anchor.diff:  * performance improvement process (see JPT)
   ** no premature optimization
   ** have a performance objective
  +** concentrate of the 20% of the app that is responsible for 80% of the load
  +** one issue often hides other issues
  +** first actions might not show any improvement. Yet, don't despair!
   ** test in real-life conditions (DB size, # simultaneous users, server sizing...)
   ** OS contention, then GC issues, then code optimization
   ** ...
  
positive.code: *** replace Lists and Strings by arrays
  *** cryptography is slow
  *** XML parsing is slow
  *** serializin/deserializing is slow
  *** creating a regexp is slow
  *** prefer StringBuilder over String.format
  *** avoid polling
  
negative.code:  http://howtodoinjava.com/core-java/jdbc/best-practices-to-improve-jdbc-performance/
   http://www.javaperformancetuning.com/tips/jdbc_prepared.shtml
   http://www.javaperformancetuning.com/tips/rawtips.shtml >> http://www.as400.ibm.com/developer/java/topics/jdbctips.html
  *** Use +PreparedStatement+, parameters *must* be injected through bind variables
  *** use batch mode when applicable
  *** avoid multiple joins (highly non-linear!)
  *** Use optimistic transactions
  