Hi Knut, thanks for the quick response! I am looking into "Add all data in XPlain tables into the XML file generated by PlanExporter Tool" (https://issues.apache.org/jira/browse/DERBY-4783) improvement, and I felt that it will be really inefficient to use large number of "int Enum patterns"[1] and case statements. So that is why I am wondering whether it is ok to use "*Typesafe Enum* pattern**"[1] in PlanExporter.
I really appreciate your valuable opinion on this to proceed with this improvement! Thanks! [1] http://download.oracle.com/javase/1.5.0/docs/guide/language/enums.html On Fri, Jan 14, 2011 at 6:33 PM, Knut Anders Hatlen <[email protected]> wrote: > > Nirmal Fernando <[email protected]> writes: > > > Hi All, > > > > Is there away to use "enums" in Derby, I mean is it possible to say > > Ant to avoid using Java 1.4 for compiling classes where enums are > > used, and use Java 1.5 instead? > > Hi Nirmal, > > It is possible. See for example > java/testing/org/apache/derbyTesting/functionTests/util/build.xml and > java/engine/org/apache/derby/impl/services/build.xml which contain javac > targets with source and target level set to 1.5: > > <javac > source="1.5" > target="1.5" > ... > > The classes that are compiled this way can only be used on a Java 1.5 or > higher VM, so this technique cannot be used in core functionality unless > an alternative implementation that works on Java 1.4 is provided. For > example, we have a lock manager implementation that depends on > java.util.concurrent.ConcurrentHashMap for performance reasons, but > since ConcurrentHashMap is only available on Java 1.5 and higher, we use > another implementation that's based on java.util.HashMap on older > platforms. > > -- > Knut Anders -- Best Regards, Nirmal C.S.Nirmal J. Fernando Department of Computer Science & Engineering, Faculty of Engineering, University of Moratuwa, Sri Lanka. Blog: http://nirmalfdo.blogspot.com/
