fix(fields): drop empty related values before the limit

Assisted-by: Claude Opus 5.5

docs/api/openapi.yml

@@ -15826,13 +15826,23 @@ paths:
             where it is case-sensitive and % and _ act as wildcards. For keys, a context
             prefix such as resource.service.name sets fieldContext when it is empty.'
           type: string
-      - description: The key whose values to return, such as service.name. A context
-          prefix such as resource.service.name sets fieldContext when it is empty.
+      - description: 'The key whose values to return, such as service.name. With fieldContext
+          set, it is the stored name as is. Otherwise a context prefix such as resource.service.name
+          sets the context and a type suffix such as service.name:string sets fieldDataType
+          when that is empty; as in filter expressions, a prefixed name other than
+          resource. also matches a key stored under the full name, whose values come
+          first: log.level returns values of a key named log.level, then of the log
+          field level.'
         in: query
         name: name
         schema:
-          description: The key whose values to return, such as service.name. A context
-            prefix such as resource.service.name sets fieldContext when it is empty.
+          description: 'The key whose values to return, such as service.name. With
+            fieldContext set, it is the stored name as is. Otherwise a context prefix
+            such as resource.service.name sets the context and a type suffix such
+            as service.name:string sets fieldDataType when that is empty; as in filter
+            expressions, a prefixed name other than resource. also matches a key stored
+            under the full name, whose values come first: log.level returns values
+            of a key named log.level, then of the log field level.'
           type: string
       - description: Filter expression already applied in the explorer. When set,
           relatedValues lists the values seen on data matching it.
@@ -28411,13 +28421,23 @@ paths:
             where it is case-sensitive and % and _ act as wildcards. For keys, a context
             prefix such as resource.service.name sets fieldContext when it is empty.'
           type: string
-      - description: The key whose values to return, such as service.name. A context
-          prefix such as resource.service.name sets fieldContext when it is empty.
+      - description: 'The key whose values to return, such as service.name. With fieldContext
+          set, it is the stored name as is. Otherwise a context prefix such as resource.service.name
+          sets the context and a type suffix such as service.name:string sets fieldDataType
+          when that is empty; as in filter expressions, a prefixed name other than
+          resource. also matches a key stored under the full name, whose values come
+          first: log.level returns values of a key named log.level, then of the log
+          field level.'
         in: query
         name: name
         schema:
-          description: The key whose values to return, such as service.name. A context
-            prefix such as resource.service.name sets fieldContext when it is empty.
+          description: 'The key whose values to return, such as service.name. With
+            fieldContext set, it is the stored name as is. Otherwise a context prefix
+            such as resource.service.name sets the context and a type suffix such
+            as service.name:string sets fieldDataType when that is empty; as in filter
+            expressions, a prefixed name other than resource. also matches a key stored
+            under the full name, whose values come first: log.level returns values
+            of a key named log.level, then of the log field level.'
           type: string
       - description: Filter expression already applied in the explorer. When set,
           relatedValues lists the values seen on data matching it.

pkg/telemetrymetadata/context_prefixed_values_test.go

@@ -0,0 +1,50 @@
+package telemetrymetadata
+
+import (
+	"context"
+	"testing"
+
+	cmock "github.com/SigNoz/clickhouse-go-mock"
+	"github.com/SigNoz/signoz/pkg/flagger/flaggertest"
+	"github.com/SigNoz/signoz/pkg/instrumentation/instrumentationtest"
+	"github.com/SigNoz/signoz/pkg/telemetrystore"
+	"github.com/SigNoz/signoz/pkg/telemetrystore/telemetrystoretest"
+	"github.com/SigNoz/signoz/pkg/types/telemetrytypes"
+	"github.com/SigNoz/signoz/pkg/valuer"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetAllValuesExactNameFirst(t *testing.T) {
+	mockTelemetryStore := telemetrystoretest.New(telemetrystore.Config{}, &regexMatcher{})
+	mock := mockTelemetryStore.Mock()
+	metadata := NewTelemetryMetaStore(instrumentationtest.New().ToProviderSettings(), mockTelemetryStore, flaggertest.New(t))
+
+	boolColumns := []cmock.ColumnType{{Name: "1", Type: "UInt8"}}
+	valueColumns := []cmock.ColumnType{{Name: "string_value", Type: "String"}, {Name: "number_value", Type: "Float64"}}
+
+	mock.ExpectQuery(`SELECT 1 FROM .*tag_key = \? AND tag_data_type = \? LIMIT`).
+		WithArgs("log.level", "bool", 1).
+		WillReturnRows(cmock.NewRows(boolColumns, [][]any{}))
+	mock.ExpectQuery(`SELECT DISTINCT string_value, number_value FROM .*tag_key = \? AND tag_data_type <> \? LIMIT`).
+		WithArgs("log.level", "bool", 3).
+		WillReturnRows(cmock.NewRows(valueColumns, [][]any{{"warn", float64(0)}, {"info", float64(0)}}))
+	mock.ExpectQuery(`SELECT 1 FROM .*tag_key = \? AND tag_data_type = \? AND tag_type = \?`).
+		WithArgs("level", "bool", "logfield", 1).
+		WillReturnRows(cmock.NewRows(boolColumns, [][]any{}))
+	mock.ExpectQuery(`SELECT DISTINCT string_value, number_value FROM .*tag_key = \? AND tag_data_type <> \? AND tag_type = \?`).
+		WithArgs("level", "bool", "logfield", 3).
+		WillReturnRows(cmock.NewRows(valueColumns, [][]any{{"info", float64(0)}, {"debug", float64(0)}}))
+
+	selector := telemetrytypes.NewFieldValueSelectorFromPostableFieldValueParams(telemetrytypes.PostableFieldValueParams{
+		Name:                    "log.level",
+		PostableFieldKeysParams: telemetrytypes.PostableFieldKeysParams{Signal: telemetrytypes.SignalLogs, Limit: 2},
+	})
+
+	values, complete, err := metadata.GetAllValues(context.Background(), valuer.GenerateUUID(), selector)
+	require.NoError(t, err)
+
+	assert.Equal(t, []string{"warn", "info"}, values.StringValues)
+	assert.False(t, complete)
+	assert.NoError(t, mock.ExpectationsWereMet())
+}

pkg/telemetrymetadata/metadata.go

@@ -1401,6 +1401,8 @@ func (t *telemetryMetaStore) getRelatedValues(ctx context.Context, orgID valuer.
 	}
 
