Does TiDB support distributed transactions?

[jinkun]

Yes. The transaction model in TiDB is inspired by Google’s Percolator, a paper published in 2006. It’s mainly a two-phase commit protocol with some practical optimizations. This model relies on a timestamp allocator to assign monotone increasing timestamp for each transaction, so the conflicts can be detected.  Placement Driver works as the timestamp allocator in a TiDB cluster.