diff --git a/pkg/admin/router/clusters.go b/pkg/admin/router/clusters.go
index da8f7051f..80a58b659 100644
--- a/pkg/admin/router/clusters.go
+++ b/pkg/admin/router/clusters.go
@@ -83,7 +83,7 @@ func CreateCluster(c *gin.Context) error {
 		return exception.Wrap(exception.CodeInvalidParams, err)
 	}
 
-	//TODO how to get cluster name?
+	// TODO how to get cluster name?
 	err := service.UpsertCluster(context.Background(), tenant, "", cluster)
 	if err != nil {
 		return err
diff --git a/pkg/admin/router/db_groups.go b/pkg/admin/router/db_groups.go
index 590763c05..1fbb99d1e 100644
--- a/pkg/admin/router/db_groups.go
+++ b/pkg/admin/router/db_groups.go
@@ -62,7 +62,7 @@ func CreateGroup(c *gin.Context) error {
 func ListGroups(c *gin.Context) error {
 	service := admin.GetService(c)
 	tenantName := c.Param("tenant")
-	//cluster := c.Param("cluster")
+	// cluster := c.Param("cluster")
 	clusters, err := service.ListClusters(context.Background(), tenantName)
 	if err != nil {
 		return err
diff --git a/pkg/admin/router/misc.go b/pkg/admin/router/misc.go
index 22fb3a280..4839626c3 100644
--- a/pkg/admin/router/misc.go
+++ b/pkg/admin/router/misc.go
@@ -26,8 +26,10 @@ import (
 	"github.com/pkg/errors"
 )
 
-var _tenantNameRegexp *regexp.Regexp
-var _tenantNameRegexpOnce sync.Once
+var (
+	_tenantNameRegexp     *regexp.Regexp
+	_tenantNameRegexpOnce sync.Once
+)
 
 func validateTenantName(name string) error {
 	_tenantNameRegexpOnce.Do(func() {
diff --git a/pkg/boot/boot.go b/pkg/boot/boot.go
index 6f69a0e13..0fac27bee 100644
--- a/pkg/boot/boot.go
+++ b/pkg/boot/boot.go
@@ -202,7 +202,7 @@ func buildNamespace(ctx context.Context, tenant string, provider Discovery, clus
 		return nil, err
 	}
 
-	var initCmds = []namespace.Command{
+	initCmds := []namespace.Command{
 		namespace.UpdateSlowLogger(provider.GetOptions().SlowLogPath),
 		namespace.UpdateParameters(cluster.Parameters),
 		namespace.UpdateSlowThreshold(),
diff --git a/pkg/boot/discovery.go b/pkg/boot/discovery.go
index fbde9772c..825f6377b 100644
--- a/pkg/boot/discovery.go
+++ b/pkg/boot/discovery.go
@@ -102,57 +102,57 @@ func (fp *discovery) UpsertTenant(ctx context.Context, tenant string, body *Tena
 }
 
 func (fp *discovery) RemoveTenant(ctx context.Context, tenant string) error {
-	//TODO implement me
+	// TODO implement me
 	panic("implement me")
 }
 
 func (fp *discovery) UpsertCluster(ctx context.Context, tenant, cluster string, body *ClusterBody) error {
-	//TODO implement me
+	// TODO implement me
 	panic("implement me")
 }
 
 func (fp *discovery) RemoveCluster(ctx context.Context, tenant, cluster string) error {
-	//TODO implement me
+	// TODO implement me
 	panic("implement me")
 }
 
 func (fp *discovery) UpsertNode(ctx context.Context, tenant, node string, body *NodeBody) error {
-	//TODO implement me
+	// TODO implement me
 	panic("implement me")
 }
 
 func (fp *discovery) RemoveNode(ctx context.Context, tenant, node string) error {
-	//TODO implement me
+	// TODO implement me
 	panic("implement me")
 }
 
 func (fp *discovery) UpsertGroup(ctx context.Context, tenant, cluster, group string, body *GroupBody) error {
-	//TODO implement me
+	// TODO implement me
 	panic("implement me")
 }
 
 func (fp *discovery) RemoveGroup(ctx context.Context, tenant, cluster, group string) error {
-	//TODO implement me
+	// TODO implement me
 	panic("implement me")
 }
 
 func (fp *discovery) BindNode(ctx context.Context, tenant, cluster, group, node string) error {
-	//TODO implement me
+	// TODO implement me
 	panic("implement me")
 }
 
 func (fp *discovery) UnbindNode(ctx context.Context, tenant, cluster, group, node string) error {
-	//TODO implement me
+	// TODO implement me
 	panic("implement me")
 }
 
 func (fp *discovery) UpsertTable(ctx context.Context, tenant, cluster, table string, body *TableBody) error {
-	//TODO implement me
+	// TODO implement me
 	panic("implement me")
 }
 
 func (fp *discovery) RemoveTable(ctx context.Context, tenant, cluster, table string) error {
-	//TODO implement me
+	// TODO implement me
 	panic("implement me")
 }
 