 	sb := sqlbuilder.Select("DISTINCT " + selectColumn).From(t.relatedMetadataDBName + "." + t.relatedMetadataTblName)
+	// rows without the key read as empty; drop them so they do not count towards the limit
+	sb.Where(fmt.Sprintf("notEmpty(%s)", selectColumn))
 
 	if len(fieldValueSelector.ExistingQuery) != 0 {
 		keySelectors := querybuilder.QueryStringToKeysSelectors(fieldValueSelector.ExistingQuery)
@@ -1517,7 +1519,24 @@ func (t *telemetryMetaStore) getRelatedValues(ctx context.Context, orgID valuer.
 }
 
 func (t *telemetryMetaStore) GetRelatedValues(ctx context.Context, orgID valuer.UUID, fieldValueSelector *telemetrytypes.FieldValueSelector) ([]string, bool, error) {
-	return t.getRelatedValues(ctx, orgID, fieldValueSelector)
+	selectors := fieldValueSelector.NameMatchSelectors()
+	if len(selectors) == 1 {
+		return t.getRelatedValues(ctx, orgID, fieldValueSelector)
+	}
+
+	all := make([]*telemetrytypes.TelemetryFieldValues, 0, len(selectors))
+	complete := true
+	for _, selector := range selectors {
+		values, selectorComplete, err := t.getRelatedValues(ctx, orgID, selector)
+		if err != nil {
+			return nil, false, err
+		}
+		all = append(all, &telemetrytypes.TelemetryFieldValues{RelatedValues: values})
+		complete = complete && selectorComplete
+	}
+
+	merged, mergeComplete := mergeFieldValues(fieldValueSelector.Limit, all...)
+	return merged.RelatedValues, complete && mergeComplete, nil
 }
 
 func (t *telemetryMetaStore) getSpanFieldValues(ctx context.Context, orgID valuer.UUID, fieldValueSelector *telemetrytypes.FieldValueSelector) (*telemetrytypes.TelemetryFieldValues, bool, error) {
@@ -1826,7 +1845,7 @@ func (t *telemetryMetaStore) getMetricFieldValues(ctx context.Context, orgID val
 	}
 
 	if fieldValueSelector.FieldContext != telemetrytypes.FieldContextUnspecified {
-		sb.Where(sb.E("attr_type", fieldValueSelector.FieldContext.TagType()))
+		sb.Where(sb.E("attr_type", fieldValueSelector.FieldContext.MetricAttrType()))
 	}
 
 	if fieldValueSelector.FieldDataType != telemetrytypes.FieldDataTypeUnspecified {
@@ -2092,6 +2111,23 @@ func (t *telemetryMetaStore) getMeterSourceMetricFieldValues(ctx context.Context
 	return values, complete, nil
 }
 
+// mergeFieldValues dedupes the values into one result capped at limit, and reports
+// false when the cap dropped any.
+func mergeFieldValues(limit int, values ...*telemetrytypes.TelemetryFieldValues) (*telemetrytypes.TelemetryFieldValues, bool) {
+	if limit == 0 {
+		limit = 50
+	}
+
+	merged := &telemetrytypes.TelemetryFieldValues{}
+	mapOfValues := make(map[any]bool)
+	mapOfRelatedValues := make(map[any]bool)
+	complete := true
+	for _, v := range values {
+		complete = populateAllUnspecifiedValues(merged, mapOfValues, mapOfRelatedValues, v, limit) && complete
+	}
+	return merged, complete
+}
+
 func populateAllUnspecifiedValues(allUnspecifiedValues *telemetrytypes.TelemetryFieldValues, mapOfValues map[any]bool, mapOfRelatedValues map[any]bool, values *telemetrytypes.TelemetryFieldValues, limit int) bool {
 	complete := true
 	totalCount := len(mapOfValues) + len(mapOfRelatedValues)
@@ -2149,6 +2185,27 @@ func populateAllUnspecifiedValues(allUnspecifiedValues *telemetrytypes.Telemetry
 
 // GetAllValues returns all values and whether the result is complete.
 func (t *telemetryMetaStore) GetAllValues(ctx context.Context, orgID valuer.UUID, fieldValueSelector *telemetrytypes.FieldValueSelector) (*telemetrytypes.TelemetryFieldValues, bool, error) {
+	selectors := fieldValueSelector.NameMatchSelectors()
+	if len(selectors) == 1 {
+		return t.getAllValues(ctx, orgID, fieldValueSelector)
+	}
+
+	all := make([]*telemetrytypes.TelemetryFieldValues, 0, len(selectors))
+	complete := true
+	for _, selector := range selectors {
+		values, selectorComplete, err := t.getAllValues(ctx, orgID, selector)
+		if err != nil {
+			return nil, false, err
+		}
+		all = append(all, values)
+		complete = complete && selectorComplete
+	}
+
+	merged, mergeComplete := mergeFieldValues(fieldValueSelector.Limit, all...)
+	return merged, complete && mergeComplete, nil
+}
+
+func (t *telemetryMetaStore) getAllValues(ctx context.Context, orgID valuer.UUID, fieldValueSelector *telemetrytypes.FieldValueSelector) (*telemetrytypes.TelemetryFieldValues, bool, error) {
 	values := &telemetrytypes.TelemetryFieldValues{}
 	var complete = true
 	var err error

pkg/types/telemetrytypes/field.go

@@ -147,7 +147,11 @@ func (f *TelemetryFieldKey) Equal(key *TelemetryFieldKey) bool {
 //	key.Normalize()
 //	// Result: Name: "service.name", FieldContext: FieldContextResource, FieldDataType: FieldDataTypeString
 func (f *TelemetryFieldKey) Normalize() {
+	f.normalizeDataType()
+	f.normalizeContext()
+}
 
+func (f *TelemetryFieldKey) normalizeDataType() {
 	// Step 1: Parse data type from the right (after the last ":") if not already specified
 	if f.FieldDataType == FieldDataTypeUnspecified {
 		if colonIdx := strings.LastIndex(f.Name, ":"); colonIdx != -1 {
@@ -158,7 +162,9 @@ func (f *TelemetryFieldKey) Normalize() {
 			}
 		}
 	}
+}
 
