SET LOCAL support

go.mod

@@ -6,10 +6,10 @@ require (
 	github.com/PuerkitoBio/goquery v1.8.1
 	github.com/cockroachdb/apd/v3 v3.2.3
 	github.com/cockroachdb/errors v1.7.5
-	github.com/dolthub/dolt/go v0.40.5-0.20260828173935-dc4e79209ce0
+	github.com/dolthub/dolt/go v0.40.5-0.20260901102237-645f6accd917
 	github.com/dolthub/eventsapi_schema v0.0.0-20260715220557-d9b4a1c6b4d4
 	github.com/dolthub/flatbuffers/v23 v23.3.3-dh.2
-	github.com/dolthub/go-mysql-server v0.20.1-0.20260831214236-aa1f8e45655b
+	github.com/dolthub/go-mysql-server v0.20.1-0.20260901192735-5d6be3976cd5
 	github.com/dolthub/pg_query_go/v6 v6.0.0-20251215122834-fb20be4254d1
 	github.com/dolthub/sqllogictest/go v0.0.0-20260624223518-788480b24166
 	github.com/dolthub/vitess v0.0.0-20260828193927-f9eb707fd659

go.sum

@@ -246,8 +246,8 @@ github.com/dolthub/aws-sdk-go-ini-parser v0.0.0-20250305001723-2821c37f6c12 h1:I
 github.com/dolthub/aws-sdk-go-ini-parser v0.0.0-20250305001723-2821c37f6c12/go.mod h1:rN7X8BHwkjPcfMQQ2QTAq/xM3leUSGLfb+1Js7Y6TVo=
 github.com/dolthub/dolt-mcp v0.3.4 h1:AyG5cw+fNWXDHXujtQnqUPZrpWtPg6FN6yYtjv1pP44=
 github.com/dolthub/dolt-mcp v0.3.4/go.mod h1:bCZ7KHvDYs+M0e+ySgmGiNvLhcwsN7bbf5YCyillLrk=
-github.com/dolthub/dolt/go v0.40.5-0.20260828173935-dc4e79209ce0 h1:VrCgqBaqm3WT7olZRdYGScPGsZdzd4S67M/hD/R00f8=
-github.com/dolthub/dolt/go v0.40.5-0.20260828173935-dc4e79209ce0/go.mod h1:vGmWnRXHjHe+BYLeaC2WCte5lpzEXdcKFt4mFiKD2yc=
+github.com/dolthub/dolt/go v0.40.5-0.20260901102237-645f6accd917 h1:lx7XhihYV9y0H5N6US13VlN5JGjT7FB9eksXXA7sMCU=
+github.com/dolthub/dolt/go v0.40.5-0.20260901102237-645f6accd917/go.mod h1:D1MXT5V70cZfYR8eKpijs/1vsOFgSGdmr9hk83gi73Y=
 github.com/dolthub/eventsapi_schema v0.0.0-20260715220557-d9b4a1c6b4d4 h1:0mg9QEFdkkBwJMxvz1tCjHYmfG2iIC6aShj1InDq9/M=
 github.com/dolthub/eventsapi_schema v0.0.0-20260715220557-d9b4a1c6b4d4/go.mod h1:SSLraQS/jGLYFgff3vuZ+JbVUct6vyEeMzjLBqWqoyM=
 github.com/dolthub/flatbuffers/v23 v23.3.3-dh.2 h1:u3PMzfF8RkKd3lB9pZ2bfn0qEG+1Gms9599cr0REMww=
@@ -256,8 +256,8 @@ github.com/dolthub/fslock v0.0.5 h1:QoXhBhgY1oumHE26qyE7tgmXUT8qjJwxsIzo54O/B/k=
 github.com/dolthub/fslock v0.0.5/go.mod h1:sdofYYqE0D79zNZyB4/kmlnsQOVap1C2yByjGKSirEM=
 github.com/dolthub/go-icu-regex v0.0.0-20260610153742-72563bc7ca83 h1:FEMjCGEroDnY/BXyAffVZxUpXhP2GpoUJyyq5KaLn8c=
 github.com/dolthub/go-icu-regex v0.0.0-20260610153742-72563bc7ca83/go.mod h1:F3cnm+vMRK1HaU6+rNqQrOCyR03HHhR1GWG2gnPOqaE=
-github.com/dolthub/go-mysql-server v0.20.1-0.20260831214236-aa1f8e45655b h1:O9lohpiOrRXsdogCmnxLT2P7ox4u+Ilat6pl6b8f2+w=
-github.com/dolthub/go-mysql-server v0.20.1-0.20260831214236-aa1f8e45655b/go.mod h1:CtDdfkAma4klv+UQbEmV4AkVvkSyXf/V3iRpIDu6c2I=
+github.com/dolthub/go-mysql-server v0.20.1-0.20260901192735-5d6be3976cd5 h1:OjIEbos9AZW660TkKANOzDjMnOZgFchyJkhcXXulCcE=
+github.com/dolthub/go-mysql-server v0.20.1-0.20260901192735-5d6be3976cd5/go.mod h1:CtDdfkAma4klv+UQbEmV4AkVvkSyXf/V3iRpIDu6c2I=
 github.com/dolthub/gozstd v0.0.0-20240423170813-23a2903bca63 h1:OAsXLAPL4du6tfbBgK0xXHZkOlos63RdKYS3Sgw/dfI=
 github.com/dolthub/gozstd v0.0.0-20240423170813-23a2903bca63/go.mod h1:lV7lUeuDhH5thVGDCKXbatwKy2KW80L4rMT46n+Y2/Q=
 github.com/dolthub/ishell v0.0.0-20260414231531-5f031e3e9037 h1:oIW9HwuWrhxv+4HZxA+QQSKHLqWFyXZ2FmNjUYwkdiM=