@@ -263,7 +263,6 @@ func (fp *discovery) GetCluster(ctx context.Context, tenant, cluster string) (*C
 }
 
 func (fp *discovery) ListTenants(ctx context.Context) ([]string, error) {
-
 	return fp.tenantOp.ListTenants(), nil
 }
 
@@ -349,7 +348,6 @@ func (fp *discovery) ListGroups(ctx context.Context, tenant, cluster string) ([]
 }
 
 func (fp *discovery) ListNodes(ctx context.Context, tenant, cluster, group string) ([]string, error) {
-
 	bingo, ok := fp.loadGroup(tenant, cluster, group)
 	if !ok {
 		return nil, nil
@@ -393,7 +391,6 @@ func (fp *discovery) ListTables(ctx context.Context, tenant, cluster string) ([]
 }
 
 func (fp *discovery) GetNode(ctx context.Context, tenant, cluster, group, node string) (*config.Node, error) {
-
 	op, ok := fp.centers[tenant]
 	if !ok {
 		return nil, ErrorNoTenant
diff --git a/pkg/config/api.go b/pkg/config/api.go
index 2e98774f8..e68b86dc7 100644
--- a/pkg/config/api.go
+++ b/pkg/config/api.go
@@ -101,7 +101,7 @@ type (
 		Options   map[string]interface{} `yaml:"options"`
 	}
 
-	//TenantOperator actions specific to tenant spaces
+	// TenantOperator actions specific to tenant spaces
 	TenantOperator interface {
 		io.Closer
 
diff --git a/pkg/config/config.go b/pkg/config/config.go
index 2be559bdf..855e99c35 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -57,7 +57,6 @@ type PathInfo struct {
 }
 
 func NewPathInfo(tenant string) *PathInfo {
-
 	p := &PathInfo{}
 
 	p.DefaultTenantBaseConfigPath = PathKey(filepath.Join(string(DefaultRootPath), fmt.Sprintf("tenants/%s", tenant)))
@@ -260,7 +259,7 @@ func (tp *tenantOperate) CreateTenant(name string) error {
 		return errors.Wrap(err, "create tenant name")
 	}
 
-	//need to insert the relevant configuration data under the relevant tenant
+	// need to insert the relevant configuration data under the relevant tenant
 	tenantPathInfo := NewPathInfo(name)
 	for i := range tenantPathInfo.ConfigKeyMapping {
 		if err := tp.op.Save(i, []byte("")); err != nil {
@@ -390,7 +389,6 @@ type center struct {
 }
 
 func NewCenter(tenant string, op StoreOperator) Center {
-
 	p := NewPathInfo(tenant)
 
 	holders := map[PathKey]*atomic.Value{}
@@ -544,7 +542,6 @@ func (c *center) PersistContext(ctx context.Context) error {
 }
 
 func (c *center) doPersist(ctx context.Context, conf *Tenant) error {
-
 	configJson, err := json.Marshal(conf)
 	if err != nil {
 		return errors.Wrap(err, "config json.marshal failed")
@@ -564,9 +561,8 @@ func (c *center) doPersist(ctx context.Context, conf *Tenant) error {
 	return nil
 }
 
-//Subscribe
+// Subscribe
 func (c *center) Subscribe(ctx context.Context, et EventType, f callback) context.CancelFunc {
-
 	return c.observers.add(et, f)
 }
 
diff --git a/pkg/config/default.go b/pkg/config/default.go
index 9e84f6520..5098ed9f6 100644
--- a/pkg/config/default.go
+++ b/pkg/config/default.go
@@ -26,9 +26,7 @@ import (
 	"github.com/arana-db/arana/pkg/util/log"
 )
 
-var (
-	ErrorNoStoreOperate = errors.New("no store operate")
-)
+var ErrorNoStoreOperate = errors.New("no store operate")
 
 func GetStoreOperate() StoreOperator {
 	return storeOperate
diff --git a/pkg/config/diff.go b/pkg/config/diff.go
index bbc3d687c..375a4f96b 100644
--- a/pkg/config/diff.go
+++ b/pkg/config/diff.go
@@ -171,7 +171,6 @@ func (c Clusters) Diff(old Clusters) *ClustersEvent {
 }
 
 func (d *DataSourceCluster) Diff(old *DataSourceCluster) *ClusterEvent {
-
 	ret := &ClusterEvent{
 		Name:        d.Name,
 		Type:        d.Type,
diff --git a/pkg/config/equals.go b/pkg/config/equals.go
index 6a12efd43..6a11858fa 100644
--- a/pkg/config/equals.go
+++ b/pkg/config/equals.go
@@ -23,7 +23,6 @@ import (
 )
 
 func (u *User) Equals(o *User) bool {
-
 	return u.Username == o.Username && u.Password == o.Password
 }
 
diff --git a/pkg/config/etcd/etcd.go b/pkg/config/etcd/etcd.go
index 26fd8810b..ca27f023b 100644
--- a/pkg/config/etcd/etcd.go
+++ b/pkg/config/etcd/etcd.go
@@ -38,9 +38,7 @@ import (
 	"github.com/arana-db/arana/pkg/util/log"
 )
 
