*: enable tidb_enable_foreign_key variable default (#39677)

br/tests/br_foreign_key/run.sh

@@ -17,7 +17,6 @@
 set -eu
 DB="$TEST_NAME"
 
-run_sql "set @@global.tidb_enable_foreign_key=1;"
 run_sql "set @@global.foreign_key_checks=1;"
 run_sql "set @@foreign_key_checks=1;"
 run_sql "create schema $DB;"

cmd/explaintest/r/explain_foreign_key.result

@@ -1,4 +1,3 @@
-set @@global.tidb_enable_foreign_key=1;
 set @@foreign_key_checks=1;
 use test;
 drop table if exists t1,t2;
@@ -165,5 +164,4 @@ Delete	N/A	root		N/A
   └─TableReader(Probe)	3333.33	root		data:TableRangeScan
     └─TableRangeScan	3333.33	cop[tikv]	table:t_1	range:(0,+inf], keep order:true, stats:pseudo
 drop table if exists t_1,t_2,t_3,t_4;
-set @@global.tidb_enable_foreign_key=0;
 set @@foreign_key_checks=0;

cmd/explaintest/r/tpch.result

@@ -27,16 +27,13 @@ S_NATIONKEY   INTEGER NOT NULL,
 S_PHONE       CHAR(15) NOT NULL,
 S_ACCTBAL     DECIMAL(15,2) NOT NULL,
 S_COMMENT     VARCHAR(101) NOT NULL,
-PRIMARY KEY (S_SUPPKEY),
-CONSTRAINT FOREIGN KEY SUPPLIER_FK1 (S_NATIONKEY) references nation(N_NATIONKEY));
+PRIMARY KEY (S_SUPPKEY));
 CREATE TABLE IF NOT EXISTS partsupp ( PS_PARTKEY     INTEGER NOT NULL,
 PS_SUPPKEY     INTEGER NOT NULL,
 PS_AVAILQTY    INTEGER NOT NULL,
 PS_SUPPLYCOST  DECIMAL(15,2)  NOT NULL,
 PS_COMMENT     VARCHAR(199) NOT NULL,
-PRIMARY KEY (PS_PARTKEY,PS_SUPPKEY),
-CONSTRAINT FOREIGN KEY PARTSUPP_FK1 (PS_SUPPKEY) references supplier(S_SUPPKEY),
-CONSTRAINT FOREIGN KEY PARTSUPP_FK2 (PS_PARTKEY) references part(P_PARTKEY));
+PRIMARY KEY (PS_PARTKEY,PS_SUPPKEY));
 CREATE TABLE IF NOT EXISTS customer  ( C_CUSTKEY     INTEGER NOT NULL,
 C_NAME        VARCHAR(25) NOT NULL,
 C_ADDRESS     VARCHAR(40) NOT NULL,
@@ -45,8 +42,7 @@ C_PHONE       CHAR(15) NOT NULL,
 C_ACCTBAL     DECIMAL(15,2)   NOT NULL,
 C_MKTSEGMENT  CHAR(10) NOT NULL,
 C_COMMENT     VARCHAR(117) NOT NULL,
-PRIMARY KEY (C_CUSTKEY),
-CONSTRAINT FOREIGN KEY CUSTOMER_FK1 (C_NATIONKEY) references nation(N_NATIONKEY));
+PRIMARY KEY (C_CUSTKEY));
 CREATE TABLE IF NOT EXISTS orders  ( O_ORDERKEY       INTEGER NOT NULL,
 O_CUSTKEY        INTEGER NOT NULL,
 O_ORDERSTATUS    CHAR(1) NOT NULL,
@@ -56,8 +52,7 @@ O_ORDERPRIORITY  CHAR(15) NOT NULL,
 O_CLERK          CHAR(15) NOT NULL,
 O_SHIPPRIORITY   INTEGER NOT NULL,
 O_COMMENT        VARCHAR(79) NOT NULL,
-PRIMARY KEY (O_ORDERKEY),
-CONSTRAINT FOREIGN KEY ORDERS_FK1 (O_CUSTKEY) references customer(C_CUSTKEY));
+PRIMARY KEY (O_ORDERKEY));
 CREATE TABLE IF NOT EXISTS lineitem ( L_ORDERKEY    INTEGER NOT NULL,
 L_PARTKEY     INTEGER NOT NULL,
 L_SUPPKEY     INTEGER NOT NULL,
@@ -74,9 +69,7 @@ L_RECEIPTDATE DATE NOT NULL,
 L_SHIPINSTRUCT CHAR(25) NOT NULL,
 L_SHIPMODE     CHAR(10) NOT NULL,
 L_COMMENT      VARCHAR(44) NOT NULL,
-PRIMARY KEY (L_ORDERKEY,L_LINENUMBER),
-CONSTRAINT FOREIGN KEY LINEITEM_FK1 (L_ORDERKEY)  references orders(O_ORDERKEY),
-CONSTRAINT FOREIGN KEY LINEITEM_FK2 (L_PARTKEY,L_SUPPKEY) references partsupp(PS_PARTKEY, PS_SUPPKEY));
+PRIMARY KEY (L_ORDERKEY,L_LINENUMBER));
 load stats 's/tpch_stats/nation.json';
 load stats 's/tpch_stats/region.json';
 load stats 's/tpch_stats/part.json';

