Sequence generator with PlayFramework, JPA, and PostgreSQL

I have been recently making some websites using PlayFramework but has just noticed something about auto-generated Id number behavior when using PostgreSQL as database.

I usually create a Model (which is a JPA entity) by extending play.db.jpa.Model which actually have an auto generated Id property and a lot of very useful database related operations. PostgreSQL uses sequence for auto-generated number. By extending the play.db.jpa.Model, you actually use only one sequence generator for all your models. Thats making my first insert to a table (second or so, if you have more than one table) does not always start from 1.

I then decided to use one sequence per table by doing this following changes:
1. Extends play.db.jpa.GenericModel instead
2. Add an Id property to each model class

@Entity
public class Token extends GenericModel {

  @Id
  @SequenceGenerator(name = "Token_generator", sequenceName = "Token_sequence")
  @GeneratedValue(generator = "Token_generator")
  public Long id;

  ...omitted...

3. Recreate all the table

This happens only when you are using sequence as number generator (PostgreSQL and Oracle AFAIK?), MySQL should not have this kind of behavior because MySQL use AUTO_INCREMENT instead of sequence generator.