Update env.example

env.example

@@ -108,11 +108,28 @@ EMBEDDING_BINDING_HOST=http://localhost:11434
 # AZURE_EMBEDDING_ENDPOINT=your_endpoint
 # AZURE_EMBEDDING_API_KEY=your_api_key
 
+###########################
 ### Data storage selection
+###########################
+### PostgreSQL
 # LIGHTRAG_KV_STORAGE=PGKVStorage
-# LIGHTRAG_VECTOR_STORAGE=PGVectorStorage
 # LIGHTRAG_DOC_STATUS_STORAGE=PGDocStatusStorage
+# LIGHTRAG_VECTOR_STORAGE=PGVectorStorage
+# LIGHTRAG_GRAPH_STORAGE=PGGraphStorage
+### MongoDB
+# LIGHTRAG_KV_STORAGE=MongoKVStorage
+# LIGHTRAG_DOC_STATUS_STORAGE=MongoDocStatusStorage
+# LIGHTRAG_VECTOR_STORAGE=MongoVectorDBStorage
+# LIGHTRAG_GRAPH_STORAGE=MongoGraphStorage
+### KV Storage
+# LIGHTRAG_KV_STORAGE=RedisKVStorage
+# LIGHTRAG_DOC_STATUS_STORAGE=RedisDocStatusStorage
+### Vector Storage
+LIGHTRAG_VECTOR_STORAGE=FaissVectorDBStorage
+# LIGHTRAG_VECTOR_STORAGE=MilvusVectorDBStorage
+### Graph Storage
 # LIGHTRAG_GRAPH_STORAGE=Neo4JStorage
+# LIGHTRAG_GRAPH_STORAGE=MemgraphStorage
 
 ### PostgreSQL Configuration
 POSTGRES_HOST=localhost