Remove unnecessary bitset flip in Search and Query (#17387)

Signed-off-by: bigsheeper <yihao.dai@zilliz.com>

internal/core/src/query/visitors/ExecPlanNodeVisitor.cpp

@@ -92,11 +92,11 @@ ExecPlanNodeVisitor::VectorVisitorImpl(VectorPlanNode& node) {
     BitsetType bitset_holder;
     if (node.predicate_.has_value()) {
         bitset_holder = ExecExprVisitor(*segment, active_count, timestamp_).call_child(*node.predicate_.value());
+        bitset_holder.flip();
     } else {
-        bitset_holder.resize(active_count, true);
+        bitset_holder.resize(active_count, false);
     }
     segment->mask_with_timestamps(bitset_holder, timestamp_);
-    bitset_holder.flip();
 
     segment->mask_with_delete(bitset_holder, active_count, timestamp_);
     BitsetView final_view = bitset_holder;
@@ -123,10 +123,10 @@ ExecPlanNodeVisitor::visit(RetrievePlanNode& node) {
     BitsetType bitset_holder;
     if (node.predicate_ != nullptr) {
         bitset_holder = ExecExprVisitor(*segment, active_count, timestamp_).call_child(*(node.predicate_));
+        bitset_holder.flip();
     }
 
     segment->mask_with_timestamps(bitset_holder, timestamp_);
-    bitset_holder.flip();
 
     segment->mask_with_delete(bitset_holder, active_count, timestamp_);
     BitsetView final_view = bitset_holder;

internal/core/src/segcore/SegmentSealedImpl.cpp

@@ -775,19 +775,19 @@ SegmentSealedImpl::mask_with_timestamps(BitsetType& bitset_chunk, Timestamp time
 
     // 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.
+    // It can be thought of as an OR operation with another bitmask that is all 0s, but it is not necessary to do so.
     if (range.first == range.second && range.first == timestamps_data.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.
+    // range == (0, 0). it means these data can not be used, directly set bitset_chunk to all 1s.
+    // It can be thought of as an OR operation with another bitmask that is all 1s.
     if (range.first == range.second && range.first == 0) {
-        bitset_chunk.reset();
+        bitset_chunk.set();
         return;
     }
     auto mask = TimestampIndex::GenerateBitset(timestamp, range, timestamps_data.data(), timestamps_data.size());
-    bitset_chunk &= mask;
+    bitset_chunk |= mask;
 }
 
 }  // namespace milvus::segcore

internal/core/src/segcore/TimestampIndex.cpp

@@ -72,10 +72,10 @@ TimestampIndex::GenerateBitset(Timestamp query_timestamp,
     Assert(beg < end);
     BitsetType bitset;
     bitset.reserve(size);
-    bitset.resize(beg, true);
-    bitset.resize(size, false);
+    bitset.resize(beg, false);
+    bitset.resize(size, true);
     for (int64_t i = beg; i < end; ++i) {
-        bitset[i] = timestamps[i] <= query_timestamp;
+        bitset[i] = timestamps[i] > query_timestamp;
     }
     return bitset;
 }