server/ast/set_var.go

@@ -20,6 +20,7 @@ import (
 
 	"github.com/cockroachdb/errors"
 	"github.com/dolthub/go-mysql-server/sql"
+	"github.com/dolthub/go-mysql-server/sql/planbuilder"
 	vitess "github.com/dolthub/vitess/go/vt/sqlparser"
 
 	"github.com/dolthub/doltgresql/postgres/parser/sem/tree"
@@ -42,9 +43,9 @@ func nodeSetVar(ctx *Context, node *tree.SetVar) (vitess.Statement, error) {
 	if node.Namespace == "" && !config.IsValidPostgresConfigParameter(node.Name) && !config.IsValidDoltConfigParameter(node.Name) {
 		return nil, errors.Errorf(`ERROR: unrecognized configuration parameter "%s"`, node.Name)
 	}
-	if node.IsLocal {
-		// TODO: takes effect for only the current transaction rather than the current session.
-		return nil, errors.Errorf("SET LOCAL is not yet supported")
+	if node.IsLocal && node.Namespace != "" {
+		// TODO: support transaction-local values for custom (namespaced) parameters, which are session user vars
+		return nil, errors.Errorf("SET LOCAL is not yet supported for customized options")
 	}
 	var expr vitess.Expr
 	var err error
@@ -71,7 +72,11 @@ func nodeSetVar(ctx *Context, node *tree.SetVar) (vitess.Statement, error) {
 		// Dolt's cluster replication variables) are routed to their declared scope directly, symmetric with
 		// current_setting() reading them from the global scope.
 		scope := vitess.SetScope_Session
-		if svScope, ok := config.GlobalOnlySystemVariableScope(node.Name); ok {
+		if node.IsLocal {
+			// SET LOCAL only applies for the duration of the current transaction; the connection handler restores
+			// the session values when the transaction ends. Global-only variables are rejected by the engine.
+			scope = planbuilder.SetScope_TransactionLocal
+		} else if svScope, ok := config.GlobalOnlySystemVariableScope(node.Name); ok {
 			switch svScope {
 			case sql.SystemVariableScope_Persist:
 				scope = vitess.SetScope_Persist

server/config/parameters.go

@@ -97,6 +97,12 @@ func (p *Parameter) GetSessionScope() sql.SystemVariableScope {
 	return GetPgsqlScope(PsqlScopeSession)
 }
 
