sql: persist CanMutate on function descriptors

pkg/ccl/schemachangerccl/testdata/end_to_end/create_trigger/create_trigger.explain

@@ -30,7 +30,7 @@ Schema change plan for CREATE TRIGGER tr BEFORE INSERT OR UPDATE OR DELETE ON 
  │              ├── SetTriggerEnabled {"Enabled":true,"TableID":104,"TriggerID":1}
  │              ├── SetTriggerTiming {"Timing":{"ActionTime":1,"ForEachRow":true,"TableID":104,"TriggerID":1}}
  │              ├── SetTriggerEvents {"Events":{"TableID":104,"TriggerID":1}}
- │              ├── SetTriggerFunctionCall {"FunctionCall":{"FuncBody":"BEGIN\nRAISE NOTI...","FuncID":105,"TableID":104,"TriggerID":1}}
+ │              ├── SetTriggerFunctionCall {"FunctionCall":{"CanMutate":2,"FuncBody":"BEGIN\nRAISE NOTI...","FuncID":105,"TableID":104,"TriggerID":1}}
  │              ├── SetTriggerForwardReferences {"Deps":{"TableID":104,"TriggerID":1}}
  │              ├── UpdateTriggerBackReferencesInRelations {"TableID":104,"TriggerID":1}
  │              └── AddTriggerBackReferencesInRoutines {"BackReferencedTableID":104,"BackReferencedTriggerID":1}
@@ -66,7 +66,7 @@ Schema change plan for CREATE TRIGGER tr BEFORE INSERT OR UPDATE OR DELETE ON 
  │              ├── SetTriggerEnabled {"Enabled":true,"TableID":104,"TriggerID":1}
  │              ├── SetTriggerTiming {"Timing":{"ActionTime":1,"ForEachRow":true,"TableID":104,"TriggerID":1}}
  │              ├── SetTriggerEvents {"Events":{"TableID":104,"TriggerID":1}}
- │              ├── SetTriggerFunctionCall {"FunctionCall":{"FuncBody":"BEGIN\nRAISE NOTI...","FuncID":105,"TableID":104,"TriggerID":1}}
+ │              ├── SetTriggerFunctionCall {"FunctionCall":{"CanMutate":2,"FuncBody":"BEGIN\nRAISE NOTI...","FuncID":105,"TableID":104,"TriggerID":1}}
  │              ├── SetTriggerForwardReferences {"Deps":{"TableID":104,"TriggerID":1}}
  │              ├── UpdateTriggerBackReferencesInRelations {"TableID":104,"TriggerID":1}
  │              ├── AddTriggerBackReferencesInRoutines {"BackReferencedTableID":104,"BackReferencedTriggerID":1}

pkg/ccl/schemachangerccl/testdata/end_to_end/create_trigger/create_trigger.side_effects

@@ -47,6 +47,7 @@ upsert descriptor #104
   -  schemaLocked: true
   +  triggers:
   +  - actionTime: BEFORE
+  +    canMutate: CANNOT_MUTATE
   +    dependsOn:
   +    - 104
   +    dependsOnRoutines:
@@ -141,6 +142,7 @@ upsert descriptor #104
   -  schemaLocked: true
   +  triggers:
   +  - actionTime: BEFORE
+  +    canMutate: CANNOT_MUTATE
   +    dependsOn:
   +    - 104
   +    dependsOnRoutines:

pkg/ccl/schemachangerccl/testdata/end_to_end/drop_table_trigger/drop_table_trigger.side_effects

@@ -36,6 +36,7 @@ upsert descriptor #104
   -  schemaLocked: true
   -  triggers:
   -  - actionTime: BEFORE
+  -    canMutate: CANNOT_MUTATE
   -    dependsOn:
   -    - 104
   -    dependsOnRoutines:
@@ -112,6 +113,7 @@ upsert descriptor #104
   -  schemaLocked: true
   -  triggers:
   -  - actionTime: BEFORE
+  -    canMutate: CANNOT_MUTATE
   -    dependsOn:
   -    - 104
   -    dependsOnRoutines:

pkg/ccl/schemachangerccl/testdata/end_to_end/drop_trigger/drop_trigger.side_effects

