diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 33c2a5760..6a261ca86 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -51,7 +51,7 @@ See also [LTS releases](https://docs.victoriametrics.com/lts-releases/).
 * FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): allow configuring `-remoteWrite.disableOnDiskQueue` and `-remoteWrite.dropSamplesOnOverload` cmd-line flags per each `-remoteWrite.url`. See this [pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6065). Thanks to @rbizos for implementation!
 * FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): add labels `path` and `url` to metrics `vmagent_remotewrite_push_failures_total` and `vmagent_remotewrite_samples_dropped_total`. Now number of failed pushes and dropped samples can be tracked per `-remoteWrite.url`.
 * FEATURE: [stream aggregation](https://docs.victoriametrics.com/stream-aggregation/): add [rate_sum](https://docs.victoriametrics.com/stream-aggregation/#rate_sum) and [rate_avg](https://docs.victoriametrics.com/stream-aggregation/#rate_avg) aggregation outputs.
-* FEATURE: [stream aggregation](https://docs.victoriametrics.com/stream-aggregation/): reduce the number of allocated objects in heap during deduplication and aggregation. The change supposed to reduce pressure on Garbage Collector, as it will need to scan less objects. See [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6402). 
+* FEATURE: [stream aggregation](https://docs.victoriametrics.com/stream-aggregation/): reduce the number of allocated objects in heap during deduplication and aggregation. The change supposed to reduce pressure on Garbage Collector, as it will need to scan less objects. See [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6402).
 * FEATURE: [vmalert](https://docs.victoriametrics.com/vmalert/): add `datasource.idleConnTimeout`, `remoteWrite.idleConnTimeout` and `remoteRead.idleConnTimeout` flags. These flags are set to 50s by default and should reduce the probability of `broken pipe` or `connection reset by peer` errors in vmalert logs. See this [issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5661) for details.
 * FEATURE: [vmalert](https://docs.victoriametrics.com/vmalert/): add auto request retry for trivial network errors, such as `broken pipe` and `connection reset` for requests to `remoteRead`, `remoteWrite` and `datasource` URLs. See this [issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5661) for details.
 * FEATURE: [vmalert](https://docs.victoriametrics.com/vmalert/): reduce CPU usage when evaluating high number of alerting and recording rules.
diff --git a/lib/streamaggr/avg.go b/lib/streamaggr/avg.go
index e3fdfaa4d..2d0546058 100644
--- a/lib/streamaggr/avg.go
+++ b/lib/streamaggr/avg.go
@@ -1,9 +1,9 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
 )
 
@@ -36,7 +36,8 @@ func (as *avgAggrState) pushSamples(samples []pushSample) {
 				sum:   s.value,
 				count: 1,
 			}
-			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
+			outputKey = bytesutil.InternString(outputKey)
+			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The entry has been successfully stored
 				continue
diff --git a/lib/streamaggr/count_samples.go b/lib/streamaggr/count_samples.go
index b23868437..f48ae44dd 100644
--- a/lib/streamaggr/count_samples.go
+++ b/lib/streamaggr/count_samples.go
@@ -1,9 +1,9 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
 )
 
@@ -34,7 +34,8 @@ func (as *countSamplesAggrState) pushSamples(samples []pushSample) {
 			v = &countSamplesStateValue{
 				n: 1,
 			}
-			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
+			outputKey = bytesutil.InternString(outputKey)
+			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The new entry has been successfully created.
 				continue
diff --git a/lib/streamaggr/count_series.go b/lib/streamaggr/count_series.go
index 6348d38f5..edf4a95a4 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 +41,8 @@ func (as *countSeriesAggrState) pushSamples(samples []pushSample) {
 					h: {},
 				},
 			}
-			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
+			outputKey = bytesutil.InternString(outputKey)
+			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The entry has been added to the map.
 				continue
diff --git a/lib/streamaggr/dedup.go b/lib/streamaggr/dedup.go
index 2354499d3..399e9a3dc 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 {
@@ -170,13 +169,14 @@ 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 {
-			m[strings.Clone(sample.key)] = &dedupAggrSample{
+			key := bytesutil.InternString(sample.key)
+			m[key] = dedupAggrSample{
 				value:     sample.value,
 				timestamp: sample.timestamp,
 			}
@@ -184,8 +184,11 @@ func (das *dedupAggrShard) pushSamples(samples []pushSample) {
 		}
 		// Update the existing value according to logic described at https://docs.victoriametrics.com/#deduplication
 		if sample.timestamp > s.timestamp || (sample.timestamp == s.timestamp && sample.value > s.value) {
-			s.value = sample.value
-			s.timestamp = sample.timestamp
+			key := bytesutil.InternString(sample.key)
+			m[key] = dedupAggrSample{
+				value:     sample.value,
+				timestamp: sample.timestamp,
+			}
 		}
 	}
 }
@@ -195,7 +198,7 @@ func (das *dedupAggrShard) flush(ctx *dedupFlushCtx, f func(samples []pushSample
 
 	m := das.m
 	if resetState && len(m) > 0 {
-		das.m = make(map[string]*dedupAggrSample, len(m))
+		das.m = make(map[string]dedupAggrSample, len(m))
 	}
 
 	das.mu.Unlock()
diff --git a/lib/streamaggr/deduplicator.go b/lib/streamaggr/deduplicator.go
index a96d765c2..3ec25f5fa 100644
--- a/lib/streamaggr/deduplicator.go
+++ b/lib/streamaggr/deduplicator.go
@@ -94,8 +94,9 @@ func (d *Deduplicator) Push(tss []prompbmarshal.TimeSeries) {
 		}
 		labels.Sort()
 
