diff --git a/app/vmselect/promql/aggr.go b/app/vmselect/promql/aggr.go
index 4cf01c5ff..e6caeec06 100644
--- a/app/vmselect/promql/aggr.go
+++ b/app/vmselect/promql/aggr.go
@@ -86,7 +86,7 @@ func removeGroupTags(metricName *storage.MetricName, modifier *metricsql.Modifie
 }
 
 func aggrFuncExt(afe func(tss []*timeseries) []*timeseries, argOrig []*timeseries, modifier *metricsql.ModifierExpr, maxSeries int, keepOriginal bool) ([]*timeseries, error) {
-	arg := copyTimeseriesMetricNames(argOrig)
+	arg := copyTimeseriesMetricNames(argOrig, keepOriginal)
 
 	// Perform grouping.
 	m := make(map[string][]*timeseries)
diff --git a/app/vmselect/promql/aggr_incremental.go b/app/vmselect/promql/aggr_incremental.go
index c9d058b3e..1321ca73c 100644
--- a/app/vmselect/promql/aggr_incremental.go
+++ b/app/vmselect/promql/aggr_incremental.go
@@ -52,6 +52,13 @@ var incrementalAggrFuncCallbacksMap = map[string]*incrementalAggrFuncCallbacks{
 		updateAggrFunc:   updateAggrAny,
 		mergeAggrFunc:    mergeAggrAny,
 		finalizeAggrFunc: finalizeAggrCommon,
+
+		keepOriginal: true,
+	},
+	"group": {
+		updateAggrFunc:   updateAggrGroup,
+		mergeAggrFunc:    mergeAggrAny,
+		finalizeAggrFunc: finalizeAggrCommon,
 	},
 }
 
@@ -72,7 +79,7 @@ func newIncrementalAggrFuncContext(ae *metricsql.AggrFuncExpr, callbacks *increm
 	}
 }
 
-func (iafc *incrementalAggrFuncContext) updateTimeseries(ts *timeseries, workerID uint) {
+func (iafc *incrementalAggrFuncContext) updateTimeseries(tsOrig *timeseries, workerID uint) {
 	iafc.mLock.Lock()
 	m := iafc.m[workerID]
 	if m == nil {
@@ -81,6 +88,13 @@ func (iafc *incrementalAggrFuncContext) updateTimeseries(ts *timeseries, workerI
 	}
 	iafc.mLock.Unlock()
 
+	ts := tsOrig
+	keepOriginal := iafc.callbacks.keepOriginal
+	if keepOriginal {
+		var dst timeseries
+		dst.CopyFromMetricNames(tsOrig)
+		ts = &dst
+	}
 	removeGroupTags(&ts.MetricName, &iafc.ae.Modifier)
 	bb := bbPool.Get()
 	bb.B = marshalMetricNameSorted(bb.B[:0], &ts.MetricName)
@@ -95,6 +109,9 @@ func (iafc *incrementalAggrFuncContext) updateTimeseries(ts *timeseries, workerI
 			Timestamps: ts.Timestamps,
 			denyReuse:  true,
 		}
+		if keepOriginal {
+			ts = tsOrig
+		}
 		tsAggr.MetricName.CopyFrom(&ts.MetricName)
 		iac = &incrementalAggrContext{
 			ts:     tsAggr,
@@ -138,6 +155,9 @@ type incrementalAggrFuncCallbacks struct {
 	updateAggrFunc   func(iac *incrementalAggrContext, values []float64)
 	mergeAggrFunc    func(dst, src *incrementalAggrContext)
 	finalizeAggrFunc func(iac *incrementalAggrContext)
+
+	// Whether to keep the original MetricName for every time series during aggregation
+	keepOriginal bool
 }
 
 func getIncrementalAggrFuncCallbacks(name string) *incrementalAggrFuncCallbacks {
@@ -485,3 +505,17 @@ func mergeAggrAny(dst, src *incrementalAggrContext) {
 	dstCounts[0] = srcCounts[0]
 	dst.ts.Values = append(dst.ts.Values[:0], srcValues...)
 }
+
+func updateAggrGroup(iac *incrementalAggrContext, values []float64) {
+	dstCounts := iac.values
+	if dstCounts[0] > 0 {
+		return
+	}
+	for i := range values {
+		dstCounts[i] = 1
+	}
+	for i := range values {
+		values[i] = 1
+	}
+	iac.ts.Values = append(iac.ts.Values[:0], values...)
+}
diff --git a/app/vmselect/promql/transform.go b/app/vmselect/promql/transform.go
index e2843d3c1..32f3fe4f3 100644
--- a/app/vmselect/promql/transform.go
+++ b/app/vmselect/promql/transform.go
@@ -1601,11 +1601,16 @@ func transformEnd(tfa *transformFuncArg) float64 {
 	return float64(tfa.ec.End) * 1e-3
 }
 
-// copyTimeseriesMetricNames returns a copy of arg with real copy of MetricNames,
-// but with shallow copy of Timestamps and Values.
-func copyTimeseriesMetricNames(arg []*timeseries) []*timeseries {
-	rvs := make([]*timeseries, len(arg))
-	for i, src := range arg {
+// copyTimeseriesMetricNames returns a copy of tss with real copy of MetricNames,
+// but with shallow copy of Timestamps and Values if makeCopy is set.
+//
+// Otherwise tss is returned.
+func copyTimeseriesMetricNames(tss []*timeseries, makeCopy bool) []*timeseries {
+	if !makeCopy {
+		return tss
+	}
+	rvs := make([]*timeseries, len(tss))
+	for i, src := range tss {
 		var dst timeseries
 		dst.CopyFromMetricNames(src)
 		rvs[i] = &dst