-var (
-	PluginName = "etcd"
-)
+var PluginName = "etcd"
 
 func init() {
 	config.Register(&storeOperate{
@@ -67,7 +65,6 @@ func (c *storeOperate) Init(options map[string]interface{}) error {
 		DialTimeout: 10 * time.Second,
 		DialOptions: []grpc.DialOption{grpc.WithBlock()},
 	})
-
 	if err != nil {
 		log.Errorf("failed to initialize etcd client error: %s", err.Error())
 		return err
@@ -142,7 +139,6 @@ func (w *etcdWatcher) run(ctx context.Context) {
 }
 
 func (c *storeOperate) Watch(key config.PathKey) (<-chan []byte, error) {
-
 	c.lock.Lock()
 	defer c.lock.Unlock()
 
diff --git a/pkg/config/file/file.go b/pkg/config/file/file.go
index c644cd755..c6d7e0014 100644
--- a/pkg/config/file/file.go
+++ b/pkg/config/file/file.go
@@ -180,7 +180,7 @@ func (s *storeOperate) Save(key config.PathKey, val []byte) error {
 	return nil
 }
 
-//Get
+// Get
 func (s *storeOperate) Get(key config.PathKey) ([]byte, error) {
 	s.lock.RLock()
 	defer s.lock.RUnlock()
@@ -201,7 +201,6 @@ func (s *storeOperate) Name() string {
 }
 
 func (s *storeOperate) Close() error {
-
 	for i := range s.cancels {
 		s.cancels[i]()
 	}
@@ -209,7 +208,7 @@ func (s *storeOperate) Close() error {
 	return nil
 }
 
-//readFromFile
+// readFromFile
 func (s *storeOperate) readFromFile(path string, cfg *config.Configuration) error {
 	var (
 		f   *os.File
@@ -257,9 +256,8 @@ func formatPath(path string) (string, error) {
 	return path, nil
 }
 
-//watchFileChange
+// watchFileChange
 func (s *storeOperate) watchFileChange(ctx context.Context, path string) {
-
 	refreshT := time.NewTicker(30 * time.Second)
 
 	oldStat, err := os.Stat(path)
@@ -292,5 +290,4 @@ func (s *storeOperate) watchFileChange(ctx context.Context, path string) {
 
 		}
 	}
-
 }
diff --git a/pkg/config/nacos/nacos.go b/pkg/config/nacos/nacos.go
index aa243d2a0..baaa89af4 100644
--- a/pkg/config/nacos/nacos.go
+++ b/pkg/config/nacos/nacos.go
@@ -180,7 +180,6 @@ func (s *storeOperate) Get(key config.PathKey) ([]byte, error) {
 		DataId: buildNacosDataId(string(key)),
 		Group:  s.groupName,
 	})
-
 	if err != nil {
 		return nil, err
 	}
diff --git a/pkg/config/nacos/nacos_test.go b/pkg/config/nacos/nacos_test.go
index 6676a7cd4..243197fd4 100644
--- a/pkg/config/nacos/nacos_test.go
+++ b/pkg/config/nacos/nacos_test.go
@@ -238,5 +238,4 @@ func Test_storeOpertae(t *testing.T) {
 	err = operate.Save(mockPath[newCfg.Data.Tenants[0].Name].DefaultConfigDataShadowRulePath, []byte(" "))
 
 	assert.NoError(t, err, "blank string should be success")
-
 }
diff --git a/pkg/executor/redirect.go b/pkg/executor/redirect.go
index c7ff4a068..c0b88a94a 100644
--- a/pkg/executor/redirect.go
+++ b/pkg/executor/redirect.go
@@ -120,7 +120,6 @@ func (executor *RedirectExecutor) ExecuteFieldList(ctx *proto.Context) ([]proto.
 }
 
 func (executor *RedirectExecutor) ExecutorComQuery(ctx *proto.Context) (proto.Result, uint16, error) {
-
 	var (
 		schemaless bool // true if schema is not specified
 		err        error
diff --git a/pkg/proto/runtime.go b/pkg/proto/runtime.go
index 58d387c43..b39b61a72 100644
--- a/pkg/proto/runtime.go
+++ b/pkg/proto/runtime.go
@@ -30,10 +30,17 @@ const (
 )
 