cmd/explaintest/t/explain_foreign_key.test

@@ -1,4 +1,3 @@
-set @@global.tidb_enable_foreign_key=1;
 set @@foreign_key_checks=1;
 use test;
 drop table if exists t1,t2;
@@ -43,5 +42,4 @@ set @@foreign_key_checks=0;
 explain format = 'brief' update t_1,t_2 set t_1.id=2,t_2.id=2 where t_1.id=t_2.id and t_1.id=1;
 explain format = 'brief' delete t_1,t_2 from t_1 join t_2 where t_1.id=t_2.id and t_1.id > 0;
 drop table if exists t_1,t_2,t_3,t_4;
-set @@global.tidb_enable_foreign_key=0;
 set @@foreign_key_checks=0;

cmd/explaintest/t/tpch.test

@@ -31,17 +31,14 @@ CREATE TABLE IF NOT EXISTS supplier  ( S_SUPPKEY     INTEGER NOT NULL,
                              S_PHONE       CHAR(15) NOT NULL,
                              S_ACCTBAL     DECIMAL(15,2) NOT NULL,
                              S_COMMENT     VARCHAR(101) NOT NULL,
-			     PRIMARY KEY (S_SUPPKEY),
-			     CONSTRAINT FOREIGN KEY SUPPLIER_FK1 (S_NATIONKEY) references nation(N_NATIONKEY));
+			     PRIMARY KEY (S_SUPPKEY));
 
 CREATE TABLE IF NOT EXISTS partsupp ( PS_PARTKEY     INTEGER NOT NULL,
                              PS_SUPPKEY     INTEGER NOT NULL,
                              PS_AVAILQTY    INTEGER NOT NULL,
                              PS_SUPPLYCOST  DECIMAL(15,2)  NOT NULL,
                              PS_COMMENT     VARCHAR(199) NOT NULL,
-			     PRIMARY KEY (PS_PARTKEY,PS_SUPPKEY),
-			     CONSTRAINT FOREIGN KEY PARTSUPP_FK1 (PS_SUPPKEY) references supplier(S_SUPPKEY),
-			     CONSTRAINT FOREIGN KEY PARTSUPP_FK2 (PS_PARTKEY) references part(P_PARTKEY));
+			     PRIMARY KEY (PS_PARTKEY,PS_SUPPKEY));
 
 CREATE TABLE IF NOT EXISTS customer  ( C_CUSTKEY     INTEGER NOT NULL,
                              C_NAME        VARCHAR(25) NOT NULL,
@@ -51,8 +48,7 @@ CREATE TABLE IF NOT EXISTS customer  ( C_CUSTKEY     INTEGER NOT NULL,
                              C_ACCTBAL     DECIMAL(15,2)   NOT NULL,
                              C_MKTSEGMENT  CHAR(10) NOT NULL,
                              C_COMMENT     VARCHAR(117) NOT NULL,
-			     PRIMARY KEY (C_CUSTKEY),
-			     CONSTRAINT FOREIGN KEY CUSTOMER_FK1 (C_NATIONKEY) references nation(N_NATIONKEY));
+			     PRIMARY KEY (C_CUSTKEY));
 
