default nlist 2048 (#2498)

Signed-off-by: Ngroot <yihua.mo@zilliz.com>

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 {

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;

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;