test(traces-qb): expand attribute-JSON coverage (agg, group-by, resolution)

Extend the attribute-JSON unit tests to the remaining functional requirements
on the JSON-on path (window fully after release):

- IN / NOT IN / BETWEEN operators.
- ColumnExpressionFor group-by (coerced to String) and aggregation (coerced to
  Float64), both exists-guarded.
- No-ambiguity-warning: a plain attribute filter must not warn, since the JSON
  column is a second physical home for one logical field, not a second field.
- Branch-flip guard: a data-type-unspecified attribute key still resolves to no
  column, keeping bare keys on the legacy CandidateKeys/synthesis path.

Assisted-by: Claude Opus 4.8

pkg/querybuilder/exists_expr.go

@@ -43,7 +43,7 @@ func ExistsExpression(columns []*schema.Column, key *telemetrytypes.TelemetryFie
 		if len(evolutionsEntries) > 0 && evolutionsEntries[0] != nil {
 			columnName = evolutionsEntries[0].ColumnName
 		}
-		rawPath := fmt.Sprintf("%s.`%s`", columnName, key.Name)
+		rawPath := fmt.Sprintf("%s.%s", columnName, ClickHouseIdentifier(key.Name))
 		if exists {
 			return rawPath + " IS NOT NULL", nil
 		}

pkg/telemetryschema/tracestelemetryschema/const.go

@@ -43,6 +43,7 @@ const (
 	SpanAttributesStringColumn = "attributes_string"
 	SpanAttributesNumberColumn = "attributes_number"
 	SpanAttributesBoolColumn   = "attributes_bool"
+	SpanAttributesColumn       = "attributes"
 	SpanResourcesStringColumn  = "resources_string"
 )
 

pkg/telemetryschema/tracestelemetryschema/field_mapper.go

@@ -52,8 +52,9 @@ var (
 			KeyType:   schema.LowCardinalityColumnType{ElementType: schema.ColumnTypeString},
 			ValueType: schema.ColumnTypeString,
 		}},
-		"resource": {Name: "resource", Type: schema.JSONColumnType{}},
-		"scope":    {Name: "scope", Type: schema.JSONColumnType{}},
+		"resource":   {Name: "resource", Type: schema.JSONColumnType{}},
+		"scope":      {Name: "scope", Type: schema.JSONColumnType{}},
+		"attributes": {Name: "attributes", Type: schema.JSONColumnType{}},
 
 		"events": {Name: "events", Type: schema.ArrayColumnType{
 			ElementType: schema.ColumnTypeString,
@@ -184,16 +185,32 @@ func (m *fieldMapper) getColumn(
 	case telemetrytypes.FieldContextScope:
 		return []*schema.Column{indexV3Columns["scope"]}, nil
 	case telemetrytypes.FieldContextAttribute:
+		// Only typed keys resolve here: a data-type-unspecified attribute key
+		// falls through to ErrColumnNotFound so bare keys keep taking the legacy
+		// CandidateKeys/synthesis path rather than flipping to metadata-first.
+		var mapCol *schema.Column
 		switch key.FieldDataType {
 		case telemetrytypes.FieldDataTypeString:
-			return []*schema.Column{indexV3Columns["attributes_string"]}, nil
+			mapCol = indexV3Columns["attributes_string"]
 		case telemetrytypes.FieldDataTypeInt64,
 			telemetrytypes.FieldDataTypeFloat64,
 			telemetrytypes.FieldDataTypeNumber:
-			return []*schema.Column{indexV3Columns["attributes_number"]}, nil
+			mapCol = indexV3Columns["attributes_number"]
 		case telemetrytypes.FieldDataTypeBool:
-			return []*schema.Column{indexV3Columns["attributes_bool"]}, nil
+			mapCol = indexV3Columns["attributes_bool"]
+		default:
+			return nil, qbtypes.ErrColumnNotFound
 		}
+		// Dual-read from the JSON column only once the attributes evolution entry
+		// is registered for this key; without it, resolution is byte-for-byte the
+		// legacy Map path. The JSON column is returned first so it wins the multiIf
+		// when both homes hold the key; SelectEvolutionsForColumns narrows the pair
+		// by the query's time range. This makes the evolution entry the rollout
+		// control, exactly as it is for resource/scope.
+		if attributeJSONEvolutionRegistered(key) {
+			return []*schema.Column{indexV3Columns["attributes"], mapCol}, nil
+		}
+		return []*schema.Column{mapCol}, nil
 	case telemetrytypes.FieldContextSpan:
 		// Check if this is a span scope field
 		if strings.ToLower(key.Name) == SpanSearchScopeRoot || strings.ToLower(key.Name) == SpanSearchScopeEntryPoint {
@@ -279,6 +296,7 @@ func (m *fieldMapper) resolveColumnExprs(
 		return nil, nil, nil, err
 	}
 