-		buf = lc.Compress(buf[:0], labels.Labels)
-		key := bytesutil.InternBytes(buf)
+		bufLen := len(buf)
+		buf = lc.Compress(buf, labels.Labels)
+		key := bytesutil.ToUnsafeString(buf[bufLen:])
 		for _, s := range ts.Samples {
 			pss = append(pss, pushSample{
 				key:       key,
diff --git a/lib/streamaggr/histogram_bucket.go b/lib/streamaggr/histogram_bucket.go
index 519332fd0..4cce32c2d 100644
--- a/lib/streamaggr/histogram_bucket.go
+++ b/lib/streamaggr/histogram_bucket.go
@@ -2,10 +2,10 @@ package streamaggr
 
 import (
 	"math"
-	"strings"
 	"sync"
 	"time"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
 	"github.com/VictoriaMetrics/metrics"
 )
@@ -43,7 +43,8 @@ func (as *histogramBucketAggrState) pushSamples(samples []pushSample) {
 		if !ok {
 			// The entry is missing in the map. Try creating it.
 			v = &histogramBucketStateValue{}
-			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
+			outputKey = bytesutil.InternString(outputKey)
+			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if loaded {
 				// Use the entry created by a concurrent goroutine.
 				v = vNew
diff --git a/lib/streamaggr/last.go b/lib/streamaggr/last.go
index 32410f9d3..9bf4e08e0 100644
--- a/lib/streamaggr/last.go
+++ b/lib/streamaggr/last.go
@@ -1,9 +1,9 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
 )
 
@@ -36,7 +36,8 @@ func (as *lastAggrState) pushSamples(samples []pushSample) {
 				last:      s.value,
 				timestamp: s.timestamp,
 			}
-			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
+			outputKey = bytesutil.InternString(outputKey)
+			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The new entry has been successfully created.
 				continue
diff --git a/lib/streamaggr/max.go b/lib/streamaggr/max.go
index 7a3d6176f..a106d3300 100644
--- a/lib/streamaggr/max.go
+++ b/lib/streamaggr/max.go
@@ -1,9 +1,9 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
 )
 
@@ -34,7 +34,8 @@ func (as *maxAggrState) pushSamples(samples []pushSample) {
 			v = &maxStateValue{
 				max: s.value,
 			}
-			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
+			outputKey = bytesutil.InternString(outputKey)
+			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The new entry has been successfully created.
 				continue
diff --git a/lib/streamaggr/min.go b/lib/streamaggr/min.go
index af81d92ed..b03105c92 100644
--- a/lib/streamaggr/min.go
+++ b/lib/streamaggr/min.go
@@ -1,9 +1,9 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
 )
 
@@ -34,7 +34,8 @@ func (as *minAggrState) pushSamples(samples []pushSample) {
 			v = &minStateValue{
 				min: s.value,
 			}
-			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
+			outputKey = bytesutil.InternString(outputKey)
+			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The new entry has been successfully created.
 				continue
diff --git a/lib/streamaggr/quantiles.go b/lib/streamaggr/quantiles.go
index 0da0f1fae..edaa128f5 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 +41,8 @@ func (as *quantilesAggrState) pushSamples(samples []pushSample) {
 			v = &quantilesStateValue{
 				h: h,
 			}
-			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
+			outputKey = bytesutil.InternString(outputKey)
+			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if loaded {
 				// Use the entry created by a concurrent goroutine.
 				histogram.PutFast(h)
diff --git a/lib/streamaggr/rate.go b/lib/streamaggr/rate.go
index 1eedf1f1d..44e6bcea4 100644
--- a/lib/streamaggr/rate.go
+++ b/lib/streamaggr/rate.go
@@ -4,6 +4,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
 )
 