 type (
+	// VersionSupport provides the version string.
+	VersionSupport interface {
+		// Version returns the version.
+		Version(ctx context.Context) (string, error)
+	}
+
 	// VConn represents a virtual connection which can be used to query/exec from a db.
 	VConn interface {
 		// Query requests a query command.
 		Query(ctx context.Context, db string, query string, args ...interface{}) (Result, error)
+
 		// Exec requests a exec command
 		Exec(ctx context.Context, db string, query string, args ...interface{}) (Result, error)
 	}
@@ -73,24 +80,36 @@ type (
 	DB interface {
 		io.Closer
 		Callable
+
 		// ID returns the unique id.
 		ID() string
+
 		// IdleTimeout returns the idle timeout.
 		IdleTimeout() time.Duration
+
 		// MaxCapacity returns the max capacity.
 		MaxCapacity() int
+
 		// Capacity returns the capacity.
 		Capacity() int
+
 		// Weight returns the weight.
 		Weight() Weight
+
 		// SetCapacity sets the capacity.
 		SetCapacity(capacity int) error
+
 		// SetMaxCapacity sets the max capacity.
 		SetMaxCapacity(maxCapacity int) error
+
 		// SetIdleTimeout sets the idle timeout.
 		SetIdleTimeout(idleTimeout time.Duration) error
+
 		// SetWeight sets the weight.
 		SetWeight(weight Weight) error
+
+		// Variable returns the variable value.
+		Variable(ctx context.Context, name string) (string, error)
 	}
 
 	// Executable represents an executor which can send sql request.
diff --git a/pkg/runtime/ast/expression_atom.go b/pkg/runtime/ast/expression_atom.go
index e46f49150..10d1c4072 100644
--- a/pkg/runtime/ast/expression_atom.go
+++ b/pkg/runtime/ast/expression_atom.go
@@ -47,6 +47,12 @@ var (
 	_ ExpressionAtom = (*IntervalExpressionAtom)(nil)
 )
 
+var _compat80Dict = map[string]string{
+	"query_cache_size": "'1048576'",
+	"query_cache_type": "'OFF'",
+	"tx_isolation":     "@@transaction_isolation",
+}
+
 type expressionAtomPhantom struct{}
 
 type ExpressionAtom interface {
@@ -109,7 +115,18 @@ func (sy *SystemVariableExpressionAtom) Accept(visitor Visitor) (interface{}, er
 	return visitor.VisitAtomSystemVariable(sy)
 }
 
-func (sy *SystemVariableExpressionAtom) Restore(_ RestoreFlag, sb *strings.Builder, _ *[]int) error {
+func (sy *SystemVariableExpressionAtom) IsCompat80() bool {
+	_, ok := _compat80Dict[sy.Name]
+	return ok
+}
+
+func (sy *SystemVariableExpressionAtom) Restore(rf RestoreFlag, sb *strings.Builder, _ *[]int) error {
+	if rf.Has(RestoreCompat80) {
+		if compat80, ok := _compat80Dict[sy.Name]; ok {
+			sb.WriteString(compat80)
+			return nil
+		}
+	}
 	sb.WriteString("@@")
 	sb.WriteString(sy.Name)
 	return nil
diff --git a/pkg/runtime/ast/restore.go b/pkg/runtime/ast/restore.go
index 4651825b6..96ac03aca 100644
--- a/pkg/runtime/ast/restore.go
+++ b/pkg/runtime/ast/restore.go
@@ -26,6 +26,7 @@ const (
 
 	RestoreLowerKeyword RestoreFlag = 1 << iota // force use lower-case keyword
 	RestoreWithoutAlias
+	RestoreCompat80
 )
 
 type RestoreFlag uint32
diff --git a/pkg/runtime/function2/abs_test.go b/pkg/runtime/function2/abs_test.go
index d968393e0..00cbb17b0 100644
--- a/pkg/runtime/function2/abs_test.go
+++ b/pkg/runtime/function2/abs_test.go
@@ -63,5 +63,4 @@ func TestAbs(t *testing.T) {
 			assert.Equal(t, it.out, fmt.Sprint(out))
 		})
 	}
-
 }
diff --git a/pkg/runtime/optimize/dml/select.go b/pkg/runtime/optimize/dml/select.go
index 35f5fcfb3..9d81adcb8 100644
--- a/pkg/runtime/optimize/dml/select.go
+++ b/pkg/runtime/optimize/dml/select.go
@@ -72,7 +72,16 @@ func optimizeSelect(ctx context.Context, o *optimize.Optimizer) (proto.Plan, err
 		}
 		ret := &dml.SimpleQueryPlan{Stmt: stmt}
 		ret.BindArgs(o.Args)
-		return ret, nil
+
+		normalizedFields := make([]string, 0, len(stmt.Select))
+		for i := range stmt.Select {
+			normalizedFields = append(normalizedFields, stmt.Select[i].DisplayName())
+		}
+
+		return &dml.RenamePlan{
+			Plan:       ret,
+			RenameList: normalizedFields,
+		}, nil
 	}
 
