openGauss MOT SILO Enhancements

SILO in its basic algorithm flow outperformed many other ACID-compliant OCCs that we tested in our research experiments. However, in order to make it a product-grade mechanism, we had to enhance it with many essential functionalities that were missing in the original design, such as –

• Added support for interactive mode transactions, where transactions are running SQL by SQL from the client side and not as a single step on the server side

• Added optimistic inserts

• Added support for non-unique indexes

• Added support for read-after-write in transactions so that users can see their own changes before they are committed

• Added support for lockless cooperative garbage collection

• Added support for lockless checkpoints

• Added support for fast recovery

• Multi Version Concurrency Control (MVCC) support was added (openGauss 5.0).

Adding these enhancements without breaking the scalable characteristic of the original SILO was very challenging.