 CREATE TABLE IF NOT EXISTS orders  ( O_ORDERKEY       INTEGER NOT NULL,
                            O_CUSTKEY        INTEGER NOT NULL,
@@ -63,8 +59,7 @@ CREATE TABLE IF NOT EXISTS orders  ( O_ORDERKEY       INTEGER NOT NULL,
                            O_CLERK          CHAR(15) NOT NULL, 
                            O_SHIPPRIORITY   INTEGER NOT NULL,
                            O_COMMENT        VARCHAR(79) NOT NULL,
-			   PRIMARY KEY (O_ORDERKEY),
-			   CONSTRAINT FOREIGN KEY ORDERS_FK1 (O_CUSTKEY) references customer(C_CUSTKEY));
+			   PRIMARY KEY (O_ORDERKEY));
 
 CREATE TABLE IF NOT EXISTS lineitem ( L_ORDERKEY    INTEGER NOT NULL,
                              L_PARTKEY     INTEGER NOT NULL,
@@ -82,9 +77,7 @@ CREATE TABLE IF NOT EXISTS lineitem ( L_ORDERKEY    INTEGER NOT NULL,
                              L_SHIPINSTRUCT CHAR(25) NOT NULL,
                              L_SHIPMODE     CHAR(10) NOT NULL,
                              L_COMMENT      VARCHAR(44) NOT NULL,
-			     PRIMARY KEY (L_ORDERKEY,L_LINENUMBER),
-			     CONSTRAINT FOREIGN KEY LINEITEM_FK1 (L_ORDERKEY)  references orders(O_ORDERKEY),
-			     CONSTRAINT FOREIGN KEY LINEITEM_FK2 (L_PARTKEY,L_SUPPKEY) references partsupp(PS_PARTKEY, PS_SUPPKEY));
+			     PRIMARY KEY (L_ORDERKEY,L_LINENUMBER));
 -- load stats.
 load stats 's/tpch_stats/nation.json';
 load stats 's/tpch_stats/region.json';

ddl/cancel_test.go

@@ -149,7 +149,7 @@ var allTestCase = []testCancelJob{
 	{"alter table t modify column c11 char(10)", true, model.StateWriteReorganization, true, true, nil},
 	{"alter table t modify column c11 char(10)", false, model.StatePublic, false, true, nil},
 	// Add foreign key.
-	{"alter table t add constraint fk foreign key a(c1) references t_ref(c1)", true, model.StateNone, true, false, []string{"create table t_ref (c1 int, c2 int, c3 int, c11 tinyint);"}},
+	{"alter table t add constraint fk foreign key a(c1) references t_ref(c1)", true, model.StateNone, true, false, []string{"create table t_ref (c1 int key, c2 int, c3 int, c11 tinyint);"}},
 	{"alter table t add constraint fk foreign key a(c1) references t_ref(c1)", false, model.StatePublic, false, true, nil},
 	// Drop foreign key.
 	{"alter table t drop foreign key fk", true, model.StatePublic, true, false, nil},

ddl/db_table_test.go

@@ -51,7 +51,7 @@ func TestTableForeignKey(t *testing.T) {
 	store := testkit.CreateMockStore(t)
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
-	tk.MustExec("create table t1 (a int, b int);")
+	tk.MustExec("create table t1 (a int, b int, index(a), index(b));")
 	// test create table with foreign key.
 	failSQL := "create table t2 (c int, foreign key (a) references t1(a));"
 	tk.MustGetErrCode(failSQL, errno.ErrKeyColumnDoesNotExits)

ddl/foreign_key_test.go

@@ -28,6 +28,7 @@ import (
 	"github.com/pingcap/tidb/sessiontxn"
 	"github.com/pingcap/tidb/table"
 	"github.com/pingcap/tidb/testkit"
+	"github.com/pingcap/tidb/types"
 	"github.com/stretchr/testify/require"
 )
 
