diff --git a/lib/logstorage/fields_set.go b/lib/logstorage/fields_set.go
index 00f803fee..faf52ce9d 100644
--- a/lib/logstorage/fields_set.go
+++ b/lib/logstorage/fields_set.go
@@ -37,13 +37,13 @@ func (fs fieldsSet) getAll() []string {
 	return a
 }
 
-func (fs fieldsSet) addAll(fields []string) {
+func (fs fieldsSet) addFields(fields []string) {
 	for _, f := range fields {
 		fs.add(f)
 	}
 }
 
-func (fs fieldsSet) removeAll(fields []string) {
+func (fs fieldsSet) removeFields(fields []string) {
 	for _, f := range fields {
 		fs.remove(f)
 	}
diff --git a/lib/logstorage/fields_set_test.go b/lib/logstorage/fields_set_test.go
index 6e848ac13..c0a86d50b 100644
--- a/lib/logstorage/fields_set_test.go
+++ b/lib/logstorage/fields_set_test.go
@@ -73,8 +73,8 @@ func TestFieldsSet(t *testing.T) {
 		t.Fatalf("fs must be empty")
 	}
 
-	// verify addAll, getAll, removeAll
-	fs.addAll([]string{"foo", "bar", "_msg"})
+	// verify addFields, removeFields, getAll
+	fs.addFields([]string{"foo", "bar", "_msg"})
 	if !fs.contains("foo") || !fs.contains("bar") || !fs.contains("_msg") {
 		t.Fatalf("fs must contain foo, bar and _msg")
 	}
@@ -82,7 +82,7 @@ func TestFieldsSet(t *testing.T) {
 	if !reflect.DeepEqual(a, []string{"_msg", "bar", "foo"}) {
 		t.Fatalf("unexpected result from getAll(); got %q; want %q", a, []string{"_msg", "bar", "foo"})
 	}
-	fs.removeAll([]string{"bar", "baz", "_msg"})
+	fs.removeFields([]string{"bar", "baz", "_msg"})
 	if fs.contains("bar") || fs.contains("baz") || fs.contains("_msg") {
 		t.Fatalf("fs mustn't contain bar, baz and _msg")
 	}
@@ -91,7 +91,7 @@ func TestFieldsSet(t *testing.T) {
 	}
 
 	// verify clone
-	fs.addAll([]string{"foo", "bar", "baz"})
+	fs.addFields([]string{"foo", "bar", "baz"})
 	fsStr := fs.String()
 	fsCopy := fs.clone()
 	fsCopyStr := fsCopy.String()
diff --git a/lib/logstorage/pipe_copy.go b/lib/logstorage/pipe_copy.go
index cd4cccfe7..d512bb0d5 100644
--- a/lib/logstorage/pipe_copy.go
+++ b/lib/logstorage/pipe_copy.go
@@ -40,7 +40,7 @@ func (pc *pipeCopy) updateNeededFields(neededFields, unneededFields fieldsSet) {
 	}
 	if neededFields.contains("*") {
 		// update only unneeded fields
-		unneededFields.addAll(pc.dstFields)
+		unneededFields.addFields(pc.dstFields)
 		for i, srcField := range pc.srcFields {
 			if neededSrcFields[i] {
 				unneededFields.remove(srcField)
@@ -48,7 +48,7 @@ func (pc *pipeCopy) updateNeededFields(neededFields, unneededFields fieldsSet) {
 		}
 	} else {
 		// update only needed fields and reset unneeded fields
-		neededFields.removeAll(pc.dstFields)
+		neededFields.removeFields(pc.dstFields)
 		for i, srcField := range pc.srcFields {
 			if neededSrcFields[i] {
 				neededFields.add(srcField)
diff --git a/lib/logstorage/pipe_copy_test.go b/lib/logstorage/pipe_copy_test.go
index 32b7e2d63..c5dc5ed0f 100644
--- a/lib/logstorage/pipe_copy_test.go
+++ b/lib/logstorage/pipe_copy_test.go
@@ -75,7 +75,7 @@ func assertNeededFields(t *testing.T, nfs, unfs fieldsSet, neededFieldsExpected,
 func newTestFieldsSet(fields string) fieldsSet {
 	fs := newFieldsSet()
 	if fields != "" {
-		fs.addAll(strings.Split(fields, ","))
+		fs.addFields(strings.Split(fields, ","))
 	}
 	return fs
 }
diff --git a/lib/logstorage/pipe_delete.go b/lib/logstorage/pipe_delete.go
index efcca0da3..3389cc94e 100644
--- a/lib/logstorage/pipe_delete.go
+++ b/lib/logstorage/pipe_delete.go
@@ -25,10 +25,10 @@ func (pd *pipeDelete) String() string {
 func (pd *pipeDelete) updateNeededFields(neededFields, unneededFields fieldsSet) {
 	if neededFields.contains("*") {
 		// update only unneeded fields
-		unneededFields.addAll(pd.fields)
+		unneededFields.addFields(pd.fields)
 	} else {
 		// update only needed fields
-		neededFields.removeAll(pd.fields)
+		neededFields.removeFields(pd.fields)
 	}
 }
 
