diff --git a/lib/logstorage/pipe_stats.go b/lib/logstorage/pipe_stats.go
index bcc34c47a..cf3115ed9 100644
--- a/lib/logstorage/pipe_stats.go
+++ b/lib/logstorage/pipe_stats.go
@@ -166,9 +166,8 @@ func (shard *pipeStatsProcessorShard) writeBlock(br *blockResult) {
 
 	if len(byFields) == 0 {
 		// Fast path - pass all the rows to a single group with empty key.
-		for _, sfp := range shard.getStatsProcessors(nil) {
-			shard.stateSizeBudget -= sfp.updateStatsForAllRows(br)
-		}
+		psg := shard.getPipeStatsGroup(nil)
+		shard.stateSizeBudget -= psg.updateStatsForAllRows(br)
 		return
 	}
 	if len(byFields) == 1 {
@@ -179,9 +178,8 @@ func (shard *pipeStatsProcessorShard) writeBlock(br *blockResult) {
 			// Fast path for column with constant value.
 			v := br.getBucketedValue(c.encodedValues[0], bf.bucketSize, bf.bucketOffset)
 			shard.keyBuf = encoding.MarshalBytes(shard.keyBuf[:0], bytesutil.ToUnsafeBytes(v))
-			for _, sfp := range shard.getStatsProcessors(shard.keyBuf) {
-				shard.stateSizeBudget -= sfp.updateStatsForAllRows(br)
-			}
+			psg := shard.getPipeStatsGroup(shard.keyBuf)
+			shard.stateSizeBudget -= psg.updateStatsForAllRows(br)
 			return
 		}
 
@@ -189,23 +187,20 @@ func (shard *pipeStatsProcessorShard) writeBlock(br *blockResult) {
 		if areConstValues(values) {
 			// Fast path for column with constant values.
 			shard.keyBuf = encoding.MarshalBytes(shard.keyBuf[:0], bytesutil.ToUnsafeBytes(values[0]))
-			for _, sfp := range shard.getStatsProcessors(shard.keyBuf) {
-				shard.stateSizeBudget -= sfp.updateStatsForAllRows(br)
-			}
+			psg := shard.getPipeStatsGroup(shard.keyBuf)
+			shard.stateSizeBudget -= psg.updateStatsForAllRows(br)
 			return
 		}
 
 		// Slower generic path for a column with different values.
-		var sfps []statsProcessor
+		var psg *pipeStatsGroup
 		keyBuf := shard.keyBuf[:0]
 		for i := range br.timestamps {
 			if i <= 0 || values[i-1] != values[i] {
 				keyBuf = encoding.MarshalBytes(keyBuf[:0], bytesutil.ToUnsafeBytes(values[i]))
-				sfps = shard.getStatsProcessors(keyBuf)
-			}
-			for _, sfp := range sfps {
-				shard.stateSizeBudget -= sfp.updateStatsForRow(br, i)
+				psg = shard.getPipeStatsGroup(keyBuf)
 			}
+			shard.stateSizeBudget -= psg.updateStatsForRow(br, i)
 		}
 		shard.keyBuf = keyBuf
 		return
@@ -234,19 +229,18 @@ func (shard *pipeStatsProcessorShard) writeBlock(br *blockResult) {
 		for _, values := range columnValues {
 			keyBuf = encoding.MarshalBytes(keyBuf, bytesutil.ToUnsafeBytes(values[0]))
 		}
-		for _, sfp := range shard.getStatsProcessors(keyBuf) {
-			shard.stateSizeBudget -= sfp.updateStatsForAllRows(br)
-		}
+		psg := shard.getPipeStatsGroup(keyBuf)
+		shard.stateSizeBudget -= psg.updateStatsForAllRows(br)
 		shard.keyBuf = keyBuf
 		return
 	}
 
 	// The slowest path - group by multiple columns with different values across rows.
-	var sfps []statsProcessor
+	var psg *pipeStatsGroup
 	keyBuf := shard.keyBuf[:0]
 	for i := range br.timestamps {
 		// Verify whether the key for 'by (...)' fields equals the previous key
-		sameValue := sfps != nil
+		sameValue := i > 0
 		for _, values := range columnValues {
 			if i <= 0 || values[i-1] != values[i] {
 				sameValue = false
@@ -259,37 +253,54 @@ func (shard *pipeStatsProcessorShard) writeBlock(br *blockResult) {
 			for _, values := range columnValues {
 				keyBuf = encoding.MarshalBytes(keyBuf, bytesutil.ToUnsafeBytes(values[i]))
 			}
-			sfps = shard.getStatsProcessors(keyBuf)
-		}
-		for _, sfp := range sfps {
-			shard.stateSizeBudget -= sfp.updateStatsForRow(br, i)
+			psg = shard.getPipeStatsGroup(keyBuf)
 		}
+		shard.stateSizeBudget -= psg.updateStatsForRow(br, i)
 	}
 	shard.keyBuf = keyBuf
 }
 
