title: Why and how hibernate_sequence is using for id generatior
body: <p>I'm faced out an issue with ID generation for my entities generated by JHipster:</p>
  
  <ol>
  <li>Dev environment on H2 database</li>
  <li>Prod environment on Postgres</li>
  <li>I have one entity "station" with two fields "id" and "name"</li>
  <li>Creating a liquibase script which imports dictionary in "station" table like 
  <code>INSERT INTO station (name) VALUES ('Adygeya')</code> without ID definition</li>
  <li>Trying to add station on dev environment - OK</li>
  <li>Trying to add station on prod - Hibernate tries to add new station with duplicated ID</li>
  </ol>
  
  <p>WHY?</p>
  
  <p>My research was shown that only for postgres and oracle in initial scheme jhipster created a new sequince "hibernate_sequence" which is used for new entities creation.</p>
  
  <p>So I'm fixed out this wrong behaivour by adding specific sequence name for my entity ID generation rule </p>
  
  <pre><code>@Id
  @GeneratedValue(strategy = GenerationType.AUTO, generator = "station_gen")
  @SequenceGenerator(name = "station_gen", sequenceName = "station_id_seq")
  private Long id;
  </code></pre>
  
  <p>Now I have just 3 questions:</p>
  
  <ol>
  <li>Why JHipster using one sequince for all tables for postgres and oracle?</li>
  <li>Where is it configured?</li>
  <li>What am I doing wrong? </li>
  </ol>