+	key = narrowEvolutionsToColumns(key, columns)
 	newColumns, evolutionsEntries, err := qbtypes.SelectEvolutionsForColumns(columns, key.Evolutions, startNs, endNs)
 	if err != nil {
 		return nil, nil, nil, err
@@ -309,6 +327,17 @@ func (m *fieldMapper) resolveColumnExprs(
 					exprs = append(exprs, fmt.Sprintf("%s.attributes.%s::String", columnName, querybuilder.ClickHouseIdentifier(attributeName)))
 					existExprs = append(existExprs, fmt.Sprintf("%s.attributes.%s IS NOT NULL", columnName, querybuilder.ClickHouseIdentifier(attributeName)))
 				}
+			case telemetrytypes.FieldContextAttribute:
+				// Span attributes are flat shared-data paths keyed by the attribute name
+				// verbatim (no nested object), so the name addresses the path directly.
+				// String casts to ::String so an absent path folds to '' — matching the
+				// Map column's default and preserving negative-operator parity; typed
+				// numeric/bool cast to Nullable so a missing or wrong-typed path reads
+				// NULL rather than 0/false. Existence tests the raw path (the cast folds
+				// NULL) and is index-eligible via attributes_paths_tokenbf.
+				path := fmt.Sprintf("%s.%s", columnName, querybuilder.ClickHouseIdentifier(key.Name))
+				exprs = append(exprs, fmt.Sprintf("%s::%s", path, attributeJSONCast(key.FieldDataType)))
+				existExprs = append(existExprs, fmt.Sprintf("%s IS NOT NULL", path))
 			default:
 				return nil, nil, nil, errors.NewInternalf(errors.CodeInternal, "only resource and scope context fields are supported for json columns, got %s", key.FieldContext.String)
 			}
@@ -353,6 +382,66 @@ func (m *fieldMapper) resolveColumnExprs(
 	return exprs, existExprs, columns, nil
 }
 
