ttl: fix a wrong ttl's job schedule for TTL table upgraded from 6.5 (#56540) (#56591)

close #56539

Author: ti-chi-bot

executor/show.go

@@ -1309,7 +1309,7 @@ func ConstructResultOfShowCreateTable(ctx sessionctx.Context, tableInfo *model.T
 			restoreCtx.WriteKeyWord("TTL_JOB_INTERVAL")
 			restoreCtx.WritePlain("=")
 			if len(tableInfo.TTLInfo.JobInterval) == 0 {
-				restoreCtx.WriteString(model.DefaultJobInterval.String())
+				restoreCtx.WriteString(model.DefaultJobIntervalStr)
 			} else {
 				restoreCtx.WriteString(tableInfo.TTLInfo.JobInterval)
 			}

parser/model/BUILD.bazel

@@ -30,9 +30,10 @@ go_test(
     ],
     embed = [":model"],
     flaky = True,
-    shard_count = 20,
+    shard_count = 21,
     deps = [
         "//parser/charset",
+        "//parser/duration",
         "//parser/mysql",
         "//parser/terror",
         "//parser/types",

parser/model/model.go

@@ -1757,6 +1757,9 @@ func (p *PolicyInfo) Clone() *PolicyInfo {
 // DefaultJobInterval sets the default interval between TTL jobs
 const DefaultJobInterval = time.Hour
 
+// DefaultJobIntervalStr is the string representation of DefaultJobInterval
+const DefaultJobIntervalStr = "1h"
+
 // TTLInfo records the TTL config
 type TTLInfo struct {
 	ColumnName      CIStr  `json:"column"`

parser/model/model_test.go

@@ -20,6 +20,7 @@ import (
 	"time"
 
 	"github.com/pingcap/tidb/parser/charset"
+	"github.com/pingcap/tidb/parser/duration"
 	"github.com/pingcap/tidb/parser/mysql"
 	"github.com/pingcap/tidb/parser/types"
 	"github.com/stretchr/testify/require"
@@ -818,3 +819,10 @@ func TestTTLJobInterval(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, time.Hour*200, interval)
 }
+
+func TestTTLDefaultJobInterval(t *testing.T) {
+	// test const `DefaultJobIntervalStr` and `DefaultJobInterval` are consistent.
+	d, err := duration.ParseDuration(DefaultJobIntervalStr)
+	require.NoError(t, err)
+	require.Equal(t, DefaultJobInterval, d)
+}