@@ -59,6 +60,7 @@ func (as *rateAggrState) pushSamples(samples []pushSample) {
 			v = &rateStateValue{
 				lastValues: make(map[string]rateLastValueState),
 			}
+			outputKey = bytesutil.InternString(outputKey)
 			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if loaded {
 				// Use the entry created by a concurrent goroutine.
@@ -89,6 +91,8 @@ func (as *rateAggrState) pushSamples(samples []pushSample) {
 			lv.value = s.value
 			lv.timestamp = s.timestamp
 			lv.deleteDeadline = deleteDeadline
+
+			inputKey = bytesutil.InternString(inputKey)
 			sv.lastValues[inputKey] = lv
 			sv.deleteDeadline = deleteDeadline
 		}
diff --git a/lib/streamaggr/stddev.go b/lib/streamaggr/stddev.go
index 483a9e442..ef10177a0 100644
--- a/lib/streamaggr/stddev.go
+++ b/lib/streamaggr/stddev.go
@@ -2,9 +2,9 @@ package streamaggr
 
 import (
 	"math"
-	"strings"
 	"sync"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
 )
 
@@ -35,7 +35,8 @@ func (as *stddevAggrState) pushSamples(samples []pushSample) {
 		if !ok {
 			// The entry is missing in the map. Try creating it.
 			v = &stddevStateValue{}
-			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
+			outputKey = bytesutil.InternString(outputKey)
+			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if loaded {
 				// Use the entry created by a concurrent goroutine.
 				v = vNew
diff --git a/lib/streamaggr/stdvar.go b/lib/streamaggr/stdvar.go
index a0c4d6df2..dd4c21efe 100644
--- a/lib/streamaggr/stdvar.go
+++ b/lib/streamaggr/stdvar.go
@@ -1,9 +1,9 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
 )
 
@@ -34,7 +34,8 @@ func (as *stdvarAggrState) pushSamples(samples []pushSample) {
 		if !ok {
 			// The entry is missing in the map. Try creating it.
 			v = &stdvarStateValue{}
-			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
+			outputKey = bytesutil.InternString(outputKey)
+			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if loaded {
 				// Use the entry created by a concurrent goroutine.
 				v = vNew
diff --git a/lib/streamaggr/streamaggr.go b/lib/streamaggr/streamaggr.go
index c2465f808..92fdba57a 100644
--- a/lib/streamaggr/streamaggr.go
+++ b/lib/streamaggr/streamaggr.go
@@ -398,7 +398,11 @@ type aggregator struct {
 }
 
 type aggrState interface {
+	// pushSamples must push samples to the aggrState.
+	//
+	// samples[].key must be cloned by aggrState, since it may change after returning from pushSamples.
 	pushSamples(samples []pushSample)
+
 	flushState(ctx *flushCtx, resetState bool)
 }
 
diff --git a/lib/streamaggr/sum_samples.go b/lib/streamaggr/sum_samples.go
index 0e72ebaff..eb621ce5c 100644
--- a/lib/streamaggr/sum_samples.go
+++ b/lib/streamaggr/sum_samples.go
@@ -1,9 +1,9 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
 )
 
@@ -34,7 +34,8 @@ func (as *sumSamplesAggrState) pushSamples(samples []pushSample) {
 			v = &sumSamplesStateValue{
 				sum: s.value,
 			}
-			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
+			outputKey = bytesutil.InternString(outputKey)
+			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The new entry has been successfully created.
 				continue
diff --git a/lib/streamaggr/total.go b/lib/streamaggr/total.go
index ceca2d223..365fdb35d 100644
--- a/lib/streamaggr/total.go
+++ b/lib/streamaggr/total.go
@@ -2,10 +2,10 @@ package streamaggr
 
 import (
 	"math"
-	"strings"
 	"sync"
 	"time"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
 )
 
@@ -81,7 +81,8 @@ func (as *totalAggrState) pushSamples(samples []pushSample) {
 			v = &totalStateValue{
 				lastValues: make(map[string]totalLastValueState),
 			}
-			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
+			outputKey = bytesutil.InternString(outputKey)
+			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if loaded {
 				// Use the entry created by a concurrent goroutine.
 				v = vNew
@@ -109,9 +110,8 @@ func (as *totalAggrState) pushSamples(samples []pushSample) {
 			lv.value = s.value
 			lv.timestamp = s.timestamp
 			lv.deleteDeadline = deleteDeadline
-			if !ok {
-				inputKey = strings.Clone(inputKey)
-			}
+
+			inputKey = bytesutil.InternString(inputKey)
 			sv.lastValues[inputKey] = lv
 			sv.deleteDeadline = deleteDeadline
 		}
diff --git a/lib/streamaggr/unique_samples.go b/lib/streamaggr/unique_samples.go
index 7c11a3883..310617cc7 100644
--- a/lib/streamaggr/unique_samples.go
+++ b/lib/streamaggr/unique_samples.go
@@ -1,9 +1,9 @@
 package streamaggr
 
 import (
-	"strings"
 	"sync"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
 )
 
@@ -36,7 +36,8 @@ func (as *uniqueSamplesAggrState) pushSamples(samples []pushSample) {
 					s.value: {},
 				},
 			}
-			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
+			outputKey = bytesutil.InternString(outputKey)
+			vNew, loaded := as.m.LoadOrStore(outputKey, v)
 			if !loaded {
 				// The new entry has been successfully created.
 				continue