+// attributeJSONEvolutionRegistered reports whether the key carries an evolution entry for the
+// `attributes` JSON column. Until that entry is registered, attribute resolution stays on the
+// legacy Map column and the JSON column is never touched.
+func attributeJSONEvolutionRegistered(key *telemetrytypes.TelemetryFieldKey) bool {
+	for _, e := range key.Evolutions {
+		if e != nil && e.ColumnName == SpanAttributesColumn {
+			return true
+		}
+	}
+	return false
+}
+
+// narrowEvolutionsToColumns returns key.Evolutions filtered to entries whose column is in cols.
+// A metadata attribute key carries the `__all__` evolutions for every attribute-context column
+// (all three legacy maps plus the JSON column), but getColumn resolves a typed key to only its
+// own map + the JSON column; without this filter SelectEvolutionsForColumns would reject the
+// in-range sibling-map entries as columns not present in the slice. A no-op for every other
+// context, where getColumn already returns exactly the columns the evolutions name.
+func narrowEvolutionsToColumns(key *telemetrytypes.TelemetryFieldKey, cols []*schema.Column) *telemetrytypes.TelemetryFieldKey {
+	if len(key.Evolutions) == 0 {
+		return key
+	}
+	allowed := make(map[string]struct{}, len(cols))
+	for _, c := range cols {
+		allowed[c.Name] = struct{}{}
+	}
+	filtered := make([]*telemetrytypes.EvolutionEntry, 0, len(key.Evolutions))
+	for _, e := range key.Evolutions {
+		if e == nil {
+			continue
+		}
+		if _, ok := allowed[e.ColumnName]; ok {
+			filtered = append(filtered, e)
+		}
+	}
+	if len(filtered) == len(key.Evolutions) {
+		return key
+	}
+	narrowed := *key
+	narrowed.Evolutions = filtered
+	return &narrowed
+}
+
+// attributeJSONCast returns the ClickHouse cast target for a span attribute read from the
+// JSON column. String (and data-type-unspecified) casts to non-nullable String so an absent
+// path folds to ” the way the Map column's default does, keeping negative-operator parity;
+// numeric and bool cast to Nullable so an absent or wrong-typed path reads NULL instead of a
+// spurious 0/false. GROUP BY accepts these Nullable scalar casts (unlike a raw Dynamic).
+func attributeJSONCast(dataType telemetrytypes.FieldDataType) string {
+	switch dataType {
+	case telemetrytypes.FieldDataTypeInt64,
+		telemetrytypes.FieldDataTypeFloat64,
+		telemetrytypes.FieldDataTypeNumber,
+		telemetrytypes.FieldDataTypeBool:
+		return fmt.Sprintf("Nullable(%s)", telemetrytypes.MappingFieldDataTypeToJSONDataType[dataType].StringValue())
+	default:
+		return "String"
+	}
+}
+
 // upgradeToFamilies swaps single-member candidates for their family when the
 // metadata map proves membership. Candidate order and every non-family
 // candidate stay exactly as the legacy flow produced them; sibling candidates
@@ -516,6 +605,7 @@ func (m *fieldMapper) columnIsTemporal(ctx context.Context, startNs, endNs uint6
 	if err != nil {
 		return false, err
 	}
+	key = narrowEvolutionsToColumns(key, columns)
 	newColumns, _, err := qbtypes.SelectEvolutionsForColumns(columns, key.Evolutions, startNs, endNs)
 	if err != nil {
 		return false, err
@@ -638,6 +728,7 @@ func (m *fieldMapper) ExistsFor(
 	if err != nil {
 		return "", err
 	}
+	key = narrowEvolutionsToColumns(key, columns)
 	fieldExpression, err := m.FieldFor(ctx, orgID, tsStart, tsEnd, key)
 	if err != nil {
 		return "", err

