Currently, if the `hibernate.id.new_generator_mappings` is set to `false`, `@GeneratedValue(strategy = GenerationType.AUTO)` is mapped to `native`. If this property is `true` (which is the deafult value in 5.x), the `@GeneratedValue(strategy = GenerationType.AUTO)` is always mapped to `SequenceStyleGenerator`.

For this reason, on any database that does not support sequences natively (e.g. MySQL) we are going to use the `TABLE` generator instead of `IDENTITY`.

However, `TABLE` generator, although more portable, uses a separate transaction every time a value is being fetched from the database. In fact, even if the `IDENTITY` disables JDBC batch updates and the `TABLE` generator uses the pooled optimizer, the `IDENTITY` still scales better.