diff --git a/lib/logstorage/pipe_fields.go b/lib/logstorage/pipe_fields.go
index 20a5a15de..07298c6dd 100644
--- a/lib/logstorage/pipe_fields.go
+++ b/lib/logstorage/pipe_fields.go
@@ -32,7 +32,7 @@ func (pf *pipeFields) updateNeededFields(neededFields, unneededFields fieldsSet)
 	if neededFields.contains("*") {
 		// subtract unneeded fields from pf.fields
 		neededFields.reset()
-		neededFields.addAll(pf.fields)
+		neededFields.addFields(pf.fields)
 		for _, f := range unneededFields.getAll() {
 			neededFields.remove(f)
 		}
diff --git a/lib/logstorage/pipe_rename.go b/lib/logstorage/pipe_rename.go
index 0eb48af39..99a774ad4 100644
--- a/lib/logstorage/pipe_rename.go
+++ b/lib/logstorage/pipe_rename.go
@@ -40,7 +40,7 @@ func (pr *pipeRename) updateNeededFields(neededFields, unneededFields fieldsSet)
 	}
 	if neededFields.contains("*") {
 		// update only unneeded fields
-		unneededFields.addAll(pr.dstFields)
+		unneededFields.addFields(pr.dstFields)
 		for i, srcField := range pr.srcFields {
 			if neededSrcFields[i] {
 				unneededFields.remove(srcField)
@@ -50,7 +50,7 @@ func (pr *pipeRename) updateNeededFields(neededFields, unneededFields fieldsSet)
 		}
 	} else {
 		// update only needed fields and reset unneeded fields
-		neededFields.removeAll(pr.dstFields)
+		neededFields.removeFields(pr.dstFields)
 		for i, srcField := range pr.srcFields {
 			if neededSrcFields[i] {
 				neededFields.add(srcField)
diff --git a/lib/logstorage/pipe_uniq.go b/lib/logstorage/pipe_uniq.go
index 757b057a4..be338f656 100644
--- a/lib/logstorage/pipe_uniq.go
+++ b/lib/logstorage/pipe_uniq.go
@@ -40,7 +40,7 @@ func (pu *pipeUniq) updateNeededFields(neededFields, unneededFields fieldsSet) {
 	if len(pu.byFields) == 0 {
 		neededFields.add("*")
 	} else {
-		neededFields.addAll(pu.byFields)
+		neededFields.addFields(pu.byFields)
 	}
 }
 
diff --git a/lib/logstorage/stats_avg.go b/lib/logstorage/stats_avg.go
index 5977a31e3..cdf7d6477 100644
--- a/lib/logstorage/stats_avg.go
+++ b/lib/logstorage/stats_avg.go
@@ -16,7 +16,7 @@ func (sa *statsAvg) String() string {
 }
 
 func (sa *statsAvg) updateNeededFields(neededFields fieldsSet) {
-	neededFields.addAll(sa.fields)
+	neededFields.addFields(sa.fields)
 }
 
 func (sa *statsAvg) newStatsProcessor() (statsProcessor, int) {
diff --git a/lib/logstorage/stats_count.go b/lib/logstorage/stats_count.go
index 158ea0f20..1de39031b 100644
--- a/lib/logstorage/stats_count.go
+++ b/lib/logstorage/stats_count.go
@@ -22,7 +22,7 @@ func (sc *statsCount) updateNeededFields(neededFields fieldsSet) {
 		// There is no need in fetching any columns for count(*) - the number of matching rows can be calculated as len(blockResult.timestamps)
 		return
 	}
-	neededFields.addAll(sc.fields)
+	neededFields.addFields(sc.fields)
 }
 
 func (sc *statsCount) newStatsProcessor() (statsProcessor, int) {
diff --git a/lib/logstorage/stats_count_empty.go b/lib/logstorage/stats_count_empty.go
index c18756a5d..b9916ef24 100644
--- a/lib/logstorage/stats_count_empty.go
+++ b/lib/logstorage/stats_count_empty.go
@@ -18,7 +18,7 @@ func (sc *statsCountEmpty) String() string {
 }
 
 func (sc *statsCountEmpty) updateNeededFields(neededFields fieldsSet) {
-	neededFields.addAll(sc.fields)
+	neededFields.addFields(sc.fields)
 }
 
 func (sc *statsCountEmpty) newStatsProcessor() (statsProcessor, int) {
diff --git a/lib/logstorage/stats_count_uniq.go b/lib/logstorage/stats_count_uniq.go
index 319aad7fc..7ad3af47f 100644
--- a/lib/logstorage/stats_count_uniq.go
+++ b/lib/logstorage/stats_count_uniq.go
@@ -25,7 +25,7 @@ func (su *statsCountUniq) String() string {
 }
 
 func (su *statsCountUniq) updateNeededFields(neededFields fieldsSet) {
-	neededFields.addAll(su.fields)
+	neededFields.addFields(su.fields)
 }
 