+func (f *TelemetryFieldKey) normalizeContext() {
 	// Step 2: Parse field context from the left if not already specified
 	if f.FieldContext == FieldContextUnspecified {
 		if dotIdx := strings.Index(f.Name, "."); dotIdx != -1 {
@@ -279,6 +285,9 @@ type FieldValueSelector struct {
 	ExistingQuery string `json:"existingQuery" description:"Filter expression already applied in the explorer. Used to compute relatedValues; empty disables them."`
 	Value         string `json:"value" description:"Substring the returned values must contain, case-insensitive except for the meter source, where it is case-sensitive and % and _ act as wildcards. Empty returns any value."`
 	Limit         int    `json:"limit" description:"Maximum number of values to return."`
+
+	// nameAsWritten is set when FieldContext was parsed from the name's prefix.
+	nameAsWritten string
 }
 
 type GettableFieldKeys struct {
@@ -306,7 +315,7 @@ type GettableFieldValues struct {
 
 type PostableFieldValueParams struct {
 	PostableFieldKeysParams
-	Name          string `query:"name" description:"The key whose values to return, such as service.name. A context prefix such as resource.service.name sets fieldContext when it is empty."`
+	Name          string `query:"name" description:"The key whose values to return, such as service.name. With fieldContext set, it is the stored name as is. Otherwise a context prefix such as resource.service.name sets the context and a type suffix such as service.name:string sets fieldDataType when that is empty; as in filter expressions, a prefixed name other than resource. also matches a key stored under the full name, whose values come first: log.level returns values of a key named log.level, then of the log field level."`
 	ExistingQuery string `query:"existingQuery" description:"Filter expression already applied in the explorer. When set, relatedValues lists the values seen on data matching it."`
 }
 
@@ -358,26 +367,36 @@ func NewFieldKeySelectorFromPostableFieldKeysParams(params PostableFieldKeysPara
 }
 
 func NewFieldValueSelectorFromPostableFieldValueParams(params PostableFieldValueParams) *FieldValueSelector {
-
-	keySelector := NewFieldKeySelectorFromPostableFieldKeysParams(params.PostableFieldKeysParams)
+	// SearchText filters values here, so it must not be parsed as a key.
+	keyParams := params.PostableFieldKeysParams
+	keyParams.SearchText = ""
+	keySelector := NewFieldKeySelectorFromPostableFieldKeysParams(keyParams)
 
 	fieldValueSelector := &FieldValueSelector{
 		FieldKeySelector: keySelector,
 	}
 
-	fieldValueSelector.Name = params.Name
-
-	if params.Name != "" && fieldValueSelector.FieldContext == FieldContextUnspecified {
-		parsedFieldKey := GetFieldKeyFromKeyText(params.Name)
-		if parsedFieldKey.FieldContext != FieldContextUnspecified {
-			// Only apply inferred context if it is valid for the current signal
-			if isContextValidForSignal(parsedFieldKey.FieldContext, fieldValueSelector.Signal) {
-				fieldValueSelector.Name = parsedFieldKey.Name
-				fieldValueSelector.FieldContext = parsedFieldKey.FieldContext
+	// An explicit context means the name is the stored name as is.
+	key := TelemetryFieldKey{Name: params.Name, FieldContext: keySelector.FieldContext, FieldDataType: keySelector.FieldDataType}
+	if keySelector.FieldContext == FieldContextUnspecified {
+		key.normalizeDataType()
+		nameWithContext := key.Name
+		key.normalizeContext()
+		// Only apply inferred context if it is valid for the current signal
+		if isContextValidForSignal(key.FieldContext, keySelector.Signal) {
+			// resource is a keyword prefix, never part of a stored name.
+			if key.FieldContext != FieldContextUnspecified && key.FieldContext != FieldContextResource {
+				fieldValueSelector.nameAsWritten = nameWithContext
 			}
+		} else {
+			key.Name = nameWithContext
+			key.FieldContext = FieldContextUnspecified
 		}
 	}
 
+	fieldValueSelector.Name = key.Name
+	fieldValueSelector.FieldContext = key.FieldContext
+	fieldValueSelector.FieldDataType = key.FieldDataType
 	fieldValueSelector.ExistingQuery = params.ExistingQuery
 	fieldValueSelector.Value = params.SearchText
 
@@ -390,6 +409,29 @@ func NewFieldValueSelectorFromPostableFieldValueParams(params PostableFieldValue
 	return fieldValueSelector
 }
 
+// NameMatchSelectors returns the lookups for the requested key, highest priority first.
+// A context parsed from the name may instead be part of the stored name (attribute.key
+// may be the attribute named attribute.key), so like the query builder both readings are
+// looked up: the name as written, in any context, before the name with its prefix stripped.
+func (s *FieldValueSelector) NameMatchSelectors() []*FieldValueSelector {
+	if s.nameAsWritten != "" {
+		return []*FieldValueSelector{s.withName(s.nameAsWritten), s}
+	}
+	return []*FieldValueSelector{s}
+}
+
+// withName returns a copy looking up name in any context.
+func (s *FieldValueSelector) withName(name string) *FieldValueSelector {
+	keySelector := *s.FieldKeySelector
+	keySelector.Name = name
+	keySelector.FieldContext = FieldContextUnspecified
+
+	selector := *s
+	selector.FieldKeySelector = &keySelector
+	selector.nameAsWritten = ""
+	return &selector
+}
+
 func NewTelemetryFieldKey(name string, fieldContext FieldContext, fieldDataType FieldDataType) *TelemetryFieldKey {
 	return &TelemetryFieldKey{
 		Name:          name,

pkg/types/telemetrytypes/field_context.go

@@ -164,6 +164,15 @@ func (f FieldContext) TagType() string {
 	return ""
 }
 
+// MetricAttrType returns the attr_type the metrics metadata table stores for the context;
+// metric attributes are stored as point.
+func (f FieldContext) MetricAttrType() string {
+	if f == FieldContextAttribute {
+		return "point"
+	}
+	return f.TagType()
+}
+
 func isContextValidForSignal(ctx FieldContext, signal Signal) bool {
 	if ctx == FieldContextResource ||
 		ctx == FieldContextAttribute ||

pkg/types/telemetrytypes/field_context_test.go

@@ -0,0 +1,25 @@
+package telemetrytypes
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFieldContextMetricAttrType(t *testing.T) {
+	testCases := []struct {
+		name     string
+		context  FieldContext
+		expected string
+	}{
+		{name: "Attribute_Point", context: FieldContextAttribute, expected: "point"},
+		{name: "Resource_Resource", context: FieldContextResource, expected: "resource"},
+		{name: "Scope_Scope", context: FieldContextScope, expected: "scope"},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			assert.Equal(t, testCase.expected, testCase.context.MetricAttrType())
+		})
+	}
+}

