Merge branch 'master' into fix-cast-str-to-time

executor/builder.go

@@ -2435,6 +2435,15 @@ func (b *executorBuilder) buildAnalyzeSamplingPushdown(task plannercore.AnalyzeC
 }
 
 // getAdjustedSampleRate calculate the sample rate by the table size. If we cannot get the table size. We use the 0.001 as the default sample rate.
+// From the paper "Random sampling for histogram construction: how much is enough?"'s Corollary 1 to Theorem 5,
+// for a table size n, histogram size k, maximum relative error in bin size f, and error probability gamma,
+// the minimum random sample size is
+//         r = 4 * k * ln(2*n/gamma) / f^2
+// If we take f = 0.5, gamma = 0.01, n =1e6, we would got r = 305.82* k.
+// Since the there's log function over the table size n, the r grows slowly when the n increases.
+// If we take n = 1e12, a 300*k sample still gives <= 0.66 bin size error with probability 0.99.
+// So if we don't consider the top-n values, we can keep the sample size at 300*256.
+// But we may take some top-n before building the histogram, so we increase the sample a little.
 func (b *executorBuilder) getAdjustedSampleRate(sctx sessionctx.Context, task plannercore.AnalyzeColumnsTask) float64 {
 	statsHandle := domain.GetDomain(sctx).StatsHandle()
 	defaultRate := 0.001

expression/builtin_time.go

@@ -4129,9 +4129,13 @@ func (c *unixTimestampFunctionClass) getFunction(ctx sessionctx.Context, args []
 
 // goTimeToMysqlUnixTimestamp converts go time into MySQL's Unix timestamp.
 // MySQL's Unix timestamp ranges in int32. Values out of range should be rewritten to 0.
+// https://dev.mysql.com/doc/refman/8.0/en/date-and-time-functions.html#function_unix-timestamp
 func goTimeToMysqlUnixTimestamp(t time.Time, decimal int) (*types.MyDecimal, error) {
 	nanoSeconds := t.UnixNano()
-	if nanoSeconds < 0 || (nanoSeconds/1e3) >= (math.MaxInt32+1)*1e6 {
+	// Prior to MySQL 8.0.28, the valid range of argument values is the same as for the TIMESTAMP data type:
+	// '1970-01-01 00:00:01.000000' UTC to '2038-01-19 03:14:07.999999' UTC.
+	// This is also the case in MySQL 8.0.28 and later for 32-bit platforms.
+	if nanoSeconds < 1e9 || (nanoSeconds/1e3) >= (math.MaxInt32+1)*1e6 {
 		return new(types.MyDecimal), nil
 	}
 	dec := new(types.MyDecimal)

expression/integration_serial_test.go

@@ -2387,6 +2387,12 @@ func TestTimeBuiltin(t *testing.T) {
 
 	// for unix_timestamp
 	tk.MustExec("SET time_zone = '+00:00';")
+	tk.MustQuery("SELECT UNIX_TIMESTAMP('1970-01-01 00:00:00.000001');").Check(testkit.Rows("0.000000"))
+	tk.MustQuery("SELECT UNIX_TIMESTAMP('1970-01-01 00:00:00.999999');").Check(testkit.Rows("0.000000"))
+	tk.MustQuery("SELECT UNIX_TIMESTAMP('1970-01-01 00:00:01.000000');").Check(testkit.Rows("1.000000"))
+	tk.MustQuery("SELECT UNIX_TIMESTAMP('2038-01-19 03:14:07.999999');").Check(testkit.Rows("2147483647.999999"))
+	tk.MustQuery("SELECT UNIX_TIMESTAMP('2038-01-19 03:14:08.000000');").Check(testkit.Rows("0.000000"))
+
 	result = tk.MustQuery("SELECT UNIX_TIMESTAMP(151113);")
 	result.Check(testkit.Rows("1447372800"))
 	result = tk.MustQuery("SELECT UNIX_TIMESTAMP(20151113);")

tests/globalkilltest/global_kill_test.go

@@ -49,7 +49,10 @@ var (
 
 	pdClientPath = flag.String("pd", "127.0.0.1:2379", "pd client path")
 
-	lostConnectionToPDTimeout       = flag.Int("conn_lost", 5, "lost connection to PD timeout, should be the same as TiDB ldflag <ldflagLostConnectionToPDTimeout>")
+	// nolint: unused, deadcode
+	lostConnectionToPDTimeout = flag.Int("conn_lost", 5, "lost connection to PD timeout, should be the same as TiDB ldflag <ldflagLostConnectionToPDTimeout>")
+
+	// nolint: unused, deadcode
 	timeToCheckPDConnectionRestored = flag.Int("conn_restored", 1, "time to check PD connection restored, should be the same as TiDB ldflag <ldflagServerIDTimeToCheckPDConnectionRestored>")
 )
 
@@ -64,7 +67,7 @@ type GlobalKillSuite struct {
 	pdCli *clientv3.Client
 	pdErr error
 
-	clusterId string
+	clusterID string
 	pdProc    *exec.Cmd
 	tikvProc  *exec.Cmd
 }
@@ -74,7 +77,7 @@ func createGloabalKillSuite(t *testing.T) (s *GlobalKillSuite, clean func()) {
 	err := logutil.InitLogger(&logutil.LogConfig{Config: log.Config{Level: *logLevel}})
 	require.NoError(t, err)
 
-	s.clusterId = time.Now().Format(time.RFC3339Nano)
+	s.clusterID = time.Now().Format(time.RFC3339Nano)
 	err = s.startCluster()
 	require.NoError(t, err)
 	s.pdCli, s.pdErr = s.connectPD()
@@ -157,12 +160,12 @@ func (s *GlobalKillSuite) startPD(dataDir string) (err error) {
 }
 
 func (s *GlobalKillSuite) startCluster() (err error) {
-	err = s.startPD(s.clusterId)
+	err = s.startPD(s.clusterID)
 	if err != nil {
 		return
 	}
 
-	err = s.startTiKV(s.clusterId)
+	err = s.startTiKV(s.clusterID)
 	if err != nil {
 		return
 	}