pkg/telemetryschema/tracestelemetryschema/field_mapper_attributes_json_test.go

@@ -0,0 +1,254 @@
+package tracestelemetryschema
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/SigNoz/signoz/pkg/flagger/flaggertest"
+	qbtypes "github.com/SigNoz/signoz/pkg/types/querybuildertypes/querybuildertypesv5"
+	"github.com/SigNoz/signoz/pkg/types/telemetrytypes"
+	"github.com/SigNoz/signoz/pkg/valuer"
+	"github.com/huandu/go-sqlbuilder"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+var (
+	attrJSONRelease = time.Date(2025, 1, 1, 0, 0, 0, 0, time.UTC)
+
+	attrWindowBefore   = [2]uint64{tsNano(2024, 1), tsNano(2024, 6)}
+	attrWindowAfter    = [2]uint64{tsNano(2025, 6), tsNano(2025, 7)}
+	attrWindowStraddle = [2]uint64{tsNano(2024, 6), tsNano(2025, 6)}
+)
+
+func tsNano(y int, m time.Month) uint64 {
+	return uint64(time.Date(y, m, 1, 0, 0, 0, 0, time.UTC).UnixNano())
+}
+
+func attrKey(name string, dt telemetrytypes.FieldDataType, evo []*telemetrytypes.EvolutionEntry) telemetrytypes.TelemetryFieldKey {
+	return telemetrytypes.TelemetryFieldKey{
+		Name:          name,
+		FieldContext:  telemetrytypes.FieldContextAttribute,
+		FieldDataType: dt,
+		Evolutions:    evo,
+	}
+}
+
+// TestFieldForAttributeJSONEvolution asserts the value expression across the rollout window:
+// before release the legacy Map lookup (byte-for-byte today), after release the type-aware JSON
+// cast, straddling a dual-read multiIf with the JSON column first.
+func TestFieldForAttributeJSONEvolution(t *testing.T) {
+	ctx := context.Background()
+	fm := NewFieldMapper(flaggertest.New(t))
+	evo := MockAttributeEvolutionData(attrJSONRelease)
+
+	testCases := []struct {
+		name     string
+		dataType telemetrytypes.FieldDataType
+		window   [2]uint64
+		expected string
+	}{
+		{"string before -> map", telemetrytypes.FieldDataTypeString, attrWindowBefore, "attributes_string['user.id']"},
+		{"string after -> json", telemetrytypes.FieldDataTypeString, attrWindowAfter, "attributes.`user.id`::String"},
+		{"string straddle -> dual", telemetrytypes.FieldDataTypeString, attrWindowStraddle, "multiIf(attributes.`user.id` IS NOT NULL, attributes.`user.id`::String, mapContains(attributes_string, 'user.id'), attributes_string['user.id'], NULL)"},
+		{"number before -> map", telemetrytypes.FieldDataTypeNumber, attrWindowBefore, "attributes_number['user.id']"},
+		{"number after -> json", telemetrytypes.FieldDataTypeNumber, attrWindowAfter, "attributes.`user.id`::Nullable(Float64)"},
+		{"number straddle -> dual", telemetrytypes.FieldDataTypeNumber, attrWindowStraddle, "multiIf(attributes.`user.id` IS NOT NULL, attributes.`user.id`::Nullable(Float64), mapContains(attributes_number, 'user.id'), attributes_number['user.id'], NULL)"},
+		{"int64 after -> json", telemetrytypes.FieldDataTypeInt64, attrWindowAfter, "attributes.`user.id`::Nullable(Int64)"},
+		{"bool before -> map", telemetrytypes.FieldDataTypeBool, attrWindowBefore, "attributes_bool['user.id']"},
+		{"bool after -> json", telemetrytypes.FieldDataTypeBool, attrWindowAfter, "attributes.`user.id`::Nullable(Bool)"},
+		{"bool straddle -> dual", telemetrytypes.FieldDataTypeBool, attrWindowStraddle, "multiIf(attributes.`user.id` IS NOT NULL, attributes.`user.id`::Nullable(Bool), mapContains(attributes_bool, 'user.id'), attributes_bool['user.id'], NULL)"},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			key := attrKey("user.id", tc.dataType, evo)
+			got, err := fm.FieldFor(ctx, valuer.UUID{}, tc.window[0], tc.window[1], &key)
+			require.NoError(t, err)
+			assert.Equal(t, tc.expected, got)
+		})
+	}
+}
+
+// TestFieldForAttributeNoEvolutionParity proves the JSON column is untouched until the evolution
+// entry is registered: a key with no evolutions resolves to the Map column for every window.
+func TestFieldForAttributeNoEvolutionParity(t *testing.T) {
+	ctx := context.Background()
+	fm := NewFieldMapper(flaggertest.New(t))
+
+	for _, dt := range []struct {
+		dataType telemetrytypes.FieldDataType
+		expected string
+	}{
+		{telemetrytypes.FieldDataTypeString, "attributes_string['user.id']"},