pkg/types/telemetrytypes/field_test.go

@@ -3,6 +3,9 @@ package telemetrytypes
 import (
 	"reflect"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestGetFieldKeyFromKeyText(t *testing.T) {
@@ -422,3 +425,168 @@ func TestNewFieldKeySelectorFromPostableFieldKeysParamsMetricNamespace(t *testin
 		t.Fatalf("expected metric name to remain empty, got %q", selector.MetricContext.MetricName)
 	}
 }
+
+func TestNewFieldValueSelectorFromPostableFieldValueParams(t *testing.T) {
+	testCases := []struct {
+		name             string
+		params           PostableFieldValueParams
+		expectedName     string
+		expectedContext  FieldContext
+		expectedDataType FieldDataType
+		expectedValue    string
+		expectedLookups  []TelemetryFieldKey
+	}{
+		{
+			name:            "ResourcePrefix_AlwaysContext_SingleLookup",
+			params:          PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs}, Name: "resource.service.name"},
+			expectedName:    "service.name",
+			expectedContext: FieldContextResource,
+			expectedLookups: []TelemetryFieldKey{{Name: "service.name", FieldContext: FieldContextResource}},
+		},
+		{
+			name:            "AttributePrefix_Parsed",
+			params:          PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs}, Name: "attribute.key"},
+			expectedName:    "key",
+			expectedContext: FieldContextAttribute,
+			expectedLookups: []TelemetryFieldKey{{Name: "attribute.key", FieldContext: FieldContextUnspecified}, {Name: "key", FieldContext: FieldContextAttribute}},
+		},
+		{
+			name:            "DoubleAttributePrefix_OnlyFirstStripped",
+			params:          PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs}, Name: "attribute.attribute.key"},
+			expectedName:    "attribute.key",
+			expectedContext: FieldContextAttribute,
+			expectedLookups: []TelemetryFieldKey{{Name: "attribute.attribute.key", FieldContext: FieldContextUnspecified}, {Name: "attribute.key", FieldContext: FieldContextAttribute}},
+		},
+		{
+			name:            "TagAlias_ExactMatchAsWritten",
+			params:          PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs}, Name: "tag.region"},
+			expectedName:    "region",
+			expectedContext: FieldContextAttribute,
+			expectedLookups: []TelemetryFieldKey{{Name: "tag.region", FieldContext: FieldContextUnspecified}, {Name: "region", FieldContext: FieldContextAttribute}},
+		},
+		{
+			name:            "LogPrefix_Parsed",
+			params:          PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs}, Name: "log.level"},
+			expectedName:    "level",
+			expectedContext: FieldContextLog,
+			expectedLookups: []TelemetryFieldKey{{Name: "log.level", FieldContext: FieldContextUnspecified}, {Name: "level", FieldContext: FieldContextLog}},
+		},
+		{
+			name:            "SpanPrefix_Parsed",
+			params:          PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalTraces}, Name: "span.kind"},
+			expectedName:    "kind",
+			expectedContext: FieldContextSpan,
+			expectedLookups: []TelemetryFieldKey{{Name: "span.kind", FieldContext: FieldContextUnspecified}, {Name: "kind", FieldContext: FieldContextSpan}},
+		},
+		{
+			name:            "ContextInvalidForSignal_KeptAsWritten",
+			params:          PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs}, Name: "span.kind"},
+			expectedName:    "span.kind",
+			expectedContext: FieldContextUnspecified,
+			expectedLookups: []TelemetryFieldKey{{Name: "span.kind", FieldContext: FieldContextUnspecified}},
+		},
+		{
+			name:            "ExplicitContext_NameNotParsed",
+			params:          PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs, FieldContext: FieldContextAttribute}, Name: "log.level"},
+			expectedName:    "log.level",
+			expectedContext: FieldContextAttribute,
+			expectedLookups: []TelemetryFieldKey{{Name: "log.level", FieldContext: FieldContextAttribute}},
+		},
+		{
+			name:            "ExplicitBodyContext_SingleLookup",
+			params:          PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs, FieldContext: FieldContextBody}, Name: "key"},
+			expectedName:    "key",
+			expectedContext: FieldContextBody,
+			expectedLookups: []TelemetryFieldKey{{Name: "key", FieldContext: FieldContextBody}},
+		},
+		{
+			name:            "ExplicitAttributeContext_SingleLookup",
+			params:          PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs, FieldContext: FieldContextAttribute}, Name: "key"},
+			expectedName:    "key",
+			expectedContext: FieldContextAttribute,
+			expectedLookups: []TelemetryFieldKey{{Name: "key", FieldContext: FieldContextAttribute}},
+		},
+		{
+			name:            "ExplicitAttributeContext_PrefixedStoredName",
+			params:          PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs, FieldContext: FieldContextAttribute}, Name: "attribute.key"},
+			expectedName:    "attribute.key",
+			expectedContext: FieldContextAttribute,
+			expectedLookups: []TelemetryFieldKey{{Name: "attribute.key", FieldContext: FieldContextAttribute}},
+		},
+		{
+			name:            "ExplicitContext_TypeSuffixNotParsed",
+			params:          PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs, FieldContext: FieldContextAttribute}, Name: "http.method:string"},
+			expectedName:    "http.method:string",
+			expectedContext: FieldContextAttribute,
+			expectedLookups: []TelemetryFieldKey{{Name: "http.method:string", FieldContext: FieldContextAttribute}},
+		},
+		{
+			name:             "DataTypeSuffix_WithoutContext",
+			params:           PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs}, Name: "service.name:string"},
+			expectedName:     "service.name",
+			expectedContext:  FieldContextUnspecified,
+			expectedDataType: FieldDataTypeString,
+			expectedLookups:  []TelemetryFieldKey{{Name: "service.name", FieldContext: FieldContextUnspecified}},
+		},
+		{
+			name:             "DataTypeSuffix_WithContext",
+			params:           PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs}, Name: "resource.host.name:string"},
+			expectedName:     "host.name",
+			expectedContext:  FieldContextResource,
+			expectedDataType: FieldDataTypeString,
+			expectedLookups:  []TelemetryFieldKey{{Name: "host.name", FieldContext: FieldContextResource}},
+		},
+		{
+			name:             "DataTypeSuffix_WithInvalidContext",
+			params:           PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs}, Name: "span.kind:int64"},
+			expectedName:     "span.kind",
+			expectedContext:  FieldContextUnspecified,
+			expectedDataType: FieldDataTypeInt64,
+			expectedLookups:  []TelemetryFieldKey{{Name: "span.kind", FieldContext: FieldContextUnspecified}},
+		},
+		{
+			name:             "ExplicitDataType_SuffixKept",
+			params:           PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs, FieldDataType: FieldDataTypeBool}, Name: "http.method:string"},
+			expectedName:     "http.method:string",
+			expectedContext:  FieldContextUnspecified,
+			expectedDataType: FieldDataTypeBool,
+			expectedLookups:  []TelemetryFieldKey{{Name: "http.method:string", FieldContext: FieldContextUnspecified}},
+		},
+		{
+			name:            "SearchTextWithContextPrefix_NotParsedAsKey",
+			params:          PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs, SearchText: "log.x"}, Name: "service.name"},
+			expectedName:    "service.name",
+			expectedContext: FieldContextUnspecified,
+			expectedValue:   "log.x",
+			expectedLookups: []TelemetryFieldKey{{Name: "service.name", FieldContext: FieldContextUnspecified}},
+		},
+		{
+			name:            "SearchTextWithContextPrefix_NameStillParsed",
+			params:          PostableFieldValueParams{PostableFieldKeysParams: PostableFieldKeysParams{Signal: SignalLogs, SearchText: "attribute.x"}, Name: "resource.k8s.pod.name"},
+			expectedName:    "k8s.pod.name",
+			expectedContext: FieldContextResource,
+			expectedValue:   "attribute.x",
+			expectedLookups: []TelemetryFieldKey{{Name: "k8s.pod.name", FieldContext: FieldContextResource}},
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			selector := NewFieldValueSelectorFromPostableFieldValueParams(testCase.params)
+
+			assert.Equal(t, testCase.expectedName, selector.Name)
+			assert.Equal(t, testCase.expectedContext, selector.FieldContext)
+			assert.Equal(t, testCase.expectedDataType, selector.FieldDataType)
+			assert.Equal(t, testCase.expectedValue, selector.Value)
+
+			lookups := selector.NameMatchSelectors()
+			require.Len(t, lookups, len(testCase.expectedLookups))
+			for i, expected := range testCase.expectedLookups {
+				assert.Equal(t, expected.Name, lookups[i].Name)
+				assert.Equal(t, expected.FieldContext, lookups[i].FieldContext)
+				assert.Equal(t, selector.FieldDataType, lookups[i].FieldDataType)
+			}
+			assert.Equal(t, testCase.expectedName, selector.Name, "lookups must not mutate the selector")
+		})
+	}
+}

