Revert "cherry-pick sys variables" (#15560)

Reverts #15330

Author: sukki37

pkg/config/configuration.go

@@ -162,9 +162,6 @@ var (
 	defaultLoggerLabelKey = "role"
 	defaultLoggerLabelVal = "logging_cn"
 
-	// default sql_mode
-	dafaultSqlMode = "ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION,NO_ZERO_DATE,NO_ZERO_IN_DATE,ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES"
-
 	// default lower_case_table_names
 	defaultLowerCaseTableNames = "1"
 )
@@ -290,9 +287,6 @@ type FrontendParameters struct {
 
 	// disable select into
 	DisableSelectInto bool `toml:"disable-select-into"`
-
-	// default sql_mode default value
-	SqlMode string `toml:"sql-mode"`
 }
 
 func (fp *FrontendParameters) SetDefaultValues() {
@@ -408,10 +402,6 @@ func (fp *FrontendParameters) SetDefaultValues() {
 	if fp.CleanKillQueueInterval == 0 {
 		fp.CleanKillQueueInterval = defaultCleanKillQueueInterval
 	}
-
-	if fp.SqlMode == "" {
-		fp.SqlMode = dafaultSqlMode
-	}
 }
 
 func (fp *FrontendParameters) SetMaxMessageSize(size uint64) {

pkg/frontend/session.go

@@ -1856,19 +1856,6 @@ func (ses *Session) InitGlobalSystemVariables() error {
 		pu := ses.GetParameterUnit()
 		mp := ses.GetMemPool()
 
-		updateSqls := ses.getUpdateVariableSqlsByToml()
-		for _, sql := range updateSqls {
-			_, err = executeSQLInBackgroundSession(
-				sysTenantCtx,
-				ses,
-				mp,
-				pu,
-				sql)
-			if err != nil {
-				return err
-			}
-		}
-
 		rsset, err = executeSQLInBackgroundSession(
 			sysTenantCtx,
 			ses,
@@ -1915,19 +1902,6 @@ func (ses *Session) InitGlobalSystemVariables() error {
 		pu := ses.GetParameterUnit()
 		mp := ses.GetMemPool()
 
-		updateSqls := ses.getUpdateVariableSqlsByToml()
-		for _, sql := range updateSqls {
-			_, err = executeSQLInBackgroundSession(
-				tenantCtx,
-				ses,
-				mp,
-				pu,
-				sql)
-			if err != nil {
-				return err
-			}
-		}
-
 		rsset, err = executeSQLInBackgroundSession(
 			tenantCtx,
 			ses,
@@ -1969,24 +1943,6 @@ func (ses *Session) InitGlobalSystemVariables() error {
 	return err
 }
 
-func (ses *Session) getUpdateVariableSqlsByToml() []string {
-	updateSqls := make([]string, 0)
-	tenantInfo := ses.GetTenantInfo()
-	// sql_mode
-	if getVariableValue(ses.pu.SV.SqlMode) != gSysVarsDefs["sql_mode"].Default {
-		sqlForUpdate := getSqlForUpdateSystemVariableValue(ses.pu.SV.SqlMode, uint64(tenantInfo.GetTenantID()), "sql_mode")
-		updateSqls = append(updateSqls, sqlForUpdate)
-	}
-
-	// lower_case_table_names
-	if getVariableValue(ses.pu.SV.LowerCaseTableNames) != gSysVarsDefs["lower_case_table_names"].Default {
-		sqlForUpdate := getSqlForUpdateSystemVariableValue(getVariableValue(ses.pu.SV.LowerCaseTableNames), uint64(tenantInfo.GetTenantID()), "lower_case_table_names")
-		updateSqls = append(updateSqls, sqlForUpdate)
-	}
-
-	return updateSqls
-}
-
 func (ses *Session) GetPrivilege() *privilege {
 	ses.mu.Lock()
 	defer ses.mu.Unlock()