@@ -107,7 +108,17 @@ func TestForeignKey(t *testing.T) {
 	testCreateSchema(t, testkit.NewTestKit(t, store).Session(), dom.DDL(), dbInfo)
 	tblInfo, err := testTableInfo(store, "t", 3)
 	require.NoError(t, err)
-
+	tblInfo.Indices = append(tblInfo.Indices, &model.IndexInfo{
+		ID:    1,
+		Name:  model.NewCIStr("idx_fk"),
+		Table: model.NewCIStr("t"),
+		Columns: []*model.IndexColumn{{
+			Name:   model.NewCIStr("c1"),
+			Offset: 0,
+			Length: types.UnspecifiedLength,
+		}},
+		State: model.StatePublic,
+	})
 	testCreateTable(t, testkit.NewTestKit(t, store).Session(), d, dbInfo, tblInfo)
 
 	// fix data race

ddl/restart_test.go

@@ -141,7 +141,7 @@ func TestStat(t *testing.T) {
 		SchemaID:   dbInfo.ID,
 		Type:       model.ActionDropSchema,
 		BinlogInfo: &model.HistoryInfo{},
-		Args:       []interface{}{dbInfo.Name},
+		Args:       []interface{}{true},
 	}
 
 	done := make(chan error, 1)

ddl/serial_test.go

@@ -297,7 +297,7 @@ func TestCreateTableWithLikeAtTemporaryMode(t *testing.T) {
 
 	// Test foreign key.
 	tk.MustExec("drop table if exists test_foreign_key, t1")
-	tk.MustExec("create table t1 (a int, b int)")
+	tk.MustExec("create table t1 (a int, b int, index(b))")
 	tk.MustExec("create table test_foreign_key (c int,d int,foreign key (d) references t1 (b))")
 	defer tk.MustExec("drop table if exists test_foreign_key, t1")
 	tk.MustExec("create global temporary table test_foreign_key_temp like test_foreign_key on commit delete rows")
@@ -382,7 +382,7 @@ func TestCreateTableWithLikeAtTemporaryMode(t *testing.T) {
 	defer tk.MustExec("drop table if exists partition_table, tmp_partition_table")
 
 	tk.MustExec("drop table if exists foreign_key_table1, foreign_key_table2, foreign_key_tmp")
-	tk.MustExec("create table foreign_key_table1 (a int, b int)")
+	tk.MustExec("create table foreign_key_table1 (a int, b int, index(b))")
 	tk.MustExec("create table foreign_key_table2 (c int,d int,foreign key (d) references foreign_key_table1 (b))")
 	tk.MustExec("create temporary table foreign_key_tmp like foreign_key_table2")
 	is = sessiontxn.GetTxnManager(tk.Session()).GetTxnInfoSchema()

executor/fktest/foreign_key_test.go

@@ -1969,6 +1969,7 @@ func TestShowCreateTableWithForeignKey(t *testing.T) {
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
 
+	tk.MustExec("set @@global.tidb_enable_foreign_key=0")
 	tk.MustExec("create table t1 (id int key, leader int, leader2 int, index(leader), index(leader2), constraint fk foreign key (leader) references t1(id) ON DELETE CASCADE ON UPDATE SET NULL);")
 	tk.MustQuery("show create table t1").Check(testkit.Rows("t1 CREATE TABLE `t1` (\n" +
 		"  `id` int(11) NOT NULL,\n" +

executor/set_test.go

@@ -809,9 +809,9 @@ func TestSetVar(t *testing.T) {
 
 	// test variable 'foreign_key_checks'
 	// global scope
-	tk.MustQuery("select @@global.tidb_enable_foreign_key").Check(testkit.Rows("0")) // default value
-	tk.MustExec("set global tidb_enable_foreign_key = 1")
-	tk.MustQuery("select @@global.tidb_enable_foreign_key").Check(testkit.Rows("1"))
+	tk.MustQuery("select @@global.tidb_enable_foreign_key").Check(testkit.Rows("1")) // default value
+	tk.MustExec("set global tidb_enable_foreign_key = 0")
+	tk.MustQuery("select @@global.tidb_enable_foreign_key").Check(testkit.Rows("0"))
 