tests/integration/tests/queriermetrics/09_cost_meter.py

@@ -106,81 +106,3 @@ def test_list_meter_metric_names(
     metrics = data.get("data", {}).get("metrics", [])
     metric_names = [m["metricName"] for m in metrics]
     assert metric_name in metric_names, f"Expected {metric_name} in metric names, got: {metric_names}"
-
-
-# Verify /api/v1/fields/values with source=meter filters label values by metricNamespace
-# prefix. Inserts meter-source metrics under ns.a and ns.b, then asserts a specific
-# prefix returns only matching values while a common prefix returns both.
-def test_metric_namespace_meter_values_filtering(
-    signoz: types.SigNoz,
-    create_user_admin: None,  # pylint: disable=unused-argument
-    get_token: Callable[[str, str], str],
-    insert_meter_samples: Callable[[list[MeterSample]], None],
-) -> None:
-    now = datetime.now(tz=UTC).replace(second=0, microsecond=0)
-
-    samples_a = make_meter_samples(
-        "meter.ns.a.cost",
-        {"service": "billing-a"},
-        now,
-        count=5,
-        base_value=10.0,
-        temporality="Delta",
-        type_="Sum",
-        is_monotonic=True,
-    )
-    samples_b = make_meter_samples(
-        "meter.ns.b.cost",
-        {"service": "billing-b"},
-        now,
-        count=5,
-        base_value=20.0,
-        temporality="Delta",
-        type_="Sum",
-        is_monotonic=True,
-    )
-    insert_meter_samples(samples_a + samples_b)
-
-    token = get_token(USER_ADMIN_EMAIL, USER_ADMIN_PASSWORD)
-
-    # Specific prefix: metricNamespace=meter.ns.a should return only billing-a
-    response = requests.get(
-        signoz.self.host_configs["8080"].get("/api/v1/fields/values"),
-        timeout=5,
-        headers={"authorization": f"Bearer {token}"},
-        params={
-            "signal": "metrics",
-            "source": "meter",
-            "name": "service",
-            "searchText": "",
-            "metricNamespace": "meter.ns.a",
-        },
-    )
-
-    assert response.status_code == HTTPStatus.OK
-    assert response.json()["status"] == "success"
-
-    values = response.json()["data"]["values"]["stringValues"]
-    assert "billing-a" in values
-    assert "billing-b" not in values
-
-    # Common prefix: metricNamespace=meter.ns should return both
-    response = requests.get(
-        signoz.self.host_configs["8080"].get("/api/v1/fields/values"),
-        timeout=5,
-        headers={"authorization": f"Bearer {token}"},
-        params={
-            "signal": "metrics",
-            "source": "meter",
-            "name": "service",
-            "searchText": "",
-            "metricNamespace": "meter.ns",
-        },
-    )
-
-    assert response.status_code == HTTPStatus.OK
-    assert response.json()["status"] == "success"
-
-    values = response.json()["data"]["values"]["stringValues"]
-    assert "billing-a" in values
-    assert "billing-b" in values

