diff --git a/pkg/sql/catalog/descpb/structured.go b/pkg/sql/catalog/descpb/structured.go
index e89f0371cef0..6b504bd12e58 100644
--- a/pkg/sql/catalog/descpb/structured.go
+++ b/pkg/sql/catalog/descpb/structured.go
@@ -230,6 +230,11 @@ func (desc *TableDescriptor) MaterializedView() bool {
 	return desc.IsMaterializedView
 }
 
+// IsReadOnly implements the TableDescriptor interface.
+func (desc *TableDescriptor) IsReadOnly() bool {
+	return desc.IsMaterializedView || desc.GetExternal() != nil
+}
+
 // IsPhysicalTable implements the TableDescriptor interface.
 func (desc *TableDescriptor) IsPhysicalTable() bool {
 	return desc.IsSequence() || (desc.IsTable() && !desc.IsVirtualTable()) || desc.MaterializedView()
diff --git a/pkg/sql/catalog/descriptor.go b/pkg/sql/catalog/descriptor.go
index 20dab3c12669..0255dcfa46a6 100644
--- a/pkg/sql/catalog/descriptor.go
+++ b/pkg/sql/catalog/descriptor.go
@@ -337,6 +337,9 @@ type TableDescriptor interface {
 	IsPhysicalTable() bool
 	// MaterializedView returns whether this TableDescriptor is a MaterializedView.
 	MaterializedView() bool
+	// IsReadOnly returns if this table descriptor has external data, and cannot
+	// be written to.
+	IsReadOnly() bool
 	// IsAs returns true if the TableDescriptor describes a Table that was created
 	// with a CREATE TABLE AS command.
 	IsAs() bool
diff --git a/pkg/sql/catalog/replication/reader_catalog_test.go b/pkg/sql/catalog/replication/reader_catalog_test.go
index 5f5b857779dc..6f45fbed90ca 100644
--- a/pkg/sql/catalog/replication/reader_catalog_test.go
+++ b/pkg/sql/catalog/replication/reader_catalog_test.go
@@ -92,6 +92,12 @@ func TestReaderCatalog(t *testing.T) {
 	compareConn("SELECT * FROM system.role_options")
 	compareConn("SELECT * FROM system.database_role_settings")
 
+	// Validate that sequences can be selected.
+	compareConn("SELECT * FROM sq1")
+
+	// Validate that sequence operations are blocked.
+	destRunner.ExpectErr(t, "cannot execute nextval\\(\\) in a read-only transaction", "SELECT nextval('sq1')")
+	destRunner.ExpectErr(t, "cannot execute setval\\(\\) in a read-only transaction", "SELECT setval('sq1', 32)")
 	// Manipulate the schema first.
 	ddlToExec = []string{
 		"ALTER TABLE t1 ADD COLUMN j int default 32",
diff --git a/pkg/sql/sequence.go b/pkg/sql/sequence.go
index 5c244fbc93db..550eab5eaadd 100644
--- a/pkg/sql/sequence.go
+++ b/pkg/sql/sequence.go
@@ -112,6 +112,11 @@ func incrementSequenceHelper(
 			string(descriptor.DescriptorType()), descriptor.GetName())
 	}
 
+	// If the descriptor is read only block any write operations.
+	if descriptor.IsReadOnly() {
+		return 0, readOnlyError("nextval()")
+	}
+
 	var err error
 	seqOpts := descriptor.GetSequenceOpts()
 
@@ -294,6 +299,10 @@ func (p *planner) SetSequenceValueByID(
 	if err != nil {
 		return err
 	}
+	// If the descriptor is read only block any write operations.
+	if descriptor.IsReadOnly() {
+		return readOnlyError("setval()")
+	}
 	seqName, err := p.getQualifiedTableName(ctx, descriptor)
 	if err != nil {
 		return err
@@ -410,7 +419,14 @@ func (p *planner) GetSequenceValue(
 func getSequenceValueFromDesc(
 	ctx context.Context, txn *kv.Txn, codec keys.SQLCodec, desc catalog.TableDescriptor,
 ) (int64, error) {
-	keyValue, err := txn.Get(ctx, codec.SequenceKey(uint32(desc.GetID())))
+	targetID := desc.GetID()
+	// For external row data, adjust the key that we will
+	// scan.
+	if ext := desc.ExternalRowData(); ext != nil {
+		codec = keys.MakeSQLCodec(ext.TenantID)
+		targetID = desc.ExternalRowData().TableID
+	}
+	keyValue, err := txn.Get(ctx, codec.SequenceKey(uint32(targetID)))
 	if err != nil {
 		return 0, err
 	}