 	// test variable 'tidb_opt_force_inline_cte'
 	tk.MustQuery("select @@session.tidb_opt_force_inline_cte").Check(testkit.Rows("0")) // default value is 0

executor/showtest/show_test.go

@@ -331,7 +331,7 @@ func TestShowCreateTable(t *testing.T) {
 			"  `parent_id` int(11) NOT NULL,\n"+
 			"  PRIMARY KEY (`id`) /*T![clustered_index] CLUSTERED */,\n"+
 			"  KEY `par_ind` (`parent_id`),\n"+
-			"  CONSTRAINT `child_ibfk_1` FOREIGN KEY (`parent_id`) REFERENCES `test`.`parent` (`id`) /* FOREIGN KEY INVALID */\n"+
+			"  CONSTRAINT `child_ibfk_1` FOREIGN KEY (`parent_id`) REFERENCES `test`.`parent` (`id`)\n"+
 			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin",
 	))
 
@@ -345,7 +345,7 @@ func TestShowCreateTable(t *testing.T) {
 			"  `parent_id` int(11) NOT NULL,\n"+
 			"  PRIMARY KEY (`id`) /*T![clustered_index] CLUSTERED */,\n"+
 			"  KEY `par_ind` (`parent_id`),\n"+
-			"  CONSTRAINT `child_ibfk_1` FOREIGN KEY (`parent_id`) REFERENCES `test`.`parent` (`id`) ON DELETE RESTRICT ON UPDATE CASCADE /* FOREIGN KEY INVALID */\n"+
+			"  CONSTRAINT `child_ibfk_1` FOREIGN KEY (`parent_id`) REFERENCES `test`.`parent` (`id`) ON DELETE RESTRICT ON UPDATE CASCADE\n"+
 			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin",
 	))
 
@@ -358,7 +358,8 @@ func TestShowCreateTable(t *testing.T) {
 		"  `id` int(11) NOT NULL,\n" +
 		"  `b` int(11) DEFAULT NULL,\n" +
 		"  PRIMARY KEY (`id`) /*T![clustered_index] CLUSTERED */,\n" +
-		"  CONSTRAINT `fk` FOREIGN KEY (`b`) REFERENCES `test1`.`t1` (`id`) /* FOREIGN KEY INVALID */\n" +
+		"  KEY `fk` (`b`),\n" +
+		"  CONSTRAINT `fk` FOREIGN KEY (`b`) REFERENCES `test1`.`t1` (`id`)\n" +
 		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
 
 	// Test issue #20327

sessionctx/variable/sysvar.go

@@ -1257,7 +1257,7 @@ var defaultSysVars = []*SysVar{
 		}
 		return normalizedValue, ErrWrongValueForVar.GenWithStackByArgs(ForeignKeyChecks, originalValue)
 	}},
-	{Scope: ScopeGlobal, Name: TiDBEnableForeignKey, Value: BoolToOnOff(false), Type: TypeBool, SetGlobal: func(_ context.Context, s *SessionVars, val string) error {
+	{Scope: ScopeGlobal, Name: TiDBEnableForeignKey, Value: BoolToOnOff(true), Type: TypeBool, SetGlobal: func(_ context.Context, s *SessionVars, val string) error {
 		EnableForeignKey.Store(TiDBOptOn(val))
 		return nil
 	}, GetGlobal: func(_ context.Context, s *SessionVars) (string, error) {

sessionctx/variable/tidb_vars.go

@@ -1190,7 +1190,7 @@ var (
 	// DDLDiskQuota is the temporary variable for set disk quota for lightning
 	DDLDiskQuota = atomic.NewUint64(DefTiDBDDLDiskQuota)
 	// EnableForeignKey indicates whether to enable foreign key feature.
-	EnableForeignKey    = atomic.NewBool(false)
+	EnableForeignKey    = atomic.NewBool(true)
 	EnableRCReadCheckTS = atomic.NewBool(false)
 
 	// DefTiDBServerMemoryLimit indicates the default value of TiDBServerMemoryLimit(TotalMem * 80%).