diff --git a/lib/streamaggr/avg.go b/lib/streamaggr/avg.go
index c629af8d9..079e3b5c8 100644
--- a/lib/streamaggr/avg.go
+++ b/lib/streamaggr/avg.go
@@ -1,7 +1,6 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -36,7 +35,6 @@ func (as *avgAggrState) pushSamples(samples []pushSample) {
 				sum:   s.value,
 				count: 1,
 			}
-			outputKey = strings.Clone(outputKey)
 			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The entry has been successfully stored
diff --git a/lib/streamaggr/count_samples.go b/lib/streamaggr/count_samples.go
index 807fbdfba..ac0431deb 100644
--- a/lib/streamaggr/count_samples.go
+++ b/lib/streamaggr/count_samples.go
@@ -1,7 +1,6 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -34,7 +33,6 @@ func (as *countSamplesAggrState) pushSamples(samples []pushSample) {
 			v = &countSamplesStateValue{
 				n: 1,
 			}
-			outputKey = strings.Clone(outputKey)
 			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The new entry has been successfully created.
diff --git a/lib/streamaggr/count_series.go b/lib/streamaggr/count_series.go
index e78ce9273..5bfbd4c34 100644
--- a/lib/streamaggr/count_series.go
+++ b/lib/streamaggr/count_series.go
@@ -1,7 +1,6 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
@@ -42,7 +41,6 @@ func (as *countSeriesAggrState) pushSamples(samples []pushSample) {
 					h: {},
 				},
 			}
-			outputKey = strings.Clone(outputKey)
 			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The entry has been added to the map.
diff --git a/lib/streamaggr/dedup.go b/lib/streamaggr/dedup.go
index e4570f065..35e520ced 100644
--- a/lib/streamaggr/dedup.go
+++ b/lib/streamaggr/dedup.go
@@ -1,7 +1,6 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 	"unsafe"
 
@@ -25,7 +24,7 @@ type dedupAggrShard struct {
 
 type dedupAggrShardNopad struct {
 	mu sync.Mutex
-	m  map[string]*dedupAggrSample
+	m  map[string]dedupAggrSample
 }
 
 type dedupAggrSample struct {
@@ -59,7 +58,7 @@ func (das *dedupAggrShard) sizeBytes() uint64 {
 	das.mu.Lock()
 	n := uint64(unsafe.Sizeof(*das))
 	for k, s := range das.m {
-		n += uint64(len(k)) + uint64(unsafe.Sizeof(k)+unsafe.Sizeof(s)+unsafe.Sizeof(*s))
+		n += uint64(len(k)) + uint64(unsafe.Sizeof(k)+unsafe.Sizeof(s))
 	}
 	das.mu.Unlock()
 	return n
@@ -169,18 +168,12 @@ func (das *dedupAggrShard) pushSamples(samples []pushSample) {
 
 	m := das.m
 	if m == nil {
-		m = make(map[string]*dedupAggrSample, len(samples))
+		m = make(map[string]dedupAggrSample, len(samples))
 		das.m = m
 	}
 	for _, sample := range samples {
-		s, ok := m[sample.key]
-		if ok {
-			s.value = sample.value
-		} else {
-			key := strings.Clone(sample.key)
-			m[key] = &dedupAggrSample{
-				value: sample.value,
-			}
+		m[sample.key] = dedupAggrSample{
+			value: sample.value,
 		}
 	}
 }
@@ -189,7 +182,9 @@ func (das *dedupAggrShard) flush(ctx *dedupFlushCtx, f func(samples []pushSample
 	das.mu.Lock()
 
 	m := das.m
-	das.m = nil
+	if len(m) != 0 {
+		das.m = make(map[string]dedupAggrSample, len(m))
+	}
 
 	das.mu.Unlock()
 
diff --git a/lib/streamaggr/dedup_test.go b/lib/streamaggr/dedup_test.go
index c3892a5f8..663bf6563 100644
--- a/lib/streamaggr/dedup_test.go
+++ b/lib/streamaggr/dedup_test.go
@@ -3,7 +3,6 @@ package streamaggr
 import (
 	"fmt"
 	"reflect"
-	"strings"
 	"sync"
 	"sync/atomic"
 	"testing"
@@ -25,8 +24,8 @@ func TestDedupAggrSerial(t *testing.T) {
 		da.pushSamples(samples)
 	}
 