 	// --- SIMPLE QUERY BEGIN ---
@@ -114,7 +123,15 @@ func optimizeSelect(ctx context.Context, o *optimize.Optimizer) (proto.Plan, err
 		}
 		ret.BindArgs(o.Args)
 
-		return ret, nil
+		normalizedFields := make([]string, 0, len(stmt.Select))
+		for i := range stmt.Select {
+			normalizedFields = append(normalizedFields, stmt.Select[i].DisplayName())
+		}
+
+		return &dml.RenamePlan{
+			Plan:       ret,
+			RenameList: normalizedFields,
+		}, nil
 	}
 
 	// Go through first table if no shards matched.
diff --git a/pkg/runtime/plan/dal/analyze_table.go b/pkg/runtime/plan/dal/analyze_table.go
index 269c9a04a..d5d9391ab 100644
--- a/pkg/runtime/plan/dal/analyze_table.go
+++ b/pkg/runtime/plan/dal/analyze_table.go
@@ -46,7 +46,8 @@ type AnalyzeTablePlan struct {
 func NewAnalyzeTablePlan(
 	stmt *ast.AnalyzeTableStatement,
 	shards rule.DatabaseTables,
-	shardsByName map[string]rule.DatabaseTables) *AnalyzeTablePlan {
+	shardsByName map[string]rule.DatabaseTables,
+) *AnalyzeTablePlan {
 	return &AnalyzeTablePlan{
 		Stmt:         stmt,
 		Shards:       shards,
diff --git a/pkg/runtime/plan/dml/mapping.go b/pkg/runtime/plan/dml/mapping.go
index e3b064a8a..55dab5d9f 100644
--- a/pkg/runtime/plan/dml/mapping.go
+++ b/pkg/runtime/plan/dml/mapping.go
@@ -233,7 +233,6 @@ func (vt *virtualValueVisitor) VisitFunction(node *ast.Function) (interface{}, e
 		return nil, errors.Wrapf(err, "failed to call function '%s'", funcName)
 	}
 	return res, nil
-
 }
 
 func (vt *virtualValueVisitor) VisitAtomNested(node *ast.NestedExpressionAtom) (interface{}, error) {
diff --git a/pkg/runtime/plan/dml/simple_select.go b/pkg/runtime/plan/dml/simple_select.go
index a19644611..5c5b6f2bf 100644
--- a/pkg/runtime/plan/dml/simple_select.go
+++ b/pkg/runtime/plan/dml/simple_select.go
@@ -34,7 +34,6 @@ import (
 	"github.com/arana-db/arana/pkg/runtime/ast"
 	rcontext "github.com/arana-db/arana/pkg/runtime/context"
 	"github.com/arana-db/arana/pkg/runtime/plan"
-	"github.com/arana-db/arana/pkg/util/log"
 )
 
 var _ proto.Plan = (*SimpleQueryPlan)(nil)
@@ -50,8 +49,30 @@ func (s *SimpleQueryPlan) Type() proto.PlanType {
 	return proto.PlanTypeQuery
 }
 
+func (s *SimpleQueryPlan) isCompat80Enabled(ctx context.Context, conn proto.VConn) bool {
+	var (
+		frontendVersion string
+		backendVersion  string
+	)
+
+	if ver := rcontext.Version(ctx); len(ver) > 0 {
+		frontendVersion = ver
+	}
+	if vs, ok := conn.(proto.VersionSupport); ok {
+		backendVersion, _ = vs.Version(ctx)
+	}
+
+	if len(frontendVersion) < 1 || len(backendVersion) < 1 {
+		return false
+	}
+
+	// 5.x -> 8.x+
+	return backendVersion[0] >= '8' && frontendVersion[0] < '8'
+}
+
 func (s *SimpleQueryPlan) ExecIn(ctx context.Context, conn proto.VConn) (proto.Result, error) {
 	var (
+		rf      = ast.RestoreDefault
 		sb      strings.Builder
 		indexes []int
 		res     proto.Result
@@ -63,7 +84,11 @@ func (s *SimpleQueryPlan) ExecIn(ctx context.Context, conn proto.VConn) (proto.R
 
 	discard := s.filter()
 
-	if err = s.generate(&sb, &indexes); err != nil {
+	if s.isCompat80Enabled(ctx, conn) {
+		rf |= ast.RestoreCompat80
+	}
+
+	if err = s.generate(rf, &sb, &indexes); err != nil {
 		return nil, errors.Wrap(err, "failed to generate sql")
 	}
 
@@ -72,20 +97,6 @@ func (s *SimpleQueryPlan) ExecIn(ctx context.Context, conn proto.VConn) (proto.R
 		args  = s.ToArgs(indexes)
 	)
 
