diff --git a/core/src/scheduler/task/SearchTask.cpp b/core/src/scheduler/task/SearchTask.cpp
index 5e71b803e1..857965dd2d 100644
--- a/core/src/scheduler/task/SearchTask.cpp
+++ b/core/src/scheduler/task/SearchTask.cpp
@@ -266,14 +266,19 @@ XSearchTask::Execute() {
 
             // step 3: pick up topk result
             auto spec_k = file_->row_count_ < topk ? file_->row_count_ : topk;
+            if (spec_k == 0) {
+                ENGINE_LOG_WARNING << "Searching in an empty file. file location = " << file_->location_;
+            }
 
             {
                 std::unique_lock<std::mutex> lock(search_job->mutex());
 
-                if (search_job->GetResultIds().front() == -1 && search_job->GetResultIds().size() > spec_k) {
-                    // initialized results set
-                    search_job->GetResultIds().resize(spec_k);
-                    search_job->GetResultDistances().resize(spec_k);
+                if (search_job->GetResultIds().size() > spec_k) {
+                    if (search_job->GetResultIds().front() == -1) {
+                        // initialized results set
+                        search_job->GetResultIds().resize(spec_k * nq);
+                        search_job->GetResultDistances().resize(spec_k * nq);
+                    }
                 }
 
                 XSearchTask::MergeTopkToResultSet(output_ids, output_distance, spec_k, nq, topk, ascending_reduce,