-	if n := da.sizeBytes(); n > 4_200_000 {
-		t.Fatalf("too big dedupAggr state before flush: %d bytes; it shouldn't exceed 4_200_000 bytes", n)
+	if n := da.sizeBytes(); n > 3_400_000 {
+		t.Fatalf("too big dedupAggr state before flush: %d bytes; it shouldn't exceed 3_400_000 bytes", n)
 	}
 	if n := da.itemsCount(); n != seriesCount {
 		t.Fatalf("unexpected itemsCount; got %d; want %d", n, seriesCount)
@@ -37,7 +36,6 @@ func TestDedupAggrSerial(t *testing.T) {
 	flushSamples := func(samples []pushSample) {
 		mu.Lock()
 		for _, sample := range samples {
-			sample.key = strings.Clone(sample.key)
 			flushedSamplesMap[sample.key] = sample
 		}
 		mu.Unlock()
diff --git a/lib/streamaggr/histogram_bucket.go b/lib/streamaggr/histogram_bucket.go
index 1430b2e58..0d073abf3 100644
--- a/lib/streamaggr/histogram_bucket.go
+++ b/lib/streamaggr/histogram_bucket.go
@@ -2,7 +2,6 @@ package streamaggr
 
 import (
 	"math"
-	"strings"
 	"sync"
 	"time"
 
@@ -43,7 +42,6 @@ func (as *histogramBucketAggrState) pushSamples(samples []pushSample) {
 		if !ok {
 			// The entry is missing in the map. Try creating it.
 			v = &histogramBucketStateValue{}
-			outputKey = strings.Clone(outputKey)
 			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if loaded {
 				// Use the entry created by a concurrent goroutine.
diff --git a/lib/streamaggr/last.go b/lib/streamaggr/last.go
index 667251076..6ba46b349 100644
--- a/lib/streamaggr/last.go
+++ b/lib/streamaggr/last.go
@@ -1,7 +1,6 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -34,7 +33,6 @@ func (as *lastAggrState) pushSamples(samples []pushSample) {
 			v = &lastStateValue{
 				last: s.value,
 			}
-			outputKey = strings.Clone(outputKey)
 			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The new entry has been successfully created.
diff --git a/lib/streamaggr/max.go b/lib/streamaggr/max.go
index 4450e210a..76320a090 100644
--- a/lib/streamaggr/max.go
+++ b/lib/streamaggr/max.go
@@ -1,7 +1,6 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -34,7 +33,6 @@ func (as *maxAggrState) pushSamples(samples []pushSample) {
 			v = &maxStateValue{
 				max: s.value,
 			}
-			outputKey = strings.Clone(outputKey)
 			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The new entry has been successfully created.
diff --git a/lib/streamaggr/min.go b/lib/streamaggr/min.go
index 42d8a2314..cde503312 100644
--- a/lib/streamaggr/min.go
+++ b/lib/streamaggr/min.go
@@ -1,7 +1,6 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -34,7 +33,6 @@ func (as *minAggrState) pushSamples(samples []pushSample) {
 			v = &minStateValue{
 				min: s.value,
 			}
-			outputKey = strings.Clone(outputKey)
 			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The new entry has been successfully created.
diff --git a/lib/streamaggr/quantiles.go b/lib/streamaggr/quantiles.go
index 4e605cc91..f9ec321d1 100644
--- a/lib/streamaggr/quantiles.go
+++ b/lib/streamaggr/quantiles.go
@@ -2,7 +2,6 @@ package streamaggr
 
 import (
 	"strconv"
-	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
@@ -42,7 +41,6 @@ func (as *quantilesAggrState) pushSamples(samples []pushSample) {
 			v = &quantilesStateValue{
 				h: h,
 			}
-			outputKey = strings.Clone(outputKey)
 			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if loaded {
 				// Use the entry created by a concurrent goroutine.
diff --git a/lib/streamaggr/stddev.go b/lib/streamaggr/stddev.go
index 777573ea3..2a5b3e3d4 100644
--- a/lib/streamaggr/stddev.go
+++ b/lib/streamaggr/stddev.go
@@ -2,7 +2,6 @@ package streamaggr
 
