diff --git a/paimon-common/src/main/java/org/apache/paimon/data/serializer/RowCompactedSerializer.java b/paimon-common/src/main/java/org/apache/paimon/data/serializer/RowCompactedSerializer.java
index baa4d0432564..c2a501b7e3cf 100644
--- a/paimon-common/src/main/java/org/apache/paimon/data/serializer/RowCompactedSerializer.java
+++ b/paimon-common/src/main/java/org/apache/paimon/data/serializer/RowCompactedSerializer.java
@@ -735,14 +735,15 @@ private InternalRow readRow(RowCompactedSerializer serializer) {
 
     private static class SliceComparator implements Comparator<MemorySlice> {
 
-        private final RowReader reader1;
-        private final RowReader reader2;
+        private final int headerSizeInBytes;
+        private final ThreadLocal<RowReader> reader1;
+        private final ThreadLocal<RowReader> reader2;
         private final FieldReader[] fieldReaders;
 
         public SliceComparator(RowType rowType) {
-            int bitSetInBytes = calculateBitSetInBytes(rowType.getFieldCount());
-            this.reader1 = new RowReader(bitSetInBytes);
-            this.reader2 = new RowReader(bitSetInBytes);
+            this.headerSizeInBytes = calculateBitSetInBytes(rowType.getFieldCount());
+            this.reader1 = ThreadLocal.withInitial(() -> new RowReader(headerSizeInBytes));
+            this.reader2 = ThreadLocal.withInitial(() -> new RowReader(headerSizeInBytes));
             this.fieldReaders = new FieldReader[rowType.getFieldCount()];
             for (int i = 0; i < rowType.getFieldCount(); i++) {
                 fieldReaders[i] = createFieldReader(rowType.getTypeAt(i));
@@ -751,11 +752,13 @@ public SliceComparator(RowType rowType) {
 
         @Override
         public int compare(MemorySlice slice1, MemorySlice slice2) {
-            reader1.pointTo(slice1.segment(), slice1.offset());
-            reader2.pointTo(slice2.segment(), slice2.offset());
+            RowReader r1 = reader1.get();
+            RowReader r2 = reader2.get();
+            r1.pointTo(slice1.segment(), slice1.offset());
+            r2.pointTo(slice2.segment(), slice2.offset());
             for (int i = 0; i < fieldReaders.length; i++) {
-                boolean isNull1 = reader1.isNullAt(i);
-                boolean isNull2 = reader2.isNullAt(i);
+                boolean isNull1 = r1.isNullAt(i);
+                boolean isNull2 = r2.isNullAt(i);
                 if (!isNull1 || !isNull2) {
                     if (isNull1) {
                         return -1;
@@ -763,8 +766,8 @@ public int compare(MemorySlice slice1, MemorySlice slice2) {
                         return 1;
                     } else {
                         FieldReader fieldReader = fieldReaders[i];
-                        Object o1 = fieldReader.readField(reader1, i);
-                        Object o2 = fieldReader.readField(reader2, i);
+                        Object o1 = fieldReader.readField(r1, i);
+                        Object o2 = fieldReader.readField(r2, i);
                         int comp;
                         if (o1 instanceof byte[]) {
                             // BINARY / VARBINARY fields read back as byte[], which does not