tests/integration/tests/quickfilter/02_values_name_resolution.py

@@ -0,0 +1,96 @@
+from collections.abc import Callable
+from datetime import UTC, datetime
+from http import HTTPStatus
+
+import pytest
+
+from fixtures import types
+from fixtures.auth import USER_ADMIN_EMAIL, USER_ADMIN_PASSWORD
+from fixtures.logs import Logs
+from fixtures.metadata import get_field_values
+from fixtures.metrics import Metrics
+
+
+@pytest.mark.parametrize(
+    "params,expected,complete",
+    [
+        pytest.param({"name": "key"}, ["attr-plain"], True, id="unprefixed_name_matches_stored_name"),
+        pytest.param({"name": "attribute.key"}, ["attr-prefixed", "attr-plain"], True, id="prefixed_name_matches_exact_then_stripped"),
+        pytest.param({"name": "attribute.key", "limit": 1}, ["attr-prefixed"], False, id="exact_match_wins_the_limit"),
+        pytest.param({"name": "attribute.attribute.key"}, ["attr-prefixed"], True, id="double_prefix_reaches_prefixed_stored_name"),
+        pytest.param({"name": "log.severity_text"}, ["attr-severity", "WARN"], True, id="log_prefix_matches_attribute_then_log_field"),
+        pytest.param({"name": "resource.service.name"}, ["svc-resource"], True, id="resource_prefix_is_always_context"),
+        pytest.param({"name": "key", "fieldContext": "attribute"}, ["attr-plain"], True, id="explicit_context_single_lookup"),
+        pytest.param({"name": "attribute.key", "fieldContext": "attribute"}, ["attr-prefixed"], True, id="explicit_context_name_not_parsed"),
+        pytest.param({"name": "service.name:string"}, ["svc-resource"], True, id="type_suffix_without_context"),
+        pytest.param({"name": "path", "searchText": "log.arch"}, ["log.archive"], True, id="search_text_not_parsed_as_key"),
+        pytest.param({"name": "no_such_key"}, [], True, id="unknown_name_returns_no_values"),
+        pytest.param({"name": "attribute.no_such_key"}, [], True, id="unknown_prefixed_name_returns_no_values"),
+    ],
+)
+def test_fields_values_name_resolution(
+    signoz: types.SigNoz,
+    create_user_admin: None,  # pylint: disable=unused-argument
+    get_token: Callable[[str, str], str],
+    insert_logs: Callable[[list[Logs]], None],
+    params: dict,
+    expected: list[str],
+    complete: bool,
+) -> None:
+    """
+    Setup:
+    Insert a log whose attributes include names that start with a context word: attribute.key next
+    to key, log.severity_text next to the severity_text log field, and resource.service.name next to
+    the service.name resource.
+
+    Tests:
+    1. A name with a context prefix returns values of the name as written first, then of the name
+       with the prefix stripped; resource. is always a context.
+    2. An explicit fieldContext takes the name as is.
+    3. A :type suffix is stripped, and searchText filters values without being read as a key.
+    """
+    insert_logs(
+        [
+            Logs(
+                timestamp=datetime.now(tz=UTC),
+                resources={"service.name": "svc-resource"},
+                attributes={
+                    "key": "attr-plain",
+                    "attribute.key": "attr-prefixed",
+                    "log.severity_text": "attr-severity",
+                    "resource.service.name": "attr-resource",
+                    "path": "log.archive",
+                },
+                severity_text="WARN",
+            )
+        ]
+    )
+
+    token = get_token(USER_ADMIN_EMAIL, USER_ADMIN_PASSWORD)
+    response = get_field_values(signoz, token, {"signal": "logs", **params})
+
+    assert response.status_code == HTTPStatus.OK
+    assert response.json()["data"]["values"].get("stringValues", []) == expected
+    assert response.json()["data"]["complete"] is complete
+
+
+def test_fields_values_metric_attribute_context(
+    signoz: types.SigNoz,
+    create_user_admin: None,  # pylint: disable=unused-argument
+    get_token: Callable[[str, str], str],
+    insert_metrics: Callable[[list[Metrics]], None],
+) -> None:
+    """
+    Setup:
+    Insert a metric with a service label, stored with attr_type point.
+
+    Tests:
+    1. fieldContext=attribute returns the label's values.
+    """
+    insert_metrics([Metrics(metric_name="fields.requests_total", labels={"service": "svc-metric"}, value=1.0)])
+
+    token = get_token(USER_ADMIN_EMAIL, USER_ADMIN_PASSWORD)
+    response = get_field_values(signoz, token, {"signal": "metrics", "name": "service", "fieldContext": "attribute"})
+
+    assert response.status_code == HTTPStatus.OK
+    assert response.json()["data"]["values"]["stringValues"] == ["svc-metric"]

