diff --git a/internal/core/src/segcore/SegmentSealedImpl.cpp b/internal/core/src/segcore/SegmentSealedImpl.cpp
index d57097c410..8ba749fb24 100644
--- a/internal/core/src/segcore/SegmentSealedImpl.cpp
+++ b/internal/core/src/segcore/SegmentSealedImpl.cpp
@@ -495,10 +495,16 @@ SegmentSealedImpl::mask_with_timestamps(boost::dynamic_bitset<>& bitset_chunk, T
     // TODO change the
     AssertInfo(this->timestamps_.size() == get_row_count(), "Timestamp size not equal to row count");
     auto range = timestamp_index_.get_active_range(timestamp);
+
+    // range == (size_, size_) and size_ is this->timestamps_.size().
+    // it means these data are all useful, we don't need to update bitset_chunk.
+    // It can be thought of as an AND operation with another bitmask that is all 1s, but it is not necessary to do so.
     if (range.first == range.second && range.first == this->timestamps_.size()) {
         // just skip
         return;
     }
+    // range == (0, 0). it means these data can not be used, directly set bitset_chunk to all 0s.
+    // It can be thought of as an AND operation with another bitmask that is all 0s.
     if (range.first == range.second && range.first == 0) {
         bitset_chunk.reset();
         return;
diff --git a/internal/core/unittest/test_get_entity_by_ids.cpp b/internal/core/unittest/test_get_entity_by_ids.cpp
index 8169510adf..efc72a9379 100644
--- a/internal/core/unittest/test_get_entity_by_ids.cpp
+++ b/internal/core/unittest/test_get_entity_by_ids.cpp
@@ -161,7 +161,8 @@ TEST(Retrieve2, LargeTimestamp) {
 
     int64_t N = 100;
     int64_t req_size = 10;
-    auto choose = [=](int i) { return i * 3 % N; };
+    int choose_sep = 3;
+    auto choose = [=](int i) { return i * choose_sep % N; };
     uint64_t ts_offset = 100;
     auto dataset = DataGen(schema, N, 42, ts_offset + 1);
     auto segment = CreateSealedSegment(schema);
@@ -181,12 +182,20 @@ TEST(Retrieve2, LargeTimestamp) {
     std::vector<FieldOffset> target_offsets{FieldOffset(0), FieldOffset(1)};
     plan->field_offsets_ = target_offsets;
 
-    auto retrieve_results = segment->Retrieve(plan.get(), ts_offset);
-    Assert(retrieve_results->fields_data_size() == 2);
-    auto field0 = retrieve_results->fields_data(0);
-    auto field1 = retrieve_results->fields_data(1);
-    Assert(field0.scalars().long_data().data_size() == 0);
-    Assert(field1.scalars().long_data().data_size() == 0);
+    std::vector<int> filter_timestamps {-1, 0, 1, 10 ,20};
+    filter_timestamps.push_back(N / 2);
+    for (const auto & f_ts: filter_timestamps) {
+        auto retrieve_results = segment->Retrieve(plan.get(), ts_offset + 1 + f_ts);
+        Assert(retrieve_results->fields_data_size() == 2);
+        auto field0 = retrieve_results->fields_data(0);
+        auto field1 = retrieve_results->fields_data(1);
+        int target_num = (f_ts + choose_sep ) / choose_sep;
+        if (target_num >req_size) {
+            target_num = req_size;
+        }
+        Assert(field0.scalars().long_data().data_size() == target_num);
+        Assert(field1.vectors().float_vector().data_size() == target_num * DIM);
+    }
 }
 
 TEST(GetEntityByIds, PrimaryKey) {