diff --git a/README.md b/README.md
index 8a3e3667..7f7f48e1 100644
--- a/README.md
+++ b/README.md
@@ -420,15 +420,16 @@ _Libraries for connecting and operating databases._
 
 ### Database
 
-_Databases implemented in Python._
+_In-process databases usable directly from Python._
 
-- [chdb](https://github.com/chdb-io/chdb) - In-process OLAP SQL engine with the full ClickHouse dialect, zero-copy pandas/Arrow interop, and federation to remote ClickHouse clusters via `remoteSecure()`.
-- [chromadb](https://github.com/chroma-core/chroma) - An open-source embedding database for building AI applications with embeddings and semantic search.
-- [duckdb](https://github.com/duckdb/duckdb) - An in-process SQL OLAP database management system; optimized for analytics and fast queries, similar to SQLite but for analytical workloads.
-- [pickledb](https://github.com/patx/pickledb) - A simple and lightweight key-value store for Python.
-- [tinydb](https://github.com/msiemens/tinydb) - A tiny, document-oriented database.
-- [ZODB](https://github.com/zopefoundation/ZODB) - A native object database for Python. A key-value and object graph database.
-- [zvec](https://github.com/alibaba/zvec) - An embedded vector database for on-device RAG and edge AI, the SQLite of vector databases.
+- Analytical
+  - [duckdb](https://github.com/duckdb/duckdb) - An in-process SQL OLAP database management system; optimized for analytics and fast queries, similar to SQLite but for analytical workloads.
+  - [chdb](https://github.com/chdb-io/chdb) - In-process OLAP SQL engine with the full ClickHouse dialect, zero-copy pandas/Arrow interop, and federation to remote ClickHouse clusters via `remoteSecure()`.
+- Vector
+  - [chromadb](https://github.com/chroma-core/chroma) - An open-source embedding database for building AI applications with embeddings and semantic search.
+  - [zvec](https://github.com/alibaba/zvec) - An embedded vector database for on-device RAG and edge AI, the SQLite of vector databases.
+- Key-Value & Document
+  - [tinydb](https://github.com/msiemens/tinydb) - A tiny, document-oriented database.
 
 ### Caching