-func (shard *pipeStatsProcessorShard) getStatsProcessors(key []byte) []statsProcessor {
-	spg := shard.m[string(key)]
-	if spg == nil {
-		sfps := make([]statsProcessor, len(shard.ps.funcs))
-		for i, f := range shard.ps.funcs {
-			sfp, stateSize := f.newStatsProcessor()
-			sfps[i] = sfp
-			shard.stateSizeBudget -= stateSize
-		}
-		spg = &pipeStatsGroup{
-			sfps: sfps,
-		}
-		shard.m[string(key)] = spg
-		shard.stateSizeBudget -= len(key) + int(unsafe.Sizeof("")+unsafe.Sizeof(spg)+unsafe.Sizeof(sfps[0])*uintptr(len(sfps)))
+func (shard *pipeStatsProcessorShard) getPipeStatsGroup(key []byte) *pipeStatsGroup {
+	psg := shard.m[string(key)]
+	if psg != nil {
+		return psg
 	}
-	return spg.sfps
+
+	sfps := make([]statsProcessor, len(shard.ps.funcs))
+	for i, f := range shard.ps.funcs {
+		sfp, stateSize := f.newStatsProcessor()
+		sfps[i] = sfp
+		shard.stateSizeBudget -= stateSize
+	}
+	psg = &pipeStatsGroup{
+		sfps: sfps,
+	}
+	shard.m[string(key)] = psg
+	shard.stateSizeBudget -= len(key) + int(unsafe.Sizeof("")+unsafe.Sizeof(psg)+unsafe.Sizeof(sfps[0])*uintptr(len(sfps)))
+
+	return psg
 }
 
 type pipeStatsGroup struct {
 	sfps []statsProcessor
 }
 
+func (psg *pipeStatsGroup) updateStatsForAllRows(br *blockResult) int {
+	n := 0
+	for _, sfp := range psg.sfps {
+		n += sfp.updateStatsForAllRows(br)
+	}
+	return n
+}
+
+func (psg *pipeStatsGroup) updateStatsForRow(br *blockResult, rowIdx int) int {
+	n := 0
+	for _, sfp := range psg.sfps {
+		n += sfp.updateStatsForRow(br, rowIdx)
+	}
+	return n
+}
+
 func (psp *pipeStatsProcessor) writeBlock(workerID uint, br *blockResult) {
 	if len(br.timestamps) == 0 {
 		return
@@ -325,7 +336,7 @@ func (psp *pipeStatsProcessor) flush() error {
 	shards = shards[1:]
 	for i := range shards {
 		shard := &shards[i]
-		for key, spg := range shard.m {
+		for key, psg := range shard.m {
 			// shard.m may be quite big, so this loop can take a lot of time and CPU.
 			// Stop processing data as soon as stopCh is closed without wasting additional CPU time.
 			select {
@@ -336,10 +347,10 @@ func (psp *pipeStatsProcessor) flush() error {
 
 			spgBase := m[key]
 			if spgBase == nil {
-				m[key] = spg
+				m[key] = psg
 			} else {
 				for i, sfp := range spgBase.sfps {
-					sfp.mergeState(spg.sfps[i])
+					sfp.mergeState(psg.sfps[i])
 				}
 			}
 		}
@@ -349,7 +360,7 @@ func (psp *pipeStatsProcessor) flush() error {
 	byFields := psp.ps.byFields
 	if len(byFields) == 0 && len(m) == 0 {
 		// Special case - zero matching rows.
-		_ = shards[0].getStatsProcessors(nil)
+		_ = shards[0].getPipeStatsGroup(nil)
 		m = shards[0].m
 	}
 
@@ -368,7 +379,7 @@ func (psp *pipeStatsProcessor) flush() error {
 
 	var values []string
 	valuesLen := 0
-	for key, spg := range m {
+	for key, psg := range m {
 		// m may be quite big, so this loop can take a lot of time and CPU.
 		// Stop processing data as soon as stopCh is closed without wasting additional CPU time.
 		select {
@@ -393,7 +404,7 @@ func (psp *pipeStatsProcessor) flush() error {
 		}
 
 		// calculate values for stats functions
-		for _, sfp := range spg.sfps {
+		for _, sfp := range psg.sfps {
 			value := sfp.finalizeStats()
 			values = append(values, value)
 		}
diff --git a/lib/logstorage/stats_count_uniq.go b/lib/logstorage/stats_count_uniq.go
index 014139595..6b0885961 100644
--- a/lib/logstorage/stats_count_uniq.go
+++ b/lib/logstorage/stats_count_uniq.go
@@ -13,7 +13,7 @@ import (
 type statsCountUniq struct {
 	fields       []string
 	containsStar bool
-	limit uint64
+	limit        uint64
 }
 
 func (su *statsCountUniq) String() string {
diff --git a/lib/logstorage/stats_uniq_values.go b/lib/logstorage/stats_uniq_values.go
index f240a77e5..e13991945 100644
--- a/lib/logstorage/stats_uniq_values.go
+++ b/lib/logstorage/stats_uniq_values.go
@@ -13,7 +13,7 @@ import (
 type statsUniqValues struct {
 	fields       []string
 	containsStar bool
-	limit uint64
+	limit        uint64
 }
 
 func (su *statsUniqValues) String() string {