importinto: forbid importing into TTL-enabled tables

pkg/executor/importer/BUILD.bazel

@@ -121,7 +121,7 @@ go_test(
     embed = [":importer"],
     flaky = True,
     race = "on",
-    shard_count = 44,
+    shard_count = 45,
     deps = [
         "//br/pkg/mock",
         "//br/pkg/streamhelper",

pkg/executor/importer/precheck.go

@@ -41,6 +41,7 @@ var GetEtcdClient = store.NewEtcdCli
 
 // CheckRequirements checks the requirements for IMPORT INTO.
 // we check the following things here:
+//   - target table should not have TTL enabled
 //   - when import from file
 //     1. there is no active job on the target table
 //     2. the total file size > 0
@@ -60,6 +61,18 @@ func (e *LoadDataController) CheckRequirementsBeforeInitDataFiles(ctx context.Co
 }
 
 func (e *LoadDataController) checkRequirements(ctx context.Context, se sessionctx.Context, checkTotalFileSize bool) error {
+	tableInfo := e.Plan.TableInfo
+	// Import table mode can prevent TTL from deleting data and causing a checksum
+	// mismatch. However, because TTL jobs run asynchronously, a job that races with the
+	// switch to import mode may still report a protected-table error. This precheck is
+	// also needed on versions that do not support table mode. Therefore, IMPORT INTO
+	// forbids importing into a table with TTL enabled. If later testing shows that IMPORT
+	// INTO can always switch table mode without an opt-out, TTL can check table mode before
+	// starting a job and this precheck can be removed.
+	if tableInfo.TTLInfo != nil && tableInfo.TTLInfo.Enable {
+		return exeerrors.ErrLoadDataPreCheckFailed.FastGenByArgs("target table has TTL enabled, please disable TTL before IMPORT INTO")
+	}
+
 	conn := se.GetSQLExecutor()
 	if e.DataSourceType == DataSourceTypeFile {
 		cnt, err := GetActiveJobCnt(ctx, conn, e.Plan.DBName, e.Plan.TableInfo.Name.L)

pkg/executor/importer/precheck_test.go

@@ -278,3 +278,47 @@ func TestCheckRequirements(t *testing.T) {
 	c.Plan.CloudStorageURI = fmt.Sprintf("s3://test-bucket/path?region=us-east-1&endpoint=%s&access-key=xxxxxx&secret-access-key=xxxxxx", ts.URL)
 	require.NoError(t, c.CheckRequirements(ctx, tk.Session()))
 }
+
+func TestCheckRequirementsTTL(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	ctx := util.WithInternalSourceType(context.Background(), kv.InternalImportInto)
+
+	tk.MustExec("create table test.t(id int primary key, created_at datetime) TTL = `created_at` + INTERVAL 1 DAY")
+	is := tk.Session().GetLatestInfoSchema().(infoschema.InfoSchema)
+	tableObj, err := is.TableByName(ctx, ast.NewCIStr("test"), ast.NewCIStr("t"))
+	require.NoError(t, err)
+	require.True(t, tableObj.Meta().TTLInfo.Enable)
+
+	c := &importer.LoadDataController{
+		Plan: &importer.Plan{
+			DBName:          "test",
+			DataSourceType:  importer.DataSourceTypeQuery,
+			DisablePrecheck: true,
+			TableInfo:       tableObj.Meta(),
+		},
+		Table: tableObj,
+	}
+	err = c.CheckRequirements(ctx, tk.Session())
+	require.ErrorIs(t, err, exeerrors.ErrLoadDataPreCheckFailed)
+	require.ErrorContains(t, err, "target table has TTL enabled, please disable TTL before IMPORT INTO")
+	err = c.CheckRequirementsBeforeInitDataFiles(ctx, tk.Session())
+	require.ErrorIs(t, err, exeerrors.ErrLoadDataPreCheckFailed)
+	require.ErrorContains(t, err, "target table has TTL enabled, please disable TTL before IMPORT INTO")
+
+	tk.MustExec("alter table test.t ttl_enable = 'OFF'")
+	is = tk.Session().GetLatestInfoSchema().(infoschema.InfoSchema)
+	tableObj, err = is.TableByName(ctx, ast.NewCIStr("test"), ast.NewCIStr("t"))
+	require.NoError(t, err)
+	c = &importer.LoadDataController{
+		Plan: &importer.Plan{
+			DBName:          "test",
+			DataSourceType:  importer.DataSourceTypeQuery,
+			DisablePrecheck: true,
+			TableInfo:       tableObj.Meta(),
+		},
+		Table: tableObj,
+	}
+	require.NoError(t, c.CheckRequirements(ctx, tk.Session()))
+	require.NoError(t, c.CheckRequirementsBeforeInitDataFiles(ctx, tk.Session()))
+}

tests/integrationtest/r/executor/import_into.result

@@ -197,3 +197,9 @@ create table cachetbl (id int);
 alter table cachetbl cache;
 import into cachetbl from '/file.csv';
 Error 1105 (HY000): IMPORT INTO does not support cached table
+drop table if exists import_into_ttl_precheck_source, import_into_ttl_precheck_target;
+create table import_into_ttl_precheck_source (id int primary key, created_at datetime);
+create table import_into_ttl_precheck_target (id int primary key, created_at datetime) TTL = `created_at` + INTERVAL 1 DAY;
+IMPORT INTO import_into_ttl_precheck_target FROM SELECT * FROM import_into_ttl_precheck_source WITH DISABLE_PRECHECK;
+Error 8173 (HY000): PreCheck failed: target table has TTL enabled, please disable TTL before IMPORT INTO
+drop table if exists import_into_ttl_precheck_source, import_into_ttl_precheck_target;

tests/integrationtest/t/executor/import_into.test

@@ -204,3 +204,11 @@ create table cachetbl (id int);
 alter table cachetbl cache;
 -- error 1105
 import into cachetbl from '/file.csv';
+
+# TestImportIntoTTLPrecheck
+drop table if exists import_into_ttl_precheck_source, import_into_ttl_precheck_target;
+create table import_into_ttl_precheck_source (id int primary key, created_at datetime);
+create table import_into_ttl_precheck_target (id int primary key, created_at datetime) TTL = `created_at` + INTERVAL 1 DAY;
+-- error 8173
+IMPORT INTO import_into_ttl_precheck_target FROM SELECT * FROM import_into_ttl_precheck_source WITH DISABLE_PRECHECK;
+drop table if exists import_into_ttl_precheck_source, import_into_ttl_precheck_target;