-	version := rcontext.Version(ctx)
-	if strings.Compare(version, "8.0.0") >= 0 {
-		argsCacheSize57 := "@@query_cache_size"
-		argsCacheSize80 := "1048576"
-		argsCacheType57 := "@@query_cache_type"
-		argsCacheType80 := "'OFF'"
-		argsTxIso57 := "@@tx_isolation"
-		argsTxIso80 := "@@transaction_isolation"
-		query = strings.NewReplacer(
-			argsCacheSize57, argsCacheSize80,
-			argsCacheType57, argsCacheType80,
-			argsTxIso57, argsTxIso80).Replace(query)
-		log.Debugf("ComQueryFor8.0: %s", query)
-	}
 	if res, err = conn.Query(ctx, s.Database, query, args...); err != nil {
 		return nil, errors.WithStack(err)
 	}
@@ -139,11 +150,11 @@ func (s *SimpleQueryPlan) resetTable(tgt *ast.SelectStatement, table string) err
 	return nil
 }
 
-func (s *SimpleQueryPlan) generate(sb *strings.Builder, args *[]int) error {
+func (s *SimpleQueryPlan) generate(rf ast.RestoreFlag, sb *strings.Builder, args *[]int) error {
 	switch len(s.Tables) {
 	case 0:
 		// no table reset
-		if err := s.Stmt.Restore(ast.RestoreDefault, sb, args); err != nil {
+		if err := s.Stmt.Restore(rf, sb, args); err != nil {
 			return errors.WithStack(err)
 		}
 	case 1:
diff --git a/pkg/runtime/rule/shard_expr_type_test.go b/pkg/runtime/rule/shard_expr_type_test.go
index 5b88b776d..47be4c264 100644
--- a/pkg/runtime/rule/shard_expr_type_test.go
+++ b/pkg/runtime/rule/shard_expr_type_test.go
@@ -65,8 +65,8 @@ func TestNumEval(t *testing.T) {
 		evalRes, _ := expr.Eval(test.env)
 		got := ""
 		if len(evalRes.String()) > 0 {
-			//evalResFloat, _ := strconv.ParseFloat(evalRes.String(), 64)
-			//got = fmt.Sprintf("%.6g", evalResFloat)
+			// evalResFloat, _ := strconv.ParseFloat(evalRes.String(), 64)
+			// got = fmt.Sprintf("%.6g", evalResFloat)
 			got = evalRes.ToIntString()
 		}
 		fmt.Printf("\t%v => %s\n", test.env, got)
@@ -189,8 +189,8 @@ func TestCheck(t *testing.T) {
 		if test.want != "" {
 			// got := fmt.Sprintf("%.6g", expr.Eval(test.env))
 			evalRes, _ := expr.Eval(test.env)
-			//evalResFloat, _ := strconv.ParseFloat(evalRes.String(), 64)
-			//got := fmt.Sprintf("%.6g", evalResFloat)
+			// evalResFloat, _ := strconv.ParseFloat(evalRes.String(), 64)
+			// got := fmt.Sprintf("%.6g", evalResFloat)
 			got := evalRes.ToIntString()
 			if got != test.want {
 				t.Errorf("%s: %v => %s, want %s",
diff --git a/pkg/runtime/runtime.go b/pkg/runtime/runtime.go
index b6dcd9089..f82ffb4fb 100644
--- a/pkg/runtime/runtime.go
+++ b/pkg/runtime/runtime.go
@@ -71,38 +71,6 @@ var Tracer = otel.Tracer("Runtime")
 
 var errTxClosed = errors.New("transaction is closed")
 
-func NewAtomDB(node *config.Node) *AtomDB {
-	if node == nil {
-		return nil
-	}
-	r, w, err := node.GetReadAndWriteWeight()
-	if err != nil {
-		return nil
-	}
-	db := &AtomDB{
-		id:     node.Name,
-		weight: proto.Weight{R: int32(r), W: int32(w)},
-	}
-
-	raw, _ := json.Marshal(map[string]interface{}{
-		"dsn": fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?%s", node.Username, node.Password, node.Host, node.Port, node.Database, node.Parameters.String()),
-	})
-	connector, err := mysql.NewConnector(raw)
-	if err != nil {
-		panic(err)
-	}
-
-	var (
-		capacity    = config.GetConnPropCapacity(node.ConnProps, 8)
-		maxCapacity = config.GetConnPropMaxCapacity(node.ConnProps, 64)
-		idleTime    = config.GetConnPropIdleTime(node.ConnProps, 30*time.Minute)
-	)
-
-	db.pool = pools.NewResourcePool(connector.NewBackendConnection, capacity, maxCapacity, idleTime, 1, nil)
-
-	return db
-}
-
 // Runtime executes a sql statement.
 type Runtime interface {
 	proto.Executable
@@ -131,9 +99,10 @@ func Unload(schema string) error {
 }
 
 var (
-	_ proto.DB       = (*AtomDB)(nil)
-	_ proto.Callable = (*atomTx)(nil)
-	_ proto.Tx       = (*compositeTx)(nil)
+	_ proto.DB             = (*AtomDB)(nil)
+	_ proto.Callable       = (*atomTx)(nil)
+	_ proto.Tx             = (*compositeTx)(nil)
+	_ proto.VersionSupport = (*compositeTx)(nil)
 )
 
 type compositeTx struct {
@@ -144,6 +113,10 @@ type compositeTx struct {
 	txs map[string]*atomTx
 }
 
