diff --git a/lib/logstorage/block_result.go b/lib/logstorage/block_result.go
index ab556a401..5dfcfc986 100644
--- a/lib/logstorage/block_result.go
+++ b/lib/logstorage/block_result.go
@@ -8,6 +8,7 @@ import (
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/decimal"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/encoding"
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fastnum"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
 )
 
@@ -49,37 +50,29 @@ func (br *blockResult) reset() {
 
 	br.csOffset = 0
 
+	clear(br.cs)
+	br.cs = br.cs[:0]
+}
+
+// setResultColumns sets the given rcs as br columns.
+//
+// The returned result is valid only until rcs are modified.
+func (br *blockResult) setResultColumns(rcs []resultColumn) {
+	br.reset()
+	if len(rcs) == 0 {
+		return
+	}
+	fastnum.AppendInt64Zeros(br.timestamps[:0], len(rcs[0].values))
+
 	cs := br.cs
-	for i := range cs {
-		cs[i].reset()
-	}
-	br.cs = cs[:0]
-}
-
-func (br *blockResult) resetRows() {
-	br.buf = br.buf[:0]
-
-	clear(br.valuesBuf)
-	br.valuesBuf = br.valuesBuf[:0]
-
-	br.timestamps = br.timestamps[:0]
-
-	cs := br.getColumns()
-	for i := range cs {
-		cs[i].resetRows()
-	}
-}
-
-func (br *blockResult) addRow(timestamp int64, values []string) {
-	br.timestamps = append(br.timestamps, timestamp)
-
-	cs := br.getColumns()
-	if len(values) != len(cs) {
-		logger.Panicf("BUG: unexpected number of values in a row; got %d; want %d", len(values), len(cs))
-	}
-	for i := range cs {
-		cs[i].addValue(values[i])
+	for _, rc := range rcs {
+		cs = append(cs, blockResultColumn{
+			name:          rc.name,
+			valueType:     valueTypeString,
+			encodedValues: rc.values,
+		})
 	}
+	br.cs = cs
 }
 
 func (br *blockResult) fetchAllColumns(bs *blockSearch, bm *bitmap) {
@@ -1121,6 +1114,10 @@ func (br *blockResult) truncateRows(keepRows int) {
 	}
 }
 
+// blockResultColumn represents named column from blockResult.
+//
+// blockResultColumn doesn't own any referred data - all the referred data must be owned by blockResult.
+// This simplifies copying, resetting and re-using of the struct.
 type blockResultColumn struct {
 	// name is column name.
 	name string
@@ -1155,49 +1152,6 @@ type blockResultColumn struct {
 
 	// bucketOffset contains bucketOffset for bucketedValues
 	bucketOffset float64
-
-	// buf and valuesBuf are used by addValue() in order to re-use memory across resetRows().
-	buf       []byte
-	valuesBuf []string
-}
-
-func (c *blockResultColumn) reset() {
-	c.name = ""
-	c.isConst = false
-	c.isTime = false
-	c.valueType = valueTypeUnknown
-	c.dictValues = nil
-	c.encodedValues = nil
-	c.values = nil
-
-	c.buf = c.buf[:0]
-
-	clear(c.valuesBuf)
-	c.valuesBuf = c.valuesBuf[:0]
-}
-
-func (c *blockResultColumn) resetRows() {
-	c.dictValues = nil
-	c.encodedValues = nil
-	c.values = nil
-
-	c.buf = c.buf[:0]
-
-	clear(c.valuesBuf)
-	c.valuesBuf = c.valuesBuf[:0]
-}
-
-func (c *blockResultColumn) addValue(v string) {
-	if c.valueType != valueTypeString {
-		logger.Panicf("BUG: unexpected column type; got %d; want %d", c.valueType, valueTypeString)
-	}
-
-	bufLen := len(c.buf)
-	c.buf = append(c.buf, v...)
-	c.valuesBuf = append(c.valuesBuf, bytesutil.ToUnsafeString(c.buf[bufLen:]))
-
-	c.encodedValues = c.valuesBuf
-	c.values = c.valuesBuf
 }
 
 // getValueAtRow returns value for the value at the given rowIdx.
@@ -1593,4 +1547,31 @@ func (c *blockResultColumn) sumValues(br *blockResult) (float64, int) {
 	}
 }
 
+// resultColumn represents a column with result values
+type resultColumn struct {
+	// name is column name.
+	name string
+
+	// buf contains values data.
+	buf []byte
+
+	// values is the result values. They are backed by data inside buf.
+	values []string
+}
+
+func (rc *resultColumn) reset() {
+	rc.name = ""
+	rc.buf = rc.buf[:0]
+
+	clear(rc.values)
+	rc.values = rc.values[:0]
+}
+
+// addValue adds the given values v to rc.
+func (rc *resultColumn) addValue(v string) {
+	bufLen := len(rc.buf)
+	rc.buf = append(rc.buf, v...)
+	rc.values = append(rc.values, bytesutil.ToUnsafeString(rc.buf[bufLen:]))
+}
+
 var nan = math.NaN()
diff --git a/lib/logstorage/pipe_stats.go b/lib/logstorage/pipe_stats.go
index e58d569c7..6334469fd 100644
--- a/lib/logstorage/pipe_stats.go
+++ b/lib/logstorage/pipe_stats.go
@@ -345,15 +345,21 @@ func (psp *pipeStatsProcessor) flush() error {
 		m = shards[0].m
 	}
 
-	var values []string
-	var br blockResult
+	rcs := make([]resultColumn, 0, len(byFields)+len(psp.ps.resultNames))
 	for _, bf := range byFields {
-		br.addEmptyStringColumn(bf.name)
+		rcs = append(rcs, resultColumn{
+			name: bf.name,
+		})
 	}
 	for _, resultName := range psp.ps.resultNames {
-		br.addEmptyStringColumn(resultName)
+		rcs = append(rcs, resultColumn{
+			name: resultName,
+		})
 	}
+	var br blockResult
 
+	var values []string
+	valuesLen := 0
 	for key, spg := 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.
@@ -384,15 +390,25 @@ func (psp *pipeStatsProcessor) flush() error {
 			values = append(values, value)
 		}
 
-		br.addRow(0, values)
-		if len(br.timestamps) >= 1_000 {
+		if len(values) != len(rcs) {
+			logger.Panicf("BUG: len(values)=%d must be equal to len(rcs)=%d", len(values), len(rcs))
+		}
+		for i, v := range values {
+			rcs[i].addValue(v)
+			valuesLen += len(v)
+		}
+		if valuesLen >= 1_000_000 {
+			br.setResultColumns(rcs)
 			psp.ppBase.writeBlock(0, &br)
-			br.resetRows()
+			br.reset()
+			for i := range rcs {
+				rcs[i].reset()
+			}
+			valuesLen = 0
 		}
 	}
-	if len(br.timestamps) > 0 {
-		psp.ppBase.writeBlock(0, &br)
-	}
+	br.setResultColumns(rcs)
+	psp.ppBase.writeBlock(0, &br)
 
 	return nil
 }