New Foreign Keys in 6.1

A new standard conforming and engine-neutral implementation of foreign keys is being developed for 6.1 version of server.

During this session we will cover features supported by this new implementation such as column references, recursive relationships and checks done as if they happen at the end of statement.

We will also discuss how different levels of foreign key support depend on engine capabilities (e.g. we will look at differences between transactional and non-transactional engines).

Then we will compare new and old, InnoDB-specific implementation and discuss the migration process and possible issues which may arise during it.

Next thing we will look at is performance impact of new foreign keys (as compared to case when there are no foreign keys and case when one has old foreign keys).

Finally we will discuss possible future development in this area such as possible optimizations of foreign key checks and support of foreign keys for distributed engines (NDB or Federated).