planner, infoschema : add columns about plan cache in 'performance_sc…

…hema.events_statements_summary_by_digest' (#16476) (#17493)

executor/adapter.go

@@ -977,5 +977,6 @@ func (a *ExecStmt) SummaryStmt(succ bool) {
 		StartTime:      sessVars.StartTime,
 		IsInternal:     sessVars.InRestrictedSQL,
 		Succeed:        succ,
+		PlanInCache:    sessVars.FoundInPlanCache,
 	})
 }

infoschema/perfschema/const.go

@@ -413,6 +413,8 @@ const tableEventsStatementsSummaryByDigest = "CREATE TABLE if not exists perform
 	"SUM_NO_GOOD_INDEX_USED bigint unsigned NOT NULL," +
 	"FIRST_SEEN timestamp(6) NOT NULL DEFAULT '0000-00-00 00:00:00.000000'," +
 	"LAST_SEEN timestamp(6) NOT NULL DEFAULT '0000-00-00 00:00:00.000000'," +
+	"PLAN_IN_CACHE bool NOT NULL," +
+	"PLAN_CACHE_HITS bigint unsigned NOT NULL," +
 	"QUANTILE_95 bigint unsigned NOT NULL," +
 	"QUANTILE_99 bigint unsigned NOT NULL," +
 	"QUANTILE_999 bigint unsigned NOT NULL," +

infoschema/tables.go

@@ -1194,6 +1194,8 @@ var tableStatementsSummaryCols = []columnInfo{
 	{name: "AVG_AFFECTED_ROWS", tp: mysql.TypeDouble, size: 22, flag: mysql.NotNullFlag | mysql.UnsignedFlag, comment: "Average number of rows affected"},
 	{name: "FIRST_SEEN", tp: mysql.TypeTimestamp, size: 26, flag: mysql.NotNullFlag, comment: "The time these statements are seen for the first time"},
 	{name: "LAST_SEEN", tp: mysql.TypeTimestamp, size: 26, flag: mysql.NotNullFlag, comment: "The time these statements are seen for the last time"},
+	{name: "PLAN_IN_CACHE", tp: mysql.TypeTiny, size: 1, flag: mysql.NotNullFlag, comment: "Whether the last statement hit plan cache"},
+	{name: "PLAN_CACHE_HITS", tp: mysql.TypeLonglong, size: 20, flag: mysql.NotNullFlag, comment: "The number of times these statements hit plan cache"},
 	{name: "QUERY_SAMPLE_TEXT", tp: mysql.TypeBlob, size: types.UnspecifiedLength, comment: "Sampled original statement"},
 	{name: "PREV_SAMPLE_TEXT", tp: mysql.TypeBlob, size: types.UnspecifiedLength, comment: "The previous statement before commit"},
 	{name: "PLAN_DIGEST", tp: mysql.TypeVarchar, size: 64, comment: "Digest of its execution plan"},

infoschema/tables_test.go

@@ -16,6 +16,7 @@ package infoschema_test
 import (
 	"crypto/tls"
 	"fmt"
+	"math"
 	"net"
 	"net/http/httptest"
 	"os"
@@ -36,11 +37,13 @@ import (
 	"github.com/pingcap/tidb/infoschema"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/meta/autoid"
+	plannercore "github.com/pingcap/tidb/planner/core"
 	"github.com/pingcap/tidb/server"
 	"github.com/pingcap/tidb/session"
 	"github.com/pingcap/tidb/store/helper"
 	"github.com/pingcap/tidb/store/mockstore"
 	"github.com/pingcap/tidb/util"
+	"github.com/pingcap/tidb/util/kvcache"
 	"github.com/pingcap/tidb/util/pdapi"
 	"github.com/pingcap/tidb/util/set"
 	"github.com/pingcap/tidb/util/testkit"
@@ -84,6 +87,18 @@ func (s *testTableSuiteBase) newTestKitWithRoot(c *C) *testkit.TestKit {
 	return tk
 }
 
+func (s *testTableSuiteBase) newTestKitWithPlanCache(c *C) *testkit.TestKit {
+	tk := testkit.NewTestKit(c, s.store)
+	var err error
+	tk.Se, err = session.CreateSession4TestWithOpt(s.store, &session.Opt{
+		PreparedPlanCache: kvcache.NewSimpleLRUCache(100, 0.1, math.MaxUint64),
+	})
+	c.Assert(err, IsNil)
+	tk.GetConnectionID()
+	c.Assert(tk.Se.Auth(&auth.UserIdentity{Username: "root", Hostname: "%"}, nil, nil), IsTrue)
+	return tk
+}
+
 type testClusterTableSuite struct {
 	*testTableSuiteBase
 	rpcserver  *grpc.Server
@@ -1231,3 +1246,29 @@ func (s *testTableSuite) TestStmtSummaryPreparedStatements(c *C) {
 		from information_schema.statements_summary
 		where digest_text like "select ?"`).Check(testkit.Rows("1"))
 }
+
+func (s *testTableSuite) TestPerformanceSchemaforPlanCache(c *C) {
+	orgEnable := plannercore.PreparedPlanCacheEnabled()
+	defer func() {
+		plannercore.SetPreparedPlanCache(orgEnable)
+	}()
+	plannercore.SetPreparedPlanCache(true)
+
+	tk := s.newTestKitWithPlanCache(c)
+
+	// Clear summaries.
+	tk.MustExec("set global tidb_enable_stmt_summary = 0")
+	tk.MustExec("set global tidb_enable_stmt_summary = 1")
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t(a int)")
+	tk.MustExec("prepare stmt from 'select * from t'")
+	tk.MustExec("execute stmt")
+	tk.MustQuery("select plan_cache_hits, plan_in_cache from information_schema.statements_summary where digest_text='select * from t'").Check(
+		testkit.Rows("0 0"))
+	tk.MustExec("execute stmt")
+	tk.MustExec("execute stmt")
+	tk.MustExec("execute stmt")
+	tk.MustQuery("select plan_cache_hits, plan_in_cache from information_schema.statements_summary where digest_text='select * from t'").Check(
+		testkit.Rows("3 1"))
+}

