title: Libraries for hash partitioning/Sharding with JPA
body: <p>My department has decided move to hash partitioning/sharding for some of our large Oracle databases.  We will be splitting our entities across different schemas.  I've been tasked to do a spike to evaluate the suitability of different JPA implementations for this.</p>
  
  <p>The two that I've told to focus on are <a href="http://www.eclipse.org/eclipselink/" rel="noreferrer">EclipseLink</a> and Apache <a href="http://openjpa.apache.org/" rel="noreferrer">OpenJPA/Slice</a>.  We have exclusively used Hibernate in the past, but <a href="http://www.hibernate.org/subprojects/shards.html" rel="noreferrer">Hibernate Shards</a> is in beta, and appears no longer be actively developed (last release was in 2007), so we are not considering it.</p>
  
  <p>I will be doing my own evaluation and trial implementations, but I don't trust that I will get a good feel for the overall quality of these implementations in the time that I've been given.  If you are using OpenJPA and/or EclipseLink in a production environment, especially if your database is shareded, I would like to hear about your experiences (positive and negative), your opinions about their overall quality, and if you'd make the same choice again if given the opportunity.</p>