diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index e41464b3a7..33c2a57607 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -51,6 +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: [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 131c9a8a0c..e3fdfaa4d7 100644
--- a/lib/streamaggr/avg.go
+++ b/lib/streamaggr/avg.go
@@ -1,6 +1,7 @@
 package streamaggr
 
 import (
+	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -35,7 +36,7 @@ func (as *avgAggrState) pushSamples(samples []pushSample) {
 				sum:   s.value,
 				count: 1,
 			}
-			vNew, loaded := as.m.LoadOrStore(outputKey, v)
+			vNew, loaded := as.m.LoadOrStore(strings.Clone(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 30099d4bd7..b238684371 100644
--- a/lib/streamaggr/count_samples.go
+++ b/lib/streamaggr/count_samples.go
@@ -1,6 +1,7 @@
 package streamaggr
 
 import (
+	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -33,7 +34,7 @@ func (as *countSamplesAggrState) pushSamples(samples []pushSample) {
 			v = &countSamplesStateValue{
 				n: 1,
 			}
-			vNew, loaded := as.m.LoadOrStore(outputKey, v)
+			vNew, loaded := as.m.LoadOrStore(strings.Clone(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 a80c69dbba..6348d38f50 100644
--- a/lib/streamaggr/count_series.go
+++ b/lib/streamaggr/count_series.go
@@ -1,6 +1,7 @@
 package streamaggr
 
 import (
+	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
@@ -41,7 +42,7 @@ func (as *countSeriesAggrState) pushSamples(samples []pushSample) {
 					h: {},
 				},
 			}
-			vNew, loaded := as.m.LoadOrStore(outputKey, v)
+			vNew, loaded := as.m.LoadOrStore(strings.Clone(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 c9ac3dc676..2354499d3b 100644
--- a/lib/streamaggr/dedup.go
+++ b/lib/streamaggr/dedup.go
@@ -1,6 +1,7 @@
 package streamaggr
 
 import (
+	"strings"
 	"sync"
 	"unsafe"
 
@@ -24,7 +25,7 @@ type dedupAggrShard struct {
 
 type dedupAggrShardNopad struct {
 	mu sync.Mutex
-	m  map[string]dedupAggrSample
+	m  map[string]*dedupAggrSample
 }
 
 type dedupAggrSample struct {
@@ -169,13 +170,13 @@ 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[sample.key] = dedupAggrSample{
+			m[strings.Clone(sample.key)] = &dedupAggrSample{
 				value:     sample.value,
 				timestamp: sample.timestamp,
 			}
@@ -183,10 +184,8 @@ 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) {
-			m[sample.key] = dedupAggrSample{
-				value:     sample.value,
-				timestamp: sample.timestamp,
-			}
+			s.value = sample.value
+			s.timestamp = sample.timestamp
 		}
 	}
 }
@@ -196,7 +195,7 @@ 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/histogram_bucket.go b/lib/streamaggr/histogram_bucket.go
index aba933ae47..519332fd0f 100644
--- a/lib/streamaggr/histogram_bucket.go
+++ b/lib/streamaggr/histogram_bucket.go
@@ -2,6 +2,7 @@ package streamaggr
 
 import (
 	"math"
+	"strings"
 	"sync"
 	"time"
 
@@ -42,7 +43,7 @@ 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(outputKey, v)
+			vNew, loaded := as.m.LoadOrStore(strings.Clone(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 c8c7881edf..32410f9d3b 100644
--- a/lib/streamaggr/last.go
+++ b/lib/streamaggr/last.go
@@ -1,6 +1,7 @@
 package streamaggr
 
 import (
+	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -35,7 +36,7 @@ func (as *lastAggrState) pushSamples(samples []pushSample) {
 				last:      s.value,
 				timestamp: s.timestamp,
 			}
-			vNew, loaded := as.m.LoadOrStore(outputKey, v)
+			vNew, loaded := as.m.LoadOrStore(strings.Clone(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 f92036c66a..7a3d6176f6 100644
--- a/lib/streamaggr/max.go
+++ b/lib/streamaggr/max.go
@@ -1,6 +1,7 @@
 package streamaggr
 
 import (
+	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -33,7 +34,7 @@ func (as *maxAggrState) pushSamples(samples []pushSample) {
 			v = &maxStateValue{
 				max: s.value,
 			}
-			vNew, loaded := as.m.LoadOrStore(outputKey, v)
+			vNew, loaded := as.m.LoadOrStore(strings.Clone(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 17137e6cdb..af81d92ede 100644
--- a/lib/streamaggr/min.go
+++ b/lib/streamaggr/min.go
@@ -1,6 +1,7 @@
 package streamaggr
 
 import (
+	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -33,7 +34,7 @@ func (as *minAggrState) pushSamples(samples []pushSample) {
 			v = &minStateValue{
 				min: s.value,
 			}
-			vNew, loaded := as.m.LoadOrStore(outputKey, v)
+			vNew, loaded := as.m.LoadOrStore(strings.Clone(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 b97697ebbb..0da0f1faee 100644
--- a/lib/streamaggr/quantiles.go
+++ b/lib/streamaggr/quantiles.go
@@ -2,6 +2,7 @@ package streamaggr
 
