Simple, fast, and extensible database system prototypes.

What's VanillaDB?

VanillaDB is a collection of simple-to-read, fast, and extensible database system components aiming to lower the barrier of new-system prototyping and/or learning the database internals.

Most relational database systems today are too complicated for practitioners, especially newcomers, to leverage and build creative systems/components upon. One main problem is that these systems have been optimized for decades, thus the source code is highly sophisticated and hard to understand. VanillaDB rewrites some key components of a distributed relational database system with the following goals in mind:

  • Simplicity: clean code (written in Java), intuitive APIs, and well-documented internals even your grandma can understand;
  • Performance: simple, but not the simplest, algorithms that deliver reasonable performance;
  • Extensibility: modular architecture that eases the modification, enhancement/pruning, and development of new systems.

The source code of VanillaDB is released under the Apache 2.0 license. And we are happy to hear your feedback or feature requests at

Target Audience

VanillaDB is ideal for:

  • Database researchers who want to validate new algorithms on a real database system or to design a new system;
  • Instructors who want their students to grasp solid knowledge about the internals of a database system and ability to make changes.

For instructors, we offer extra coding labs that help students get hands-on experience in some important modules (e.g., query planning, transaction processing, etc.). Please contact for more details.

VanillaDB has been used as a testbed in some research work (e.g., T-Part in Proc. of SIGMOD’16) and teaching materials in some DB courses (e.g., the “Cloud Database Systems” offered by National Tsing Hua University, Taiwan). It also serves as the core engine in some advanced systems (e.g., ElaSQL, a deterministic, distributed relational databases systems for OLTP workloads).


Currently, VanillaDB consists of two sub-projects, namely the VanillaCore and VanillaComm. The former is a single-node relational database engine and the latter provides the group communication primitives for distributed database systems.

Get VanillaCore
Get VanillaComm

A new sub-project called VanillaBench is on the way.


To cite VanillaDB, please add the following to your BibTex:

  title={T-Part: Partitioning of Transactions for Forward-Pushing in Deterministic Database Systems},
  author={Shan-Hung Wu and Tsai-Yu Feng and Meng-Kai Liao and Shao-Kan Pi and Yu-Shan Lin},
  booktitle={Proceedings of the 2016 ACM SIGMOD International Conference on Management of Data (SIGMOD)},


VanillaCore is a single node, multi-threaded relational database engine that partially supports the SQL-92 standard and offers connectivity via JDBC, embedding, or (Java-based) stored procedures.


VanillaCore Architecture


  • Getting started
    • Configurations, command line interpreter, etc.
  • Background
    • Why relational database systems? ER- and relational-models, transactions and logical schema design and normal forms, etc.
  • Architecture overview and interfaces
    • Client-server interfaces, embedding, storage interfaces, etc.
  • Query engine
    • Server and threads

      Threads v.s. connections v.s. transactions, thread-local v.s. thread-safe components, etc.

    • Query Processing

      SQL parsing and validation, planning, algebra, plan/scan trees, etc.

  • Storage
  • Transaction management
    • Concurrency

      Strict Two-Phase Locking (S2PL), deadlock detection/avoidance, lock granularity, phantom, isolation levels, etc.

    • Recovery

      Physical logging, transaction rollback, UNDO-only recovery, UNDO-REDO recovery, logical logging, physiological logging, ARIES, checkpointing, etc.

  • Efficient query processing
    • Indexing

      Hash and B-tree indexing, index locking, etc.

    • Materialization and sorting (TBA)
    • Effective buffer utilization (TBA)
    • Query optimization (TBA)


VanillaComm is a collection of reliable group communication primitives (e.g., total-ordering) that can benefit the distributed database systems (e.g., eager-replication, NewSQL database systems). It is based on the Appia framework and handles node/machine failure transparently.

Primitives and Stakes


  • Getting started
    • Configurations, applications, etc.
  • Appia
    • Layers, sessions, Qos, channel, etc.
  • Basic abstraction
    • Perfect point-to-point link, perfect failure detection, etc.
  • Reliable Broadcast
    • Best-effort broadcast, reliable broadcast, uniform reliable broadcast, etc.
  • Consensus
    • Flooding consensus, sequencer-based consensus, Paxos, etc.
  • Total-ordering
    • Consensus-based total-ordering, Zab, etc.


VanillaBench eases the database system benchmarking by partially implementing some common benchmarks (e.g., TPC-C, TPC-E, or YCSB). Coming soon.


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Please contact if you have any question.