diff --git a/core/src/db/Types.h b/core/src/db/Types.h
index 0f25dff82c30ed92d34ef0991a9a72da0f38164d..c16235301798c31f86bcd99f04895ae601e926ce 100644
--- a/core/src/db/Types.h
+++ b/core/src/db/Types.h
@@ -38,7 +38,7 @@ typedef std::vector<faiss::Index::distance_t> ResultDistances;
 struct CollectionIndex {
     int32_t engine_type_ = (int)EngineType::FAISS_IDMAP;
     int32_t metric_type_ = (int)MetricType::L2;
-    milvus::json extra_params_ = {{"nlist", 16384}};
+    milvus::json extra_params_ = {{"nlist", 2048}};
 };
 
 struct VectorsData {
diff --git a/core/src/db/meta/MetaTypes.h b/core/src/db/meta/MetaTypes.h
index fff6d74abe77e673cde0ff1352ae6e73fe6d1100..e98876903072289df3892d59a6612c042aae4ce6 100644
--- a/core/src/db/meta/MetaTypes.h
+++ b/core/src/db/meta/MetaTypes.h
@@ -25,7 +25,6 @@ namespace engine {
 namespace meta {
 
 constexpr int32_t DEFAULT_ENGINE_TYPE = (int)EngineType::FAISS_IDMAP;
-constexpr int32_t DEFAULT_NLIST = 16384;
 constexpr int32_t DEFAULT_METRIC_TYPE = (int)MetricType::L2;
 constexpr int32_t DEFAULT_INDEX_FILE_SIZE = GB;
 constexpr char CURRENT_VERSION[] = MILVUS_VERSION;
diff --git a/core/src/utils/ValidationUtil.cpp b/core/src/utils/ValidationUtil.cpp
index 714157148db6e3cb1964396a8bf611b87385f9f5..caa4e21a3653ba84ba218a71a49f1690bfc08918 100644
--- a/core/src/utils/ValidationUtil.cpp
+++ b/core/src/utils/ValidationUtil.cpp
@@ -112,7 +112,7 @@ ValidationUtil::ValidateCollectionName(const std::string& collection_name) {
     }
 
     std::string invalid_msg = "Invalid collection name: " + collection_name + ". ";
-    // Collection name size shouldn't exceed 16384.
+    // Collection name size shouldn't exceed 255.
     if (collection_name.size() > COLLECTION_NAME_SIZE_LIMIT) {
         std::string msg = invalid_msg + "The length of a collection name must be less than 255 characters.";
         LOG_SERVER_ERROR_ << msg;
@@ -426,7 +426,7 @@ ValidationUtil::ValidatePartitionName(const std::string& partition_name) {
     }
 
     std::string invalid_msg = "Invalid partition name: " + partition_name + ". ";
-    // Collection name size shouldn't exceed 16384.
+    // Collection name size shouldn't exceed 255.
     if (partition_name.size() > COLLECTION_NAME_SIZE_LIMIT) {
         std::string msg = invalid_msg + "The length of a partition name must be less than 255 characters.";
         LOG_SERVER_ERROR_ << msg;