util/stmtsummary/statement_summary.go

@@ -168,6 +168,9 @@ type stmtSummaryByDigestElement struct {
 	firstSeen time.Time
 	// The last time this type of SQL executes.
 	lastSeen time.Time
+	// plan cache
+	planInCache   bool
+	planCacheHits int64
 }
 
 // StmtExecInfo records execution information of each statement.
@@ -192,6 +195,7 @@ type StmtExecInfo struct {
 	StartTime      time.Time
 	IsInternal     bool
 	Succeed        bool
+	PlanInCache    bool
 }
 
 // newStmtSummaryByDigestMap creates an empty stmtSummaryByDigestMap.
@@ -568,13 +572,15 @@ func newStmtSummaryByDigestElement(sei *StmtExecInfo, beginTime int64, intervalS
 		// PrevSQL is already truncated to cfg.Log.QueryLogMaxLen.
 		prevSQL: sei.PrevSQL,
 		// samplePlan needs to be decoded so it can't be truncated.
-		samplePlan:   sei.PlanGenerator(),
-		indexNames:   sei.StmtCtx.IndexNames,
-		minLatency:   sei.TotalLatency,
-		firstSeen:    sei.StartTime,
-		lastSeen:     sei.StartTime,
-		backoffTypes: make(map[fmt.Stringer]int),
-		authUsers:    make(map[string]struct{}),
+		samplePlan:    sei.PlanGenerator(),
+		indexNames:    sei.StmtCtx.IndexNames,
+		minLatency:    sei.TotalLatency,
+		firstSeen:     sei.StartTime,
+		lastSeen:      sei.StartTime,
+		backoffTypes:  make(map[fmt.Stringer]int),
+		authUsers:     make(map[string]struct{}),
+		planInCache:   false,
+		planCacheHits: 0,
 	}
 	ssElement.add(sei, intervalSeconds)
 	return ssElement
@@ -721,6 +727,12 @@ func (ssElement *stmtSummaryByDigestElement) add(sei *StmtExecInfo, intervalSeco
 		commitDetails.Mu.Unlock()
 	}
 
+	//plan cache
+	if sei.PlanInCache {
+		ssElement.planInCache = true
+		ssElement.planCacheHits += 1
+	}
+
 	// other
 	ssElement.sumAffectedRows += sei.StmtCtx.AffectedRows()
 	ssElement.sumMem += sei.MemMax
@@ -815,6 +827,8 @@ func (ssElement *stmtSummaryByDigestElement) toDatum(ssbd *stmtSummaryByDigest)
 		avgFloat(int64(ssElement.sumAffectedRows), ssElement.execCount),
 		types.NewTime(types.FromGoTime(ssElement.firstSeen), mysql.TypeTimestamp, 0),
 		types.NewTime(types.FromGoTime(ssElement.lastSeen), mysql.TypeTimestamp, 0),
+		ssElement.planInCache,
+		ssElement.planCacheHits,
 		ssElement.sampleSQL,
 		ssElement.prevSQL,
 		ssbd.planDigest,

util/stmtsummary/statement_summary_test.go

@@ -606,7 +606,7 @@ func (s *testStmtSummarySuite) TestToDatum(c *C) {
 		stmtExecInfo1.ExecDetail.CommitDetail.PrewriteRegionNum, stmtExecInfo1.ExecDetail.CommitDetail.PrewriteRegionNum,
 		stmtExecInfo1.ExecDetail.CommitDetail.TxnRetry, stmtExecInfo1.ExecDetail.CommitDetail.TxnRetry, 1,
 		"txnLock:1", stmtExecInfo1.MemMax, stmtExecInfo1.MemMax, stmtExecInfo1.StmtCtx.AffectedRows(),
-		t, t, stmtExecInfo1.OriginalSQL, stmtExecInfo1.PrevSQL, "plan_digest", ""}
+		t, t, 0, 0, stmtExecInfo1.OriginalSQL, stmtExecInfo1.PrevSQL, "plan_digest", ""}
 	match(c, datums[0], expectedDatum...)
 
 	datums = s.ssMap.ToHistoryDatum(nil, true)

util/testkit/testkit.go

@@ -129,14 +129,21 @@ func NewTestKitWithInit(c *check.C, store kv.Storage) *TestKit {
 
 var connectionID uint64
 
+// GetConnectionID get the connection ID for tk.Se
+func (tk *TestKit) GetConnectionID() {
+	if tk.Se != nil {
+		id := atomic.AddUint64(&connectionID, 1)
+		tk.Se.SetConnectionID(id)
+	}
+}
+
 // Exec executes a sql statement.
 func (tk *TestKit) Exec(sql string, args ...interface{}) (sqlexec.RecordSet, error) {
 	var err error
 	if tk.Se == nil {
 		tk.Se, err = session.CreateSession4Test(tk.store)
 		tk.c.Assert(err, check.IsNil)
-		id := atomic.AddUint64(&connectionID, 1)
-		tk.Se.SetConnectionID(id)
+		tk.GetConnectionID()
 	}
 	ctx := context.Background()
 	if len(args) == 0 {