Siddon Tang from TiDB here. Thanks for your interest in TiDB!
TiDB uses Snapshot Isolation (https://en.wikipedia.org/wiki/Snapshot_isolation), which is similar to Repeated Read in MySQL. It doesn’t allow Read Phantom but can’t avoid Write Skew. IMO, this can work well for OLTP in most of the cases. If you really care about serializability, you can use `select for update` to promote the Read as Write explicitly like other databases do.
TiDB supports READ COMMITTED isolation which is not the same as MySQL, but it is just designed for some special cases for TiDB itself and it is not recommended for external users.
TiDB supports READ COMMITTED isolation which is not the same as MySQL, but it is just designed for some special cases for TiDB itself and it is not recommended for external users.