 import (
 	"math"
-	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -35,7 +34,6 @@ func (as *stddevAggrState) pushSamples(samples []pushSample) {
 		if !ok {
 			// The entry is missing in the map. Try creating it.
 			v = &stddevStateValue{}
-			outputKey = strings.Clone(outputKey)
 			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if loaded {
 				// Use the entry created by a concurrent goroutine.
diff --git a/lib/streamaggr/stdvar.go b/lib/streamaggr/stdvar.go
index c6f5cfed9..450b2feef 100644
--- a/lib/streamaggr/stdvar.go
+++ b/lib/streamaggr/stdvar.go
@@ -1,7 +1,6 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -34,7 +33,6 @@ func (as *stdvarAggrState) pushSamples(samples []pushSample) {
 		if !ok {
 			// The entry is missing in the map. Try creating it.
 			v = &stdvarStateValue{}
-			outputKey = strings.Clone(outputKey)
 			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if loaded {
 				// Use the entry created by a concurrent goroutine.
diff --git a/lib/streamaggr/streamaggr.go b/lib/streamaggr/streamaggr.go
index c941073fb..8d98a7071 100644
--- a/lib/streamaggr/streamaggr.go
+++ b/lib/streamaggr/streamaggr.go
@@ -757,15 +757,15 @@ func (a *aggregator) Push(tss []prompbmarshal.TimeSeries, matchIdxs []byte) {
 			outputLabels.Labels = append(outputLabels.Labels, labels.Labels...)
 		}
 
-		bufLen := len(buf)
-		buf = a.compressLabels(buf, inputLabels.Labels, outputLabels.Labels)
+		buf = a.compressLabels(buf[:0], inputLabels.Labels, outputLabels.Labels)
+		key := bytesutil.InternBytes(buf)
 		for _, sample := range ts.Samples {
 			if math.IsNaN(sample.Value) {
 				// Skip NaN values
 				continue
 			}
 			samples = append(samples, pushSample{
-				key:   bytesutil.ToUnsafeString(buf[bufLen:]),
+				key:   key,
 				value: sample.Value,
 			})
 		}
diff --git a/lib/streamaggr/sum_samples.go b/lib/streamaggr/sum_samples.go
index 080df9347..4d88dc4f6 100644
--- a/lib/streamaggr/sum_samples.go
+++ b/lib/streamaggr/sum_samples.go
@@ -1,7 +1,6 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -34,7 +33,6 @@ func (as *sumSamplesAggrState) pushSamples(samples []pushSample) {
 			v = &sumSamplesStateValue{
 				sum: s.value,
 			}
-			outputKey = strings.Clone(outputKey)
 			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The new entry has been successfully created.
diff --git a/lib/streamaggr/total.go b/lib/streamaggr/total.go
index 516694ea6..78f8bd36f 100644
--- a/lib/streamaggr/total.go
+++ b/lib/streamaggr/total.go
@@ -2,7 +2,6 @@ package streamaggr
 
 import (
 	"math"
-	"strings"
 	"sync"
 	"time"
 
@@ -77,7 +76,6 @@ func (as *totalAggrState) pushSamples(samples []pushSample) {
 			v = &totalStateValue{
 				lastValues: make(map[string]*lastValueState),
 			}
-			outputKey = strings.Clone(outputKey)
 			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if loaded {
 				// Use the entry created by a concurrent goroutine.
@@ -91,7 +89,6 @@ func (as *totalAggrState) pushSamples(samples []pushSample) {
 			lv, ok := sv.lastValues[inputKey]
 			if !ok {
 				lv = &lastValueState{}
-				inputKey = strings.Clone(inputKey)
 				sv.lastValues[inputKey] = lv
 			}
 			if ok || keepFirstSample {
diff --git a/lib/streamaggr/unique_samples.go b/lib/streamaggr/unique_samples.go
index 60cd3317d..2c5e97828 100644
--- a/lib/streamaggr/unique_samples.go
+++ b/lib/streamaggr/unique_samples.go
@@ -1,7 +1,6 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -36,7 +35,6 @@ func (as *uniqueSamplesAggrState) pushSamples(samples []pushSample) {
 					s.value: {},
 				},
 			}
-			outputKey = strings.Clone(outputKey)
 			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The new entry has been successfully created.