colexec: add support for Values core with zero rows

Release note: None

pkg/sql/colexec/bool_vec_to_sel.go

@@ -31,7 +31,7 @@ func boolOrUnknownToSelOp(
 		// If the column is of an Unknown type, then all values in that column
 		// must be NULLs, so the selection vector will always be empty, and we
 		// can simply plan a zero operator.
-		return NewZeroOp(input), nil
+		return newZeroOp(input), nil
 	default:
 		return nil, errors.Errorf("unexpectedly %s is neither bool nor unknown", typs[vecIdx])
 	}

pkg/sql/colexec/execplan.go

@@ -195,6 +195,12 @@ func isSupported(
 	case core.Noop != nil:
 		return true, nil
 
+	case core.Values != nil:
+		if core.Values.NumRows != 0 {
+			return false, errors.Newf("values core only with zero rows supported")
+		}
+		return true, nil
+
 	case core.TableReader != nil:
 		if core.TableReader.IsCheck {
 			return false, errors.Newf("scrub table reader is unsupported in vectorized")
@@ -628,6 +634,20 @@ func NewColOperator(
 			result.Op, result.IsStreaming = NewNoop(inputs[0]), true
 			result.ColumnTypes = make([]*types.T, len(spec.Input[0].ColumnTypes))
 			copy(result.ColumnTypes, spec.Input[0].ColumnTypes)
+
+		case core.Values != nil:
+			if err := checkNumIn(inputs, 0); err != nil {
+				return result, err
+			}
+			if core.Values.NumRows != 0 {
+				return result, errors.AssertionFailedf("values core only with zero rows supported, %d given", core.Values.NumRows)
+			}
+			result.Op, result.IsStreaming = NewZeroOpNoInput(), true
+			result.ColumnTypes = make([]*types.T, len(core.Values.Columns))
+			for i, col := range core.Values.Columns {
+				result.ColumnTypes[i] = col.Type
+			}
+
 		case core.TableReader != nil:
 			if err := checkNumIn(inputs, 0); err != nil {
 				return result, err
@@ -1376,7 +1396,7 @@ func (r *postProcessResult) planFilterExpr(
 	if helper.Expr == tree.DNull {
 		// The filter expression is tree.DNull meaning that it is always false, so
 		// we put a zero operator.
-		r.Op = NewZeroOp(r.Op)
+		r.Op = newZeroOp(r.Op)
 		return nil
 	}
 	var filterColumnTypes []*types.T

pkg/sql/colexec/operator.go

@@ -185,8 +185,8 @@ type zeroOperator struct {
 
 var _ colexecbase.Operator = &zeroOperator{}
 
-// NewZeroOp creates a new operator which just returns an empty batch.
-func NewZeroOp(input colexecbase.Operator) colexecbase.Operator {
+// newZeroOp creates a new operator which just returns an empty batch.
+func newZeroOp(input colexecbase.Operator) colexecbase.Operator {
 	return &zeroOperator{OneInputNode: NewOneInputNode(input)}
 }
 
@@ -198,6 +198,25 @@ func (s *zeroOperator) Next(ctx context.Context) coldata.Batch {
 	return coldata.ZeroBatch
 }
 
+type zeroOperatorNoInput struct {
+	colexecbase.ZeroInputNode
+	NonExplainable
+}
+
+var _ colexecbase.Operator = &zeroOperatorNoInput{}
+
+// NewZeroOpNoInput creates a new operator which just returns an empty batch
+// and doesn't an input.
+func NewZeroOpNoInput() colexecbase.Operator {
+	return &zeroOperatorNoInput{}
+}
+
+func (s *zeroOperatorNoInput) Init() {}
+
+func (s *zeroOperatorNoInput) Next(ctx context.Context) coldata.Batch {
+	return coldata.ZeroBatch
+}
+
 type singleTupleNoInputOperator struct {
 	colexecbase.ZeroInputNode
 	NonExplainable

pkg/sql/colflow/vectorized_flow_space_test.go

@@ -82,9 +82,9 @@ func TestVectorizeInternalMemorySpaceError(t *testing.T) {
 	for _, tc := range testCases {
 		for _, success := range []bool{true, false} {
 			t.Run(fmt.Sprintf("%s-success-expected-%t", tc.desc, success), func(t *testing.T) {
-				inputs := []colexecbase.Operator{colexec.NewZeroOp(nil)}
+				inputs := []colexecbase.Operator{colexec.NewZeroOpNoInput()}
 				if len(tc.spec.Input) > 1 {
-					inputs = append(inputs, colexec.NewZeroOp(nil))
+					inputs = append(inputs, colexec.NewZeroOpNoInput())
 				}
 				memMon := mon.MakeMonitor("MemoryMonitor", mon.MemoryResource, nil, nil, 0, math.MaxInt64, st)
 				if success {