 import (
 	"strconv"
+	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
@@ -41,7 +42,7 @@ func (as *quantilesAggrState) pushSamples(samples []pushSample) {
 			v = &quantilesStateValue{
 				h: h,
 			}
-			vNew, loaded := as.m.LoadOrStore(outputKey, v)
+			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
 			if loaded {
 				// Use the entry created by a concurrent goroutine.
 				histogram.PutFast(h)
diff --git a/lib/streamaggr/stddev.go b/lib/streamaggr/stddev.go
index 0eb6df6fec..483a9e4420 100644
--- a/lib/streamaggr/stddev.go
+++ b/lib/streamaggr/stddev.go
@@ -2,6 +2,7 @@ package streamaggr
 
 import (
 	"math"
+	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -34,7 +35,7 @@ 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(outputKey, v)
+			vNew, loaded := as.m.LoadOrStore(strings.Clone(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 c5d46af2ae..a0c4d6df28 100644
--- a/lib/streamaggr/stdvar.go
+++ b/lib/streamaggr/stdvar.go
@@ -1,6 +1,7 @@
 package streamaggr
 
 import (
+	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -33,7 +34,7 @@ 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(outputKey, v)
+			vNew, loaded := as.m.LoadOrStore(strings.Clone(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 625a0b570d..c2465f8082 100644
--- a/lib/streamaggr/streamaggr.go
+++ b/lib/streamaggr/streamaggr.go
@@ -845,8 +845,11 @@ func (a *aggregator) Push(tss []prompbmarshal.TimeSeries, matchIdxs []byte) {
 			outputLabels.Labels = append(outputLabels.Labels, labels.Labels...)
 		}
 
-		buf = compressLabels(buf[:0], inputLabels.Labels, outputLabels.Labels)
-		key := bytesutil.InternBytes(buf)
+		bufLen := len(buf)
+		buf = compressLabels(buf, inputLabels.Labels, outputLabels.Labels)
+		// key remains valid only by the end of this function and can't be reused after
+		// do not intern key because number of unique keys could be too high
+		key := bytesutil.ToUnsafeString(buf[bufLen:])
 		for _, sample := range ts.Samples {
 			if math.IsNaN(sample.Value) {
 				a.ignoredNanSamples.Inc()
@@ -942,6 +945,8 @@ func (ctx *pushCtx) reset() {
 }
 
 type pushSample struct {
+	// key identifies a sample that belongs to unique series
+	// key value can't be re-used
 	key       string
 	value     float64
 	timestamp int64
diff --git a/lib/streamaggr/sum_samples.go b/lib/streamaggr/sum_samples.go
index bbd63fd0ef..0e72ebaffd 100644
--- a/lib/streamaggr/sum_samples.go
+++ b/lib/streamaggr/sum_samples.go
@@ -1,6 +1,7 @@
 package streamaggr
 
 import (
+	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -33,7 +34,7 @@ func (as *sumSamplesAggrState) pushSamples(samples []pushSample) {
 			v = &sumSamplesStateValue{
 				sum: s.value,
 			}
-			vNew, loaded := as.m.LoadOrStore(outputKey, v)
+			vNew, loaded := as.m.LoadOrStore(strings.Clone(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 b53d326d32..ceca2d2234 100644
--- a/lib/streamaggr/total.go
+++ b/lib/streamaggr/total.go
@@ -2,6 +2,7 @@ package streamaggr
 
 import (
 	"math"
+	"strings"
 	"sync"
 	"time"
 
@@ -80,7 +81,7 @@ func (as *totalAggrState) pushSamples(samples []pushSample) {
 			v = &totalStateValue{
 				lastValues: make(map[string]totalLastValueState),
 			}
-			vNew, loaded := as.m.LoadOrStore(outputKey, v)
+			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
 			if loaded {
 				// Use the entry created by a concurrent goroutine.
 				v = vNew
@@ -108,6 +109,9 @@ func (as *totalAggrState) pushSamples(samples []pushSample) {
 			lv.value = s.value
 			lv.timestamp = s.timestamp
 			lv.deleteDeadline = deleteDeadline
+			if !ok {
+				inputKey = strings.Clone(inputKey)
+			}
 			sv.lastValues[inputKey] = lv
 			sv.deleteDeadline = deleteDeadline
 		}
diff --git a/lib/streamaggr/unique_samples.go b/lib/streamaggr/unique_samples.go
index 4f10b5c02b..7c11a38838 100644
--- a/lib/streamaggr/unique_samples.go
+++ b/lib/streamaggr/unique_samples.go
@@ -1,6 +1,7 @@
 package streamaggr
 
 import (
+	"strings"
 	"sync"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fasttime"
@@ -35,7 +36,7 @@ func (as *uniqueSamplesAggrState) pushSamples(samples []pushSample) {
 					s.value: {},
 				},
 			}
-			vNew, loaded := as.m.LoadOrStore(outputKey, v)
+			vNew, loaded := as.m.LoadOrStore(strings.Clone(outputKey), v)
 			if !loaded {
 				// The new entry has been successfully created.
 				continue