diff --git a/milvus_client.py b/milvus_client.py
index 64caf99..6bf7a81 100644
--- a/milvus_client.py
+++ b/milvus_client.py
@@ -52,6 +52,7 @@ class MilvusClient(PyOperator):
             self.kwargs['limit'] = 10
 
         index_params = {
+            'FLAT': {'params': {'nprobe': 10}},
             'IVF_FLAT': {'params': {'nprobe': 10}},
             'IVF_SQ8': {'params': {'nprobe': 10}},
             'IVF_PQ': {'params': {'nprobe': 10}},
@@ -76,6 +77,7 @@ class MilvusClient(PyOperator):
                 self.kwargs['param']['metric_type'] = 'L2'
 
     def __call__(self, query: 'ndarray'):
+        self._collection.load()
         milvus_result = self._collection.search(
             data=[query],
             **self.kwargs