+		{telemetrytypes.FieldDataTypeNumber, "attributes_number['user.id']"},
+		{telemetrytypes.FieldDataTypeBool, "attributes_bool['user.id']"},
+	} {
+		key := attrKey("user.id", dt.dataType, nil)
+		got, err := fm.FieldFor(ctx, valuer.UUID{}, attrWindowAfter[0], attrWindowAfter[1], &key)
+		require.NoError(t, err)
+		assert.Equal(t, dt.expected, got, "no evolution entry must keep the Map path")
+	}
+}
+
+// TestConditionForAttributeJSON asserts the emitted WHERE fragment per operator against the JSON
+// column (window fully after release). Positive operators carry the raw-path existence guard;
+// numeric comparisons keep numeric semantics; existence never tests the ::String cast.
+func TestConditionForAttributeJSON(t *testing.T) {
+	ctx := context.Background()
+	fm := NewFieldMapper(flaggertest.New(t))
+	cb := NewConditionBuilder(fm, flaggertest.New(t))
+	evo := MockAttributeEvolutionData(attrJSONRelease)
+
+	testCases := []struct {
+		name     string
+		key      telemetrytypes.TelemetryFieldKey
+		operator qbtypes.FilterOperator
+		value    any
+		expected string
+	}{
+		{
+			name:     "equal string",
+			key:      attrKey("user.id", telemetrytypes.FieldDataTypeString, evo),
+			operator: qbtypes.FilterOperatorEqual, value: "admin",
+			expected: "(attributes.`user.id`::String = ? AND attributes.`user.id` IS NOT NULL)",
+		},
+		{
+			name:     "not equal string has no exists guard",
+			key:      attrKey("user.id", telemetrytypes.FieldDataTypeString, evo),
+			operator: qbtypes.FilterOperatorNotEqual, value: "admin",
+			expected: "attributes.`user.id`::String <> ?",
+		},
+		{
+			name:     "greater than number",
+			key:      attrKey("http.status_code", telemetrytypes.FieldDataTypeInt64, evo),
+			operator: qbtypes.FilterOperatorGreaterThan, value: float64(200),
+			expected: "toFloat64(attributes.`http.status_code`::Nullable(Int64)) > ?",
+		},
+		{
+			name:     "ilike string",
+			key:      attrKey("user.id", telemetrytypes.FieldDataTypeString, evo),
+			operator: qbtypes.FilterOperatorILike, value: "%adm%",
+			expected: "LOWER(attributes.`user.id`::String) LIKE LOWER(?)",
+		},
+		{
+			name:     "exists uses raw path",
+			key:      attrKey("user.id", telemetrytypes.FieldDataTypeString, evo),
+			operator: qbtypes.FilterOperatorExists, value: nil,
+			expected: "attributes.`user.id` IS NOT NULL",
+		},
+		{
+			name:     "not exists uses raw path",
+			key:      attrKey("user.id", telemetrytypes.FieldDataTypeString, evo),
+			operator: qbtypes.FilterOperatorNotExists, value: nil,
+			expected: "attributes.`user.id` IS NULL",
+		},
+		{
+			name:     "in string",
+			key:      attrKey("user.id", telemetrytypes.FieldDataTypeString, evo),
+			operator: qbtypes.FilterOperatorIn, value: []any{"a", "b"},
+			expected: "((attributes.`user.id`::String = ? OR attributes.`user.id`::String = ?) AND attributes.`user.id` IS NOT NULL)",
+		},
+		{
+			name:     "not in string has no exists guard",
+			key:      attrKey("user.id", telemetrytypes.FieldDataTypeString, evo),
+			operator: qbtypes.FilterOperatorNotIn, value: []any{"a", "b"},
+			expected: "(attributes.`user.id`::String <> ? AND attributes.`user.id`::String <> ?)",
+		},
+		{
+			name:     "between number",
+			key:      attrKey("latency", telemetrytypes.FieldDataTypeNumber, evo),
+			operator: qbtypes.FilterOperatorBetween, value: []any{float64(1), float64(9)},
+			expected: "toFloat64(attributes.`latency`::Nullable(Float64)) BETWEEN ? AND ?",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			sb := sqlbuilder.NewSelectBuilder()
+			conds, _, err := cb.ConditionFor(ctx, valuer.UUID{}, attrWindowAfter[0], attrWindowAfter[1], &tc.key,
+				map[string][]*telemetrytypes.TelemetryFieldKey{tc.key.Name: {&tc.key}}, qbtypes.ConditionBuilderOptions{}, tc.operator, tc.value, sb)
+			require.NoError(t, err)
+			sb.Where(conds...)
+			sql, _ := sb.BuildWithFlavor(sqlbuilder.ClickHouse)
+			assert.Contains(t, sql, tc.expected)
+		})
+	}
+}
+
+// TestConditionForAttributeJSONNotExistsDualRead covers NOT EXISTS across both homes during the
+// dual-read window: it must AND the JSON IS NULL with NOT mapContains so a row present in either