@@ -33,6 +33,7 @@ upsert descriptor #104
      schemaLocked: true
   -  triggers:
   -  - actionTime: BEFORE
+  -    canMutate: CANNOT_MUTATE
   -    dependsOn:
   -    - 104
   -    dependsOnRoutines:
@@ -90,6 +91,7 @@ upsert descriptor #104
      schemaLocked: true
   -  triggers:
   -  - actionTime: BEFORE
+  -    canMutate: CANNOT_MUTATE
   -    dependsOn:
   -    - 104
   -    dependsOnRoutines:

pkg/sql/catalog/catpb/function.proto

@@ -46,6 +46,12 @@ message Function {
     INVOKER = 0;
     DEFINER = 1;
   }
+
+  enum CanMutate {
+    UNKNOWN_CAN_MUTATE = 0;
+    CAN_MUTATE = 1;
+    CANNOT_MUTATE = 2;
+  }
 }
 
 // These wrappers are for the convenience of referencing the enum types from a

pkg/sql/catalog/descpb/structured.proto

@@ -590,6 +590,24 @@ message TriggerDescriptor {
   // DependsOnRoutines are the IDs of the user-defined routines that this
   // trigger depends on.
   repeated uint32 depends_on_routines = 15  [(gogoproto.casttype) = "ID"];
+
+  // CanMutate indicates whether the trigger function body can perform
+  // mutations. This includes direct DML statements (INSERT, UPDATE, DELETE,
+  // UPSERT), mutations inside CTEs or subqueries, and calls to other routines
+  // that themselves can mutate. It is computed at CREATE TRIGGER time by
+  // inspecting the CanMutate logical property of the built trigger function
+  // body, and persisted so it is available without rebuilding the body.
+  //
+  // Unlike a trigger function's own descriptor, the trigger descriptor has the
+  // table binding required to build the body, so the value is meaningful here.
+  // See the FunctionDescriptor.can_mutate field for the analogous field on
+  // function descriptors.
+  //
+  // UNKNOWN_CAN_MUTATE (the zero value) indicates that the mutation status has
+  // not been determined. This is the case for trigger descriptors created
+  // before this field was introduced. When unknown, consumers fall back to
+  // deriving the value from the built trigger function body.
+  optional cockroach.sql.catalog.catpb.Function.CanMutate can_mutate = 16 [(gogoproto.nullable) = false];
 }
 
 // ConstraintToUpdate represents a constraint to be added to the table and
@@ -2039,7 +2057,22 @@ message FunctionDescriptor {
   optional uint32 replicated_pcr_version = 24 [(gogoproto.nullable) = false,
     (gogoproto.customname) = "ReplicatedPCRVersion", (gogoproto.casttype) = "DescriptorVersion"];
 
-  // Next field id is 25
+  // CanMutate indicates whether the routine body can perform mutations.
+  // This includes direct DML statements (INSERT, UPDATE, DELETE, UPSERT),
+  // mutations inside CTEs or subqueries, and calls to other routines that
+  // themselves can mutate. It is computed at CREATE FUNCTION time by
+  // inspecting the CanMutate logical property of the built body
+  // statements, and persisted so that it is available at execution time
+  // without needing to build the routine body.
+  //
+  // UNKNOWN_CAN_MUTATE (the zero value) indicates that the mutation status
+  // has not been determined. This is the case for function descriptors
+  // created before this field was introduced. When unknown, consumers must
+  // fall back to inspecting the body RelExprs to determine whether the
+  // routine can mutate.
+  optional cockroach.sql.catalog.catpb.Function.CanMutate can_mutate = 25 [(gogoproto.nullable) = false];
+
+  // Next field id is 26
 }
 