+// GetLocalScope implements sql.SystemVariable. Any parameter that can be set at session scope can also be set with
+// transaction-local scope (SET LOCAL).
+func (p *Parameter) GetLocalScope() sql.SystemVariableScope {
+	return GetPgsqlScope(PsqlScopeLocal)
+}
+
 // SetDefault implements sql.SystemVariable.
 func (p *Parameter) SetDefault(a any) {
 	if validatedVal, ok := p.ValidateFunc(p.Default, a); ok {
@@ -223,8 +229,8 @@ func (p *PgsqlScope) SetValue(ctx *sql.Context, name string, val any) error {
 		err := ctx.SetSessionVariable(ctx, name, val)
 		return err
 	case PsqlScopeLocal:
-		// TODO: support LOCAL scope
-		return cerrors.Errorf("unsupported scope `%v` on configuration parameter `%s`", p.Type, name)
+		_ = core.SetDateStyleOutputFormat(ctx, "")
+		return ctx.Session.SetTransactionLocalVariable(ctx, name, val)
 	default:
 		return cerrors.Errorf("unable to set `%s` due to unknown scope `%v`", name, p.Type)
 	}
@@ -240,8 +246,12 @@ func (p *PgsqlScope) GetValue(ctx *sql.Context, name string, _ sql.CollationID)
 		}
 		return val, nil
 	case PsqlScopeLocal:
-		// TODO: support LOCAL scope
-		return nil, cerrors.Errorf("unsupported scope `%v` on configuration parameter `%s`", p.Type, name)
+		// The session value already reflects any transaction-local override
+		val, err := ctx.GetSessionVariable(ctx, name)
+		if err != nil {
+			return nil, err
+		}
+		return val, nil
 	default:
 		return nil, cerrors.Errorf("unknown scope `%v` on configuration parameter `%s`", p.Type, name)
 	}

server/connection_handler.go

@@ -44,6 +44,7 @@ import (
 	"github.com/mitchellh/go-ps"
 	"github.com/sirupsen/logrus"
 
+	"github.com/dolthub/doltgresql/core"
 	"github.com/dolthub/doltgresql/core/dataloader"
 	"github.com/dolthub/doltgresql/postgres/parser/parser"
 	psql "github.com/dolthub/doltgresql/postgres/parser/parser/sql"
@@ -604,6 +605,7 @@ func (h *ConnectionHandler) handleQueryOutsideEngine(query ConvertedQuery) (hand
 			// A COMMIT issued inside a failed transaction block ends the block by rolling it back, and reports
 			// ROLLBACK to the client to indicate that the transaction's effects were discarded.
 			h.transactionState = idleTransactionState
+			h.clearTransactionLocalVars()
 			if err := h.runEngineTransactionControl("ROLLBACK"); err != nil {
 				return true, true, err
 			}
@@ -612,9 +614,11 @@ func (h *ConnectionHandler) handleQueryOutsideEngine(query ConvertedQuery) (hand
 		// A COMMIT closes the current transaction block, whether explicit or implicit. Any statements that
 		// follow it in the same Query message (or extended-query batch) run in a new implicit transaction block.
 		h.transactionState = idleTransactionState
+		h.clearTransactionLocalVars()
 	case *sqlparser.Rollback:
 		// Like COMMIT, a ROLLBACK closes the current transaction block, whether explicit, implicit, or failed.
 		h.transactionState = idleTransactionState
+		h.clearTransactionLocalVars()
 	case *sqlparser.Savepoint:
 		if !h.transactionState.inExplicitTransactionBlock() {
 			return true, true, noActiveTransactionError("SAVEPOINT")
@@ -1326,6 +1330,7 @@ func (h *ConnectionHandler) commitImplicitTransaction() error {
 		return nil
 	}
 	h.transactionState = idleTransactionState
+	h.clearTransactionLocalVars()
 	if h.restoredAutoCommitWithoutTransaction() {
 		return nil
 	}
@@ -1344,6 +1349,7 @@ func (h *ConnectionHandler) rollbackImplicitTransaction() {
 		return
 	}
 	h.transactionState = idleTransactionState
+	h.clearTransactionLocalVars()
 	if h.restoredAutoCommitWithoutTransaction() {
 		return
 	}
@@ -1352,6 +1358,23 @@ func (h *ConnectionHandler) rollbackImplicitTransaction() {
 	}
 }
 
