title: How does ETL (database to database) fit into SOA?
body: <p>Lets imagine, that our application needs ETL (extract, transform, load) data from relation database to another relation database.
  Most simple (and most performance, IMHO) way is to make link between databases and write simple stored procedure. In this case we use minimal technologies and components, all features are "out of the box".</p>
  
  <p>But is it good practice for SOA (service-oriented architecture)? What about tight coupling? Do we strongly couple the databases to each other for ever?</p>
  
  <p>There is another way to do this: we build 2 java applications in each side and communicate by SOAP web services. This is more SOA friendly! But are the performance degradation and additional points of failure worth it?</p>
  
  <p>What will be the best practice in this case? How can ETL fit within SOA?</p>