAndPartitionNames(tbl.TableInfo, as.PartitionNames)
 		if err != nil {
 			return nil, err
 		}
@@ -1714,7 +1721,7 @@ func (b *PlanBuilder) buildAnalyzeTable(as *ast.AnalyzeTableStmt, opts map[ast.A
 func (b *PlanBuilder) buildAnalyzeIndex(as *ast.AnalyzeTableStmt, opts map[ast.AnalyzeOptionType]uint64, version int) (Plan, error) {
 	p := &Analyze{Opts: opts}
 	tblInfo := as.TableNames[0].TableInfo
-	physicalIDs, names, err := getPhysicalIDsAndPartitionNames(tblInfo, as.PartitionNames)
+	physicalIDs, names, err := GetPhysicalIDsAndPartitionNames(tblInfo, as.PartitionNames)
 	if err != nil {
 		return nil, err
 	}
@@ -1774,7 +1781,7 @@ func (b *PlanBuilder) buildAnalyzeIndex(as *ast.AnalyzeTableStmt, opts map[ast.A
 func (b *PlanBuilder) buildAnalyzeAllIndex(as *ast.AnalyzeTableStmt, opts map[ast.AnalyzeOptionType]uint64, version int) (Plan, error) {
 	p := &Analyze{Opts: opts}
 	tblInfo := as.TableNames[0].TableInfo
-	physicalIDs, names, err := getPhysicalIDsAndPartitionNames(tblInfo, as.PartitionNames)
+	physicalIDs, names, err := GetPhysicalIDsAndPartitionNames(tblInfo, as.PartitionNames)
 	if err != nil {
 		return nil, err
 	}

statistics/handle/gc.go

@@ -68,7 +68,7 @@ func (h *Handle) gcTableStats(is infoschema.InfoSchema, physicalID int64) error
 	tbl, ok := h.getTableByPhysicalID(is, physicalID)
 	h.mu.Unlock()
 	if !ok {
-		return errors.Trace(h.DeleteTableStatsFromKV(physicalID))
+		return errors.Trace(h.DeleteTableStatsFromKV([]int64{physicalID}))
 	}
 	tblInfo := tbl.Meta()
 	for _, row := range rows {
@@ -171,7 +171,8 @@ func (h *Handle) deleteHistStatsFromKV(physicalID int64, histID int64, isIndex i
 }
 
 // DeleteTableStatsFromKV deletes table statistics from kv.
-func (h *Handle) DeleteTableStatsFromKV(physicalID int64) (err error) {
+// A statsID refers to statistic of a table or a partition.
+func (h *Handle) DeleteTableStatsFromKV(statsIDs []int64) (err error) {
 	h.mu.Lock()
 	defer h.mu.Unlock()
 	exec := h.mu.ctx.(sqlexec.SQLExecutor)
@@ -188,24 +189,26 @@ func (h *Handle) DeleteTableStatsFromKV(physicalID int64) (err error) {
 	}
 	ctx := context.Background()
 	startTS := txn.StartTS()
-	// We only update the version so that other tidb will know that this table is deleted.
-	if _, err = exec.ExecuteInternal(ctx, "update mysql.stats_meta set version = %? where table_id = %? ", startTS, physicalID); err != nil {
-		return err
-	}
-	if _, err = exec.ExecuteInternal(ctx, "delete from mysql.stats_histograms where table_id = %?", physicalID); err != nil {
-		return err
-	}
-	if _, err = exec.ExecuteInternal(ctx, "delete from mysql.stats_buckets where table_id = %?", physicalID); err != nil {
-		return err
-	}
-	if _, err = exec.ExecuteInternal(ctx, "delete from mysql.stats_top_n where table_id = %?", physicalID); err != nil {
-		return err
-	}
-	if _, err = exec.ExecuteInternal(ctx, "delete from mysql.stats_feedback where table_id = %?", physicalID); err != nil {
-		return err
-	}
-	if _, err = exec.ExecuteInternal(ctx, "update mysql.stats_extended set version = %?, status = %? where table_id = %? and status in (%?, %?)", startTS, StatsStatusDeleted, physicalID, StatsStatusAnalyzed, StatsStatusInited); err != nil {
-		return err
+	for _, statsID := range statsIDs {
+		// We only update the version so that other tidb will know that this table is deleted.
+		if _, err = exec.ExecuteInternal(ctx, "update mysql.stats_meta set version = %? where table_id = %? ", startTS, statsID); err != nil {
+			return err
+		}
+		if _, err = exec.ExecuteInternal(ctx, "delete from mysql.stats_histograms where table_id = %?", statsID); err != nil {
+			return err
+		}
+		if _, err = exec.ExecuteInternal(ctx, "delete from mysql.stats_buckets where table_id = %?", statsID); err != nil {
+			return err
+		}
+		if _, err = exec.ExecuteInternal(ctx, "delete from mysql.stats_top_n where table_id = %?", statsID); err != nil {
+			return err
+		}
+		if _, err = exec.ExecuteInternal(ctx, "delete from mysql.stats_feedback where table_id = %?", statsID); err != nil {
+			return err
+		}
+		if _, err = exec.ExecuteInternal(ctx, "update mysql.stats_extended set version = %?, status = %? where table_id = %? and status in (%?, %?)", startTS, StatsStatusDeleted, statsID, StatsStatusAnalyzed, StatsStatusInited); err != nil {
+			return err
+		}
 	}
 	return nil
 }

statistics/handle/handle.go

@@ -47,6 +47,11 @@ import (
 	"go.uber.org/zap"
 )
 
+const (
+	// TiDBGlobalStats represents the global-stats for a partitioned table.
+	TiDBGlobalStats = "global"
+)
+
 // statsCache caches the tables in memory for Handle.
 type statsCache struct {
 	tables map[int64]*statistics.Table