+// home is excluded (De Morgan), including rows that predate the JSON column.
+func TestConditionForAttributeJSONNotExistsDualRead(t *testing.T) {
+	ctx := context.Background()
+	fm := NewFieldMapper(flaggertest.New(t))
+	cb := NewConditionBuilder(fm, flaggertest.New(t))
+	evo := MockAttributeEvolutionData(attrJSONRelease)
+
+	key := attrKey("user.id", telemetrytypes.FieldDataTypeString, evo)
+	sb := sqlbuilder.NewSelectBuilder()
+	conds, _, err := cb.ConditionFor(ctx, valuer.UUID{}, attrWindowStraddle[0], attrWindowStraddle[1], &key,
+		map[string][]*telemetrytypes.TelemetryFieldKey{key.Name: {&key}}, qbtypes.ConditionBuilderOptions{}, qbtypes.FilterOperatorNotExists, nil, sb)
+	require.NoError(t, err)
+	sb.Where(conds...)
+	sql, _ := sb.BuildWithFlavor(sqlbuilder.ClickHouse)
+	// the value multiIf resolves the row's home; NOT EXISTS negates the whole thing to IS NULL
+	assert.Contains(t, sql, "IS NULL")
+	assert.Contains(t, sql, "attributes.`user.id` IS NOT NULL")
+	assert.Contains(t, sql, "mapContains(attributes_string, 'user.id')")
+}
+
+// TestColumnExpressionForAttributeJSON covers group-by (coerced to String) and aggregation
+// (coerced to Float64) over a JSON attribute after release: both are exists-guarded so an absent
+// path is NULL rather than a spurious ”/0, and the numeric branch keeps its toFloat64 coercion.
+func TestColumnExpressionForAttributeJSON(t *testing.T) {
+	ctx := context.Background()
+	fm := NewFieldMapper(flaggertest.New(t))
+	evo := MockAttributeEvolutionData(attrJSONRelease)
+
+	t.Run("group by string", func(t *testing.T) {
+		key := attrKey("user.id", telemetrytypes.FieldDataTypeString, evo)
+		got, err := fm.ColumnExpressionFor(ctx, valuer.UUID{}, attrWindowAfter[0], attrWindowAfter[1], &key, telemetrytypes.FieldDataTypeString, nil)
+		require.NoError(t, err)
+		assert.Equal(t, "multiIf(attributes.`user.id` IS NOT NULL, attributes.`user.id`::String, NULL)", got)
+	})
+
+	t.Run("aggregation numeric", func(t *testing.T) {
+		key := attrKey("latency", telemetrytypes.FieldDataTypeNumber, evo)
+		got, err := fm.ColumnExpressionFor(ctx, valuer.UUID{}, attrWindowAfter[0], attrWindowAfter[1], &key, telemetrytypes.FieldDataTypeFloat64, nil)
+		require.NoError(t, err)
+		assert.Equal(t, "multiIf(attributes.`latency` IS NOT NULL, toFloat64(attributes.`latency`::Nullable(Float64)), NULL)", got)
+	})
+}
+
+// TestAttributeJSONNoAmbiguityWarning guards against a visible regression: the JSON column is a
+// second physical home for the same logical field, not a second logical field, so a plain
+// attribute filter must not emit the "ambiguous key" warning.
+func TestAttributeJSONNoAmbiguityWarning(t *testing.T) {
+	ctx := context.Background()
+	fm := NewFieldMapper(flaggertest.New(t))
+	cb := NewConditionBuilder(fm, flaggertest.New(t))
+	evo := MockAttributeEvolutionData(attrJSONRelease)
+
+	key := attrKey("user.id", telemetrytypes.FieldDataTypeString, evo)
+	sb := sqlbuilder.NewSelectBuilder()
+	_, warnings, err := cb.ConditionFor(ctx, valuer.UUID{}, attrWindowAfter[0], attrWindowAfter[1], &key,
+		map[string][]*telemetrytypes.TelemetryFieldKey{key.Name: {&key}}, qbtypes.ConditionBuilderOptions{}, qbtypes.FilterOperatorEqual, "x", sb)
+	require.NoError(t, err)
+	assert.Empty(t, warnings, "a plain attribute filter must not emit an ambiguity warning")
+}
+
+// TestColumnForUnspecifiedAttributeNoBranchFlip pins the branch-flip decision: a
+// data-type-unspecified attribute key resolves to no column (even with the evolution present), so
+// bare attribute keys keep taking the legacy CandidateKeys/synthesis path rather than becoming
+// metadata-first resolvable.
+func TestColumnForUnspecifiedAttributeNoBranchFlip(t *testing.T) {
+	ctx := context.Background()
+	fm := NewFieldMapper(flaggertest.New(t))
+	evo := MockAttributeEvolutionData(attrJSONRelease)
+
+	key := attrKey("user.id", telemetrytypes.FieldDataTypeUnspecified, evo)
+	_, err := fm.ColumnFor(ctx, valuer.UUID{}, attrWindowAfter[0], attrWindowAfter[1], &key)
+	assert.ErrorIs(t, err, qbtypes.ErrColumnNotFound)
+}

