title: what does the hibernate cache save?
body: <p>Hi:
  I am confused about what is cached by the hibernate cache.</p>
  
  <p>From the docs, I know there are there types of cache in hibernate.</p>
  
  <p><strong>First-level</strong>:the transaction-level.
  It seems that the entity to be persisted by a session are cached here.</p>
  
  <p><strong>Second-level cache</strong>: I really have no idea about this cache,from the api,it said this cache work at the sessionfactory level... I can not understand.</p>
  
  <p><strong>Query cache</strong>: This is easily understand for me(maybe I am wrong). It cache the query parameter along with the related entity.</p>
  
  <p>This is all I know about the cache in hibernate.</p>
  
  <p>Anyone can give me more details?</p>
  
  <p>BTW,I am not good at the sql/jdbc work,so I also want to know how should I know about the sql/jdbc to learn more about hibernate(any docs?)? I do not want to be just a hibernate user since it is just a tool,what I want is learn something from this wonderful framwork. :)</p>