+func (tx *compositeTx) Version(ctx context.Context) (string, error) {
+	return tx.rt.Version(ctx)
+}
+
 func (tx *compositeTx) Query(ctx context.Context, db string, query string, args ...interface{}) (proto.Result, error) {
 	return tx.call(ctx, db, query, args...)
 }
@@ -398,6 +371,8 @@ func (tx *atomTx) dispose() {
 }
 
 type AtomDB struct {
+	mu sync.Mutex
+
 	id string
 
 	weight proto.Weight
@@ -406,6 +381,53 @@ type AtomDB struct {
 	closed atomic.Bool
 
 	pendingRequests atomic.Int64
+
+	variables atomic.Value // map[string]string
+}
+
+func NewAtomDB(node *config.Node) *AtomDB {
+	if node == nil {
+		return nil
+	}
+	r, w, err := node.GetReadAndWriteWeight()
+	if err != nil {
+		return nil
+	}
+	db := &AtomDB{
+		id:     node.Name,
+		weight: proto.Weight{R: int32(r), W: int32(w)},
+	}
+
+	raw, _ := json.Marshal(map[string]interface{}{
+		"dsn": fmt.Sprintf("%s:%s@tcp(%s:%d)/%s?%s", node.Username, node.Password, node.Host, node.Port, node.Database, node.Parameters.String()),
+	})
+	connector, err := mysql.NewConnector(raw)
+	if err != nil {
+		panic(err)
+	}
+
+	var (
+		capacity    = config.GetConnPropCapacity(node.ConnProps, 8)
+		maxCapacity = config.GetConnPropMaxCapacity(node.ConnProps, 64)
+		idleTime    = config.GetConnPropIdleTime(node.ConnProps, 30*time.Minute)
+	)
+
+	db.pool = pools.NewResourcePool(connector.NewBackendConnection, capacity, maxCapacity, idleTime, 1, nil)
+
+	// async fetch variables
+	go func() {
+		_, _ = db.fetchVariables(context.Background())
+	}()
+
+	return db
+}
+
+func (db *AtomDB) Variable(ctx context.Context, name string) (string, error) {
+	variables, err := db.fetchVariables(ctx)
+	if err != nil {
+		return "", perrors.WithStack(err)
+	}
+	return variables[name], nil
 }
 
 func (db *AtomDB) begin(ctx context.Context) (*atomTx, error) {
@@ -584,8 +606,65 @@ func (db *AtomDB) returnConnection(bc *mysql.BackendConnection) {
 	// log.Infof("^^^^^ return conn: active=%d, available=%d", db.pool.Active(), db.pool.Available())
 }
 
+func (db *AtomDB) fetchVariables(ctx context.Context) (map[string]string, error) {
+	var (
+		val map[string]string
+		ok  bool
+	)
+	if val, ok = db.variables.Load().(map[string]string); ok {
+		return val, nil
+	}
+
+	db.mu.Lock()
+	defer db.mu.Unlock()
+
+	if val, ok = db.variables.Load().(map[string]string); ok {
+		return val, nil
+	}
+
+	res, _, err := db.Call(ctx, "SHOW VARIABLES")
+	if err != nil {
+		return nil, perrors.Wrapf(err, "cannot fetch variables")
+	}
+
+	ds, err := res.Dataset()
+	if err != nil {
+		return nil, perrors.Wrapf(err, "cannot fetch variables")
+	}
+
+	defer ds.Close()
+
+	var (
+		newborn = make(map[string]string)
+		dest    = make([]proto.Value, 2)
+		row     proto.Row
+	)
+
+	for {
+		row, err = ds.Next()
+		if perrors.Is(err, io.EOF) {
+			break
+		}
+		if err != nil {
+			return nil, perrors.Wrapf(err, "cannot fetch variables")
+		}
+		if err = row.Scan(dest); err != nil {
+			return nil, perrors.Wrapf(err, "cannot fetch variables")
+		}
+		newborn[fmt.Sprint(dest[0])] = fmt.Sprint(dest[1])
+	}
+
+	db.variables.Store(newborn)
+
+	return newborn, nil
+}
+
 type defaultRuntime namespace.Namespace
 