 // Descriptor is a union type for descriptors for tables, schemas, databases,

pkg/sql/catalog/descriptor.go

@@ -1177,6 +1177,9 @@ type FunctionDescriptor interface {
 
 	// GetSecurity returns the security specification of this function.
 	GetSecurity() catpb.Function_Security
+
+	// GetCanMutate returns the CanMutate field of this function descriptor.
+	GetCanMutate() catpb.Function_CanMutate
 }
 
 // FilterDroppedDescriptor returns an error if the descriptor state is DROP.

pkg/sql/catalog/funcdesc/func_desc.go

@@ -643,6 +643,11 @@ func (desc *Mutable) SetSecurity(v catpb.Function_Security) {
 	desc.Security = v
 }
 
+// SetCanMutate sets the CanMutate field on the function descriptor.
+func (desc *Mutable) SetCanMutate(v catpb.Function_CanMutate) {
+	desc.CanMutate = v
+}
+
 // SetName sets the function name.
 func (desc *Mutable) SetName(n string) {
 	desc.Name = n
@@ -1027,6 +1032,11 @@ func (desc *immutable) GetSecurity() catpb.Function_Security {
 	return desc.Security
 }
 
+// GetCanMutate implements the FunctionDescriptor interface.
+func (desc *immutable) GetCanMutate() catpb.Function_CanMutate {
+	return desc.CanMutate
+}
+
 func (desc *immutable) ToOverload() (ret *tree.Overload, err error) {
 	routineType := tree.UDFRoutine
 	if desc.IsProcedure() {
@@ -1075,10 +1085,36 @@ func (desc *immutable) ToOverload() (ret *tree.Overload, err error) {
 		ret.Class = tree.GeneratorClass
 	}
 	ret.SecurityMode = desc.getCreateExprSecurity()
+	ret.CanMutate = canMutateToOverload(desc.FunctionDescriptor.CanMutate)
 
 	return ret, nil
 }
 
+// canMutateToOverload converts the proto CanMutate enum to the tree type.
+func canMutateToOverload(cm catpb.Function_CanMutate) tree.RoutineCanMutate {
+	switch cm {
+	case catpb.Function_CAN_MUTATE:
+		return tree.RoutineMutates
+	case catpb.Function_CANNOT_MUTATE:
+		return tree.RoutineDoesNotMutate
+	default:
+		return tree.RoutineCanMutateUnknown
+	}
+}
+
+// CanMutateToProto converts a RoutineCanMutate enum to the proto enum for
+// persistence on the function descriptor.
+func CanMutateToProto(cm tree.RoutineCanMutate) catpb.Function_CanMutate {
+	switch cm {
+	case tree.RoutineMutates:
+		return catpb.Function_CAN_MUTATE
+	case tree.RoutineDoesNotMutate:
+		return catpb.Function_CANNOT_MUTATE
+	default:
+		return catpb.Function_UNKNOWN_CAN_MUTATE
+	}
+}
+
 func (desc *immutable) getOverloadVolatility() (volatility.V, error) {
 	var ret volatility.V
 	switch desc.Volatility {

pkg/sql/catalog/tabledesc/validate_test.go

@@ -350,6 +350,7 @@ var validationMap = []struct {
 			"IsProcedure":                   {status: thisFieldReferencesNoObjects},
 			"Security":                      {status: thisFieldReferencesNoObjects},
 			"ReplicatedPCRVersion":          {status: thisFieldReferencesNoObjects},
+			"CanMutate":                     {status: thisFieldReferencesNoObjects},
 		},
 	},
 	{
@@ -370,6 +371,7 @@ var validationMap = []struct {
 			"DependsOn":          {status: iSolemnlySwearThisFieldIsValidated},
 			"DependsOnTypes":     {status: iSolemnlySwearThisFieldIsValidated},
 			"DependsOnRoutines":  {status: iSolemnlySwearThisFieldIsValidated},
+			"CanMutate":          {status: thisFieldReferencesNoObjects},
 		},
 	},
 }