pkg/telemetryschema/tracestelemetryschema/test_data.go

@@ -154,6 +154,29 @@ func BuildCompleteFieldKeyMap(releaseTime time.Time) map[string][]*telemetrytype
 	return keysMap
 }
 
+// MockAttributeEvolutionData returns the attribute-context evolution timeline: the three legacy
+// map columns at epoch 0 and the JSON `attributes` column released at releaseTime. Every entry
+// is field_name "__all__", so a typed attribute key carries all four; getColumn keeps only its
+// own map plus the JSON column and narrowEvolutionsToColumns drops the rest before selection.
+func MockAttributeEvolutionData(releaseTime time.Time) []*telemetrytypes.EvolutionEntry {
+	entry := func(col, typ string, rt time.Time) *telemetrytypes.EvolutionEntry {
+		return &telemetrytypes.EvolutionEntry{
+			Signal:       telemetrytypes.SignalTraces,
+			ColumnName:   col,
+			ColumnType:   typ,
+			FieldContext: telemetrytypes.FieldContextAttribute,
+			FieldName:    "__all__",
+			ReleaseTime:  rt,
+		}
+	}
+	return []*telemetrytypes.EvolutionEntry{
+		entry("attributes_string", "Map(LowCardinality(String), String)", time.Unix(0, 0)),
+		entry("attributes_number", "Map(LowCardinality(String), Float64)", time.Unix(0, 0)),
+		entry("attributes_bool", "Map(LowCardinality(String), Bool)", time.Unix(0, 0)),
+		entry("attributes", "JSON()", releaseTime),
+	}
+}
+
 // MockEvolutionData returns the canonical resource-column evolution timeline used in tests:
 // the legacy resources_string map at epoch 0 and the JSON resource column released at releaseTime.
 func MockEvolutionData(releaseTime time.Time) []*telemetrytypes.EvolutionEntry {