tests/integration/tests/quickfilter/03_related_values_name_resolution.py

@@ -0,0 +1,126 @@
+from collections.abc import Callable
+from datetime import UTC, datetime
+from http import HTTPStatus
+
+import pytest
+
+from fixtures import types
+from fixtures.auth import USER_ADMIN_EMAIL, USER_ADMIN_PASSWORD
+from fixtures.logs import Logs
+from fixtures.metadata import AttributesMetadata, get_field_values
+
+
+@pytest.mark.parametrize(
+    "params,expected,complete",
+    [
+        pytest.param({"name": "key"}, ["rel-plain"], True, id="unprefixed_name_matches_stored_name"),
+        pytest.param({"name": "attribute.key"}, ["rel-prefixed", "rel-plain"], True, id="prefixed_name_matches_exact_then_stripped"),
+        pytest.param({"name": "attribute.key", "limit": 1}, ["rel-prefixed"], False, id="exact_match_wins_the_limit"),
+        pytest.param({"name": "attribute.key", "searchText": "plain"}, ["rel-plain"], True, id="search_text_filters_both_lookups"),
+        pytest.param({"name": "attribute.attribute.key"}, ["rel-prefixed"], True, id="double_prefix_reaches_prefixed_stored_name"),
+        pytest.param({"name": "resource.region"}, ["rel-region"], True, id="resource_prefix_is_always_context"),
+        pytest.param({"name": "key", "fieldContext": "attribute"}, ["rel-plain"], True, id="explicit_context_single_lookup"),
+        pytest.param({"name": "attribute.key", "fieldContext": "attribute"}, ["rel-prefixed"], True, id="explicit_context_name_not_parsed"),
+    ],
+)
+def test_related_values_name_resolution(
+    signoz: types.SigNoz,
+    create_user_admin: None,  # pylint: disable=unused-argument
+    get_token: Callable[[str, str], str],
+    insert_logs: Callable[[list[Logs]], None],
+    insert_attributes_metadata: Callable[[list[AttributesMetadata]], None],
+    params: dict,
+    expected: list[str],
+    complete: bool,
+) -> None:
+    """
+    Setup:
+    Insert attributes_metadata rows for logs carrying key and attribute.key on service svc-rel, the
+    same keys on svc-other, and an attribute named resource.region next to a region resource.
+    A log registers service.name so existingQuery can resolve it.
+
+    Tests:
+    1. Related values resolve the name like all values: name as written first, then the prefix
+       stripped; resource. is always a context and an explicit fieldContext takes the name as is.
+    2. Rows outside existingQuery never surface.
+    """
+    now = datetime.now(tz=UTC)
+    insert_logs([Logs(timestamp=now, resources={"service.name": "svc-registration"}, body="registers service.name")])
+    insert_attributes_metadata(
+        [
+            AttributesMetadata(data_source="logs", resource_attributes={"service.name": "svc-rel"}, attributes={"key": "rel-plain"}, timestamp=now),
+            AttributesMetadata(data_source="logs", resource_attributes={"service.name": "svc-rel"}, attributes={"attribute.key": "rel-prefixed"}, timestamp=now),
+            AttributesMetadata(
+                data_source="logs",
+                resource_attributes={"service.name": "svc-rel", "region": "rel-region"},
+                attributes={"resource.region": "rel-attr-region"},
+                timestamp=now,
+            ),
+            AttributesMetadata(
+                data_source="logs",
+                resource_attributes={"service.name": "svc-other"},
+                attributes={"key": "other-plain", "attribute.key": "other-prefixed"},
+                timestamp=now,
+            ),
+        ]
+    )
+
+    token = get_token(USER_ADMIN_EMAIL, USER_ADMIN_PASSWORD)
+    response = get_field_values(signoz, token, {"signal": "logs", "existingQuery": "service.name = 'svc-rel'", **params})
+
+    assert response.status_code == HTTPStatus.OK
+    assert response.json()["data"]["values"].get("relatedValues") == expected
+    assert response.json()["data"]["complete"] is complete
+
+
+@pytest.mark.parametrize(
+    "name,existing_query,expected",
+    [
+        pytest.param("no_such_key", "service.name = 'svc-a'", set(), id="unknown_name_returns_no_values"),
+        pytest.param("key", "service.name = 'svc-a'", {"rel-a"}, id="known_filter_key_filters"),
+        pytest.param("key", "no_such_filter = 'x'", {"rel-a", "rel-b"}, id="unknown_key_equal_drops_filter"),
+        pytest.param("key", "service.name = 'svc-a' AND no_such_filter = 'x'", {"rel-a"}, id="unknown_key_equal_dropped_from_and"),
+        pytest.param("key", "service.name = 'svc-a' OR no_such_filter = 'x'", {"rel-a", "rel-b"}, id="unknown_key_equal_drops_whole_or"),
+        pytest.param("key", "no_such_filter != 'x'", {"rel-a", "rel-b"}, id="unknown_key_not_equal_drops_filter"),
+        pytest.param("key", "service.name = 'svc-a' AND no_such_filter != 'x'", {"rel-a"}, id="unknown_key_not_equal_dropped_from_and"),
+        pytest.param("key", "service.name = 'svc-a' OR no_such_filter != 'x'", {"rel-a", "rel-b"}, id="unknown_key_not_equal_drops_whole_or"),
+        pytest.param("key", "NOT no_such_filter = 'x'", {"rel-a", "rel-b"}, id="not_over_unknown_key_drops_filter"),
+        pytest.param("key", "service.name = 'svc-a' AND NOT no_such_filter = 'x'", {"rel-a"}, id="not_over_unknown_key_dropped_from_and"),
+        pytest.param("key", "no_such_filter NOT EXISTS", {"rel-a", "rel-b"}, id="unknown_key_not_exists_drops_filter"),
+    ],
+)
+def test_related_values_unknown_keys(
+    signoz: types.SigNoz,
+    create_user_admin: None,  # pylint: disable=unused-argument
+    get_token: Callable[[str, str], str],
+    insert_logs: Callable[[list[Logs]], None],
+    insert_attributes_metadata: Callable[[list[AttributesMetadata]], None],
+    name: str,
+    existing_query: str,
+    expected: set[str],
+) -> None:
+    """
+    Setup:
+    Insert attributes_metadata rows for logs with key on svc-a and on svc-b. A log registers
+    service.name so existingQuery can resolve it.
+
+    Tests:
+    1. An unknown name returns no values and no error.
+    2. A term on an unknown key is dropped whatever its operator, and NOT does not flip it: it reads
+       as true, so it vanishes from an AND and drops the whole OR.
+    """
+    now = datetime.now(tz=UTC)
+    insert_logs([Logs(timestamp=now, resources={"service.name": "svc-registration"}, body="registers service.name")])
+    insert_attributes_metadata(
+        [
+            AttributesMetadata(data_source="logs", resource_attributes={"service.name": "svc-a"}, attributes={"key": "rel-a"}, timestamp=now),
+            AttributesMetadata(data_source="logs", resource_attributes={"service.name": "svc-b"}, attributes={"key": "rel-b"}, timestamp=now),
+        ]
+    )
+
+    token = get_token(USER_ADMIN_EMAIL, USER_ADMIN_PASSWORD)
+    response = get_field_values(signoz, token, {"signal": "logs", "name": name, "existingQuery": existing_query})
+
+    assert response.status_code == HTTPStatus.OK
+    assert set(response.json()["data"]["values"].get("relatedValues") or []) == expected
+    assert response.json()["data"]["complete"] is True