+func (pi *defaultRuntime) Version(ctx context.Context) (string, error) {
+	return pi.Namespace().DB0(ctx).Variable(ctx, "version")
+}
+
 func (pi *defaultRuntime) Begin(ctx context.Context) (proto.Tx, error) {
 	_, span := Tracer.Start(ctx, "defaultRuntime.Begin")
 	defer span.End()
@@ -629,7 +708,7 @@ func (pi *defaultRuntime) Execute(ctx *proto.Context) (res proto.Result, warn ui
 	execStart := time.Now()
 	defer func() {
 		span.End()
-		var since = time.Since(execStart)
+		since := time.Since(execStart)
 		metrics.ExecuteDuration.Observe(since.Seconds())
 		if pi.Namespace().SlowThreshold() != 0 && since > pi.Namespace().SlowThreshold() {
 			pi.Namespace().SlowLogger().Warnf("slow logs elapsed %v sql %s", since, ctx.GetQuery())
diff --git a/pkg/trace/jaeger/jaeger.go b/pkg/trace/jaeger/jaeger.go
index 6e2053408..ee740be15 100644
--- a/pkg/trace/jaeger/jaeger.go
+++ b/pkg/trace/jaeger/jaeger.go
@@ -41,8 +41,7 @@ const (
 	parentKey = "traceparent"
 )
 
-type Jaeger struct {
-}
+type Jaeger struct{}
 
 func init() {
 	trace.RegisterProviders(trace.Jaeger, &Jaeger{})
diff --git a/pkg/util/match/slice_match.go b/pkg/util/match/slice_match.go
index 062e6d576..28c0c0d42 100644
--- a/pkg/util/match/slice_match.go
+++ b/pkg/util/match/slice_match.go
@@ -26,7 +26,6 @@ import (
 // Copy from
 // isEmpty gets whether the specified object is considered empty or not.
 func isEmpty(object interface{}) bool {
-
 	// get nil case out of the way
 	if object == nil {
 		return true
diff --git a/test/integration_test.go b/test/integration_test.go
index 16bee81a6..e09ef97ba 100644
--- a/test/integration_test.go
+++ b/test/integration_test.go
@@ -49,7 +49,7 @@ func TestSuite(t *testing.T) {
 		WithMySQLDatabase("employees"),
 		WithConfig("../integration_test/config/db_tbl/config.yaml"),
 		WithScriptPath("../scripts"),
-		//WithDevMode(), // NOTICE: UNCOMMENT IF YOU WANT TO DEBUG LOCAL ARANA SERVER!!!
+		// WithDevMode(), // NOTICE: UNCOMMENT IF YOU WANT TO DEBUG LOCAL ARANA SERVER!!!
 	)
 	suite.Run(t, &IntegrationSuite{su})
 }
@@ -992,3 +992,24 @@ func (s *IntegrationSuite) TestAnalyzeTable() {
 		})
 	}
 }
+
+func (s *IntegrationSuite) TestCompat80() {
+	var (
+		db = s.DB()
+		t  = s.T()
+	)
+
+	type tt struct {
+		sql string
+	}
+
+	for _, it := range [...]tt{
+		{"select @@query_cache_size,@@query_cache_type,@@tx_isolation"},
+	} {
+		t.Run(it.sql, func(t *testing.T) {
+			rows, err := db.Query(it.sql)
+			assert.NoError(t, err)
+			defer rows.Close()
+		})
+	}
+}
diff --git a/testdata/mock_runtime.go b/testdata/mock_runtime.go
index fd1345ea9..fd24629cd 100644
--- a/testdata/mock_runtime.go
+++ b/testdata/mock_runtime.go
@@ -1,3 +1,20 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 // Code generated by MockGen. DO NOT EDIT.
 // Source: github.com/arana-db/arana/pkg/proto (interfaces: VConn,Plan,Optimizer,DB)
 
@@ -356,10 +373,25 @@ func (mr *MockDBMockRecorder) SetWeight(arg0 interface{}) *gomock.Call {
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "SetWeight", reflect.TypeOf((*MockDB)(nil).SetWeight), arg0)
 }
 
+// Variable mocks base method.
+func (m *MockDB) Variable(arg0 context.Context, arg1 string) (string, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Variable", arg0, arg1)
+	ret0, _ := ret[0].(string)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// Variable indicates an expected call of Variable.
+func (mr *MockDBMockRecorder) Variable(arg0, arg1 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Variable", reflect.TypeOf((*MockDB)(nil).Variable), arg0, arg1)
+}
+
 // Weight mocks base method.
 func (m *MockDB) Weight() proto.Weight {
 	m.ctrl.T.Helper()
-	ret := m.ctrl.Call(m, "Ordinal")
+	ret := m.ctrl.Call(m, "Weight")
 	ret0, _ := ret[0].(proto.Weight)
 	return ret0
 }
@@ -367,5 +399,5 @@ func (m *MockDB) Weight() proto.Weight {
 // Weight indicates an expected call of Weight.
 func (mr *MockDBMockRecorder) Weight() *gomock.Call {
 	mr.mock.ctrl.T.Helper()
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Ordinal", reflect.TypeOf((*MockDB)(nil).Weight))
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Weight", reflect.TypeOf((*MockDB)(nil).Weight))
 }