+// clearTransactionLocalVars removes any system variable values that were set with transaction-local scope
+// (SET LOCAL, or set_config with is_local), restoring the variables' session values. Called whenever the current
+// transaction block ends, whether by COMMIT or ROLLBACK: Postgres reverts SET LOCAL values in both cases.
+func (h *ConnectionHandler) clearTransactionLocalVars() {
+	ctx, err := h.doltgresHandler.NewContext(context.Background(), h.mysqlConn, "")
+	if err != nil {
+		logrus.Warnf("error creating context to clear transaction-local variables: %s", err)
+		return
+	}
+	if err = ctx.Session.ClearTransactionLocalVariables(ctx); err != nil {
+		logrus.Warnf("error clearing transaction-local variables: %s", err)
+		return
+	}
+	// Reset any cached variables in ContextValues, in case a cached parameter (e.g. datestyle) was overridden
+	_ = core.SetDateStyleOutputFormat(ctx, "")
+}
+
 // restoredAutoCommitWithoutTransaction returns whether the session no longer has an engine transaction in
 // progress, restoring the session's autocommit behavior if so. Some statements end the engine transaction
 // themselves as a side effect of executing (e.g. dolt_assume_cluster_role, which also poisons the session

server/functions/set_config.go

@@ -44,11 +44,6 @@ var set_config_text_text_boolean = framework.Function3{
 			newValue = ""
 		}
 
-		if isLocal == true {
-			// TODO: If isLocal is true, then the config setting should only persist for the current transaction
-			return nil, errors.Errorf("setting configuration values for the current transaction is not supported yet")
-		}
-
 		settingNameStr, err := framework.UnwrapString(ctx, settingName)
 		if err != nil {
 			return nil, err
@@ -61,7 +56,13 @@ var set_config_text_text_boolean = framework.Function3{
 		// set_config can set system configuration or user configuration. System configuration settings are in top
 		// level settings, while user configuration settings are namespaced.
 		isUserConfig := strings.Contains(settingNameStr, ".")
-		if isUserConfig {
+		if isLocal == true {
+			// A transaction-local value overrides the session value until the transaction ends, when the
+			// connection handler clears it
+			if err := ctx.Session.SetTransactionLocalVariable(ctx, settingName.(string), newValue.(string)); err != nil {
+				return nil, err
+			}
+		} else if isUserConfig {
 			if err := ctx.SetUserVariable(ctx, settingNameStr, newValueStr, pgtypes.Text); err != nil {
 				return nil, err
 			}

testing/generation/command_docs/output/set_test.go

@@ -38,16 +38,16 @@ func TestSet(t *testing.T) {
 		Parses("SET LOCAL configuration_parameter = DEFAULT"),
 		Converts("SET TIME ZONE 1"),
 		Converts("SET SESSION TIME ZONE 1"),
-		Parses("SET LOCAL TIME ZONE 1"),
+		Converts("SET LOCAL TIME ZONE 1"),
 		Converts("SET TIME ZONE ' 1 '"),
 		Converts("SET SESSION TIME ZONE ' 1 '"),
-		Parses("SET LOCAL TIME ZONE ' 1 '"),
+		Converts("SET LOCAL TIME ZONE ' 1 '"),
 		Converts("SET TIME ZONE LOCAL"),
 		Converts("SET SESSION TIME ZONE LOCAL"),
-		Parses("SET LOCAL TIME ZONE LOCAL"),
+		Converts("SET LOCAL TIME ZONE LOCAL"),
 		Converts("SET TIME ZONE DEFAULT"),
 		Converts("SET SESSION TIME ZONE DEFAULT"),
-		Parses("SET LOCAL TIME ZONE DEFAULT"),
+		Converts("SET LOCAL TIME ZONE DEFAULT"),
 	}
 	RunTests(t, tests)
 }