title: Why use Elasticsearch or Apache Solr along with Hibernate Search?
body: <p>I learned and understood that Elasticsearch, Apache Solr and Hibernate Search are based on the Apache Lucene library. They provide fast full-text search and all of them either use JPA annotations, implement the JPA and/or define custom annotations. They are mostly used in addition to RDBMS/NoSQL data storage. The indexed and searchable data is present in the form of documents.</p>
  
  <p>I am totally okay that someone poses the question <a href="https://stackoverflow.com/questions/6068831/solr-vs-hibernate-search-which-to-choose-and-when">Solr vs Hibernate Search - Which to choose and When?</a> or even 'Elasticsearch vs Solr' or 'Elasticsearch vs Hibernate Search'
  But then there is this <a href="https://github.com/55social/hibernate-search-elasticsearch-connector" rel="nofollow noreferrer">Hibernate Search/Elasticsearch connector</a> as an approach to use Hibernate Search <em>and</em> Elasticsearch alongside or <a href="https://stackoverflow.com/questions/13918211/how-to-integrate-hibernate-and-solr-together">this post</a> asking "How to integrate Hibernate and Solr together?" with the answer how to integrate Hibernate Search and Solr together, which for me is something different, right?</p>
  
  <p>Assuming the above summary is correct and given the linked posts confused me: Why do people consider to or do use Elasticsearch or Solr in addition to Hibernate Search? Isn't this redundant? Or does Hibernate <em>Search</em> provide any interface for Solr/Elasticsearch which Hibernate <em>ORM</em> does not and thus is only used as some sort of adapter?</p>