tests/integration/tests/quickfilter/04_keys_name_resolution.py

@@ -0,0 +1,68 @@
+from collections.abc import Callable
+from datetime import UTC, datetime
+from http import HTTPStatus
+
+import pytest
+
+from fixtures import types
+from fixtures.auth import USER_ADMIN_EMAIL, USER_ADMIN_PASSWORD
+from fixtures.logs import Logs
+from fixtures.metadata import get_field_keys
+
+
+@pytest.mark.parametrize(
+    "params,present,absent",
+    [
+        pytest.param({"searchText": "key"}, {"key": "attribute", "attribute.key": "attribute"}, ["severity_text"], id="unprefixed_search_matches_names_containing_it"),
+        pytest.param({"searchText": "attribute.key"}, {"key": "attribute", "attribute.key": "attribute"}, ["service.name"], id="attribute_prefix_sets_context"),
+        pytest.param({"searchText": "attribute.attribute"}, {"attribute.key": "attribute"}, ["key"], id="double_prefix_searches_prefixed_stored_name"),
+        pytest.param({"searchText": "attribute.key", "fieldContext": "attribute"}, {"attribute.key": "attribute"}, ["key"], id="explicit_context_search_not_parsed"),
+        pytest.param({"searchText": "resource.service"}, {"service.name": "resource"}, ["resource.service.name"], id="resource_prefix_is_always_context"),
+        pytest.param({"searchText": "log.severity"}, {"severity_text": "log"}, ["log.severity_text"], id="log_prefix_searches_log_context_only"),
+        pytest.param({"searchText": "span.kind"}, {"span.kind": "attribute"}, ["kind"], id="context_invalid_for_signal_kept_in_search"),
+    ],
+)
+def test_fields_keys_name_resolution(
+    signoz: types.SigNoz,
+    create_user_admin: None,  # pylint: disable=unused-argument
+    get_token: Callable[[str, str], str],
+    insert_logs: Callable[[list[Logs]], None],
+    params: dict,
+    present: dict[str, str],
+    absent: list[str],
+) -> None:
+    """
+    Setup:
+    Insert a log whose attributes include names that start with a context word: attribute.key next
+    to key, log.severity_text next to the severity_text log field, and resource.service.name next to
+    the service.name resource.
+
+    Tests:
+    1. A context prefix in searchText that is valid for the signal sets the context and is searched
+       without it; an explicit fieldContext searches the text as is.
+    2. Keys search stays within that context, so prefixed stored names in another context are not listed.
+    """
+    insert_logs(
+        [
+            Logs(
+                timestamp=datetime.now(tz=UTC),
+                resources={"service.name": "svc-resource"},
+                attributes={
+                    "key": "attr-plain",
+                    "attribute.key": "attr-prefixed",
+                    "log.severity_text": "attr-severity",
+                    "resource.service.name": "attr-resource",
+                    "span.kind": "attr-kind",
+                },
+                severity_text="WARN",
+            )
+        ]
+    )
+
+    token = get_token(USER_ADMIN_EMAIL, USER_ADMIN_PASSWORD)
+    response = get_field_keys(signoz, token, {"signal": "logs", **params})
+
+    assert response.status_code == HTTPStatus.OK
+    keys = response.json()["data"]["keys"]
+    assert {name: [key["fieldContext"] for key in keys.get(name, [])] for name in present} == {name: [context] for name, context in present.items()}
+    assert [name for name in absent if name in keys] == []

tests/integration/tests/quickfilter/06_related_values.py

@@ -15,13 +15,13 @@ from fixtures.traces import Traces
 
 # Related values (/api/v1/fields/values with existingQuery) are served from the
 # shared signoz_metadata.attributes_metadata table, scoped by data_source =
-# signal. One dataset (queriercommon/related_values.jsonl) drives every scenario:
+# signal. One dataset (quickfilter/related_values.jsonl) drives every scenario:
 #   - Filter attributes (namespace/statefulset/cluster) are identical across
 #     data_sources, so the same existingQuery matches under any signal.
 #   - Target values (k8s.pod.name / host.name) are suffixed per data_source, so
 #     the returned set differs by signal -> every scenario also proves the
 #     data_source scoping (no cross-signal leakage).
-DATASET = "queriercommon/related_values.jsonl"
+DATASET = "quickfilter/related_values.jsonl"
 
 
 @pytest.fixture(name="seed_related_values", scope="function")

tests/integration/tests/quickfilter/08_meter_values.py

@@ -0,0 +1,87 @@
+from collections.abc import Callable
+from datetime import UTC, datetime
+from http import HTTPStatus
+
+import requests
+
+from fixtures import types
+from fixtures.auth import USER_ADMIN_EMAIL, USER_ADMIN_PASSWORD
+from fixtures.meter import MeterSample, make_meter_samples
+
+
+# Verify /api/v1/fields/values with source=meter filters label values by metricNamespace
+# prefix. Inserts meter-source metrics under ns.a and ns.b, then asserts a specific
+# prefix returns only matching values while a common prefix returns both.
+def test_metric_namespace_meter_values_filtering(
+    signoz: types.SigNoz,
+    create_user_admin: None,  # pylint: disable=unused-argument
+    get_token: Callable[[str, str], str],
+    insert_meter_samples: Callable[[list[MeterSample]], None],
+) -> None:
+    now = datetime.now(tz=UTC).replace(second=0, microsecond=0)
+
+    samples_a = make_meter_samples(
+        "meter.ns.a.cost",
+        {"service": "billing-a"},
+        now,
+        count=5,
+        base_value=10.0,
+        temporality="Delta",
+        type_="Sum",
+        is_monotonic=True,
+    )
+    samples_b = make_meter_samples(
+        "meter.ns.b.cost",
+        {"service": "billing-b"},
+        now,
+        count=5,
+        base_value=20.0,
+        temporality="Delta",
+        type_="Sum",
+        is_monotonic=True,
+    )
+    insert_meter_samples(samples_a + samples_b)
+
+    token = get_token(USER_ADMIN_EMAIL, USER_ADMIN_PASSWORD)
+
+    # Specific prefix: metricNamespace=meter.ns.a should return only billing-a
+    response = requests.get(
+        signoz.self.host_configs["8080"].get("/api/v1/fields/values"),
+        timeout=5,
+        headers={"authorization": f"Bearer {token}"},
+        params={
+            "signal": "metrics",
+            "source": "meter",
+            "name": "service",
+            "searchText": "",
+            "metricNamespace": "meter.ns.a",
+        },
+    )
+
+    assert response.status_code == HTTPStatus.OK
+    assert response.json()["status"] == "success"
+
+    values = response.json()["data"]["values"]["stringValues"]
+    assert "billing-a" in values
+    assert "billing-b" not in values
+
+    # Common prefix: metricNamespace=meter.ns should return both
+    response = requests.get(
+        signoz.self.host_configs["8080"].get("/api/v1/fields/values"),
+        timeout=5,
+        headers={"authorization": f"Bearer {token}"},
+        params={
+            "signal": "metrics",
+            "source": "meter",
+            "name": "service",
+            "searchText": "",
+            "metricNamespace": "meter.ns",
+        },
+    )
+
+    assert response.status_code == HTTPStatus.OK
+    assert response.json()["status"] == "success"
+
+    values = response.json()["data"]["values"]["stringValues"]
+    assert "billing-a" in values
+    assert "billing-b" in values