 func (su *statsCountUniq) newStatsProcessor() (statsProcessor, int) {
diff --git a/lib/logstorage/stats_max.go b/lib/logstorage/stats_max.go
index 8d1cea099..5eed2e748 100644
--- a/lib/logstorage/stats_max.go
+++ b/lib/logstorage/stats_max.go
@@ -20,7 +20,7 @@ func (sm *statsMax) String() string {
 }
 
 func (sm *statsMax) updateNeededFields(neededFields fieldsSet) {
-	neededFields.addAll(sm.fields)
+	neededFields.addFields(sm.fields)
 }
 
 func (sm *statsMax) newStatsProcessor() (statsProcessor, int) {
diff --git a/lib/logstorage/stats_median.go b/lib/logstorage/stats_median.go
index ac60844a3..baeb240e3 100644
--- a/lib/logstorage/stats_median.go
+++ b/lib/logstorage/stats_median.go
@@ -15,7 +15,7 @@ func (sm *statsMedian) String() string {
 }
 
 func (sm *statsMedian) updateNeededFields(neededFields fieldsSet) {
-	neededFields.addAll(sm.fields)
+	neededFields.addFields(sm.fields)
 }
 
 func (sm *statsMedian) newStatsProcessor() (statsProcessor, int) {
diff --git a/lib/logstorage/stats_min.go b/lib/logstorage/stats_min.go
index bd1baecc4..f82d85e6b 100644
--- a/lib/logstorage/stats_min.go
+++ b/lib/logstorage/stats_min.go
@@ -20,7 +20,7 @@ func (sm *statsMin) String() string {
 }
 
 func (sm *statsMin) updateNeededFields(neededFields fieldsSet) {
-	neededFields.addAll(sm.fields)
+	neededFields.addFields(sm.fields)
 }
 
 func (sm *statsMin) newStatsProcessor() (statsProcessor, int) {
diff --git a/lib/logstorage/stats_quantile.go b/lib/logstorage/stats_quantile.go
index 74b6e0de4..d7ac2352e 100644
--- a/lib/logstorage/stats_quantile.go
+++ b/lib/logstorage/stats_quantile.go
@@ -25,7 +25,7 @@ func (sq *statsQuantile) String() string {
 }
 
 func (sq *statsQuantile) updateNeededFields(neededFields fieldsSet) {
-	neededFields.addAll(sq.fields)
+	neededFields.addFields(sq.fields)
 }
 
 func (sq *statsQuantile) newStatsProcessor() (statsProcessor, int) {
diff --git a/lib/logstorage/stats_sum.go b/lib/logstorage/stats_sum.go
index 23b0d5136..5ca7b082f 100644
--- a/lib/logstorage/stats_sum.go
+++ b/lib/logstorage/stats_sum.go
@@ -17,7 +17,7 @@ func (ss *statsSum) String() string {
 }
 
 func (ss *statsSum) updateNeededFields(neededFields fieldsSet) {
-	neededFields.addAll(ss.fields)
+	neededFields.addFields(ss.fields)
 }
 
 func (ss *statsSum) newStatsProcessor() (statsProcessor, int) {
diff --git a/lib/logstorage/stats_sum_len.go b/lib/logstorage/stats_sum_len.go
index 644a421b5..0b27f45c2 100644
--- a/lib/logstorage/stats_sum_len.go
+++ b/lib/logstorage/stats_sum_len.go
@@ -16,7 +16,7 @@ func (ss *statsSumLen) String() string {
 }
 
 func (ss *statsSumLen) updateNeededFields(neededFields fieldsSet) {
-	neededFields.addAll(ss.fields)
+	neededFields.addFields(ss.fields)
 }
 
 func (ss *statsSumLen) newStatsProcessor() (statsProcessor, int) {
diff --git a/lib/logstorage/stats_uniq_values.go b/lib/logstorage/stats_uniq_values.go
index 9667d5883..4942f1213 100644
--- a/lib/logstorage/stats_uniq_values.go
+++ b/lib/logstorage/stats_uniq_values.go
@@ -25,7 +25,7 @@ func (su *statsUniqValues) String() string {
 }
 
 func (su *statsUniqValues) updateNeededFields(neededFields fieldsSet) {
-	neededFields.addAll(su.fields)
+	neededFields.addFields(su.fields)
 }
 
 func (su *statsUniqValues) newStatsProcessor() (statsProcessor, int) {
diff --git a/lib/logstorage/stats_values.go b/lib/logstorage/stats_values.go
index b7183d45b..dd57a6ddc 100644
--- a/lib/logstorage/stats_values.go
+++ b/lib/logstorage/stats_values.go
@@ -22,7 +22,7 @@ func (sv *statsValues) String() string {
 }
 
 func (sv *statsValues) updateNeededFields(neededFields fieldsSet) {
-	neededFields.addAll(sv.fields)
+	neededFields.addFields(sv.fields)
 }
 
 func (sv *statsValues) newStatsProcessor() (statsProcessor, int) {