Mine

package db4o;

import java.io.Serializable;

import com.db4o.Db4o;
import com.db4o.ObjectContainer;
import com.db4o.ObjectSet;
import com.db4o.config.annotations.Indexed;
import com.db4o.query.Query;

public class PersistenceTest {

  public static void main(String[] args) throws Exception {
//    testbdb();
//    testLucene();
    testdb4o();
  }

  
//  private static void testbdb() throws DatabaseException, UnsupportedEncodingException {
//    long l1 = System.currentTimeMillis();
//
//    EnvironmentConfig envConfig = new EnvironmentConfig();
//    envConfig.setAllowCreate(true);
//    
//    Environment env = new Environment(new File("bdb.database"), envConfig);
//
//    DatabaseConfig dbConfig = new DatabaseConfig();
//    dbConfig.setAllowCreate(true);
//
//    Database db = env.openDatabase(null, "bdb.database", dbConfig); 
//    
//    ClassCatalog catalog = new StoredClassCatalog(db);
//    EntryBinding binding = new SerialBinding(catalog, Simple.class);
//    
//    for (int i = 0; i < 1000; i++) {
//      Simple simple = new Simple("group", "foo " + i, i);
//
//      DatabaseEntry key = new DatabaseEntry(Integer.toString(i).getBytes("UTF-8"));
//      DatabaseEntry data = new DatabaseEntry();
//            
//      binding.objectToEntry(simple, data);
//      
//      db.put(null, key, data);
//    }
//
//    long l2 = System.currentTimeMillis();
//    System.err.println("bdb: " + (l2-l1)/1000f);
//
//    // need to use "secondary database" for retrieving by "group" field
//    for (int i = 0; i < 1000; i++) {
//      DatabaseEntry key = new DatabaseEntry(Integer.toString(i).getBytes("UTF-8"));
//      DatabaseEntry data = new DatabaseEntry();
//            
//      if(db.get(null, key, data, LockMode.DEFAULT)!=OperationStatus.SUCCESS) {
//        System.err.println("Can't find " + i);
//      }
//    }
//    long l3 = System.currentTimeMillis();
//    System.err.println("bdb: " + (l3-l2)/1000f);
//    
//    
//    db.close();
//  }



//  private static void testLucene() throws IOException {
//    IndexWriter w = new IndexWriter("lucene.database", new SimpleAnalyzer(), true);
//    
//    long l1 = System.currentTimeMillis();
//    for (int i = 0; i < 1000; i++) {
//      Document doc = new Document();
//      doc.add(new Field("group", "group", Field.Store.YES, Field.Index.UN_TOKENIZED));
//      doc.add(new Field("foo", "foo " + i, Field.Store.YES, Field.Index.UN_TOKENIZED));
//      doc.add(new Field("n", Integer.toString(i), Field.Store.YES, Field.Index.UN_TOKENIZED));
//      
//      w.updateDocument(new Term("n", Integer.toString(i)), doc);
//    }
//    
//    w.optimize();
//    w.close();
//
//    long l2 = System.currentTimeMillis();
//    System.err.println("lucene: " + (l2-l1)/1000f);
//    
//    IndexReader r = IndexReader.open("lucene.database");
//    IndexSearcher s = new IndexSearcher(r);
//    PhraseQuery q = new PhraseQuery();
//    q.add(new Term("group", "group"));
//    Hits hits = s.search(q);
//
//    if(hits.length()!=1000) {
//      System.err.println("lucene: Invalid search result");
//    }
//
//    long l3 = System.currentTimeMillis();
//    System.err.println("lucene: " + (l3-l2)/1000f);
//  }


  private static void testdb4o() {
	Db4o.configure().flushFileBuffers(false);
    ObjectContainer db = Db4o.openFile("db4o.database");
    
    long l1 = System.currentTimeMillis();
    for (int i = 0; i < 1000; i++) {
      final Simple s = new Simple("group", "foo " + i, i);
    
//      ObjectSet<Simple> set = db.query(new Predicate<Simple>() {
//        public boolean match(Simple s1) {
//          return s1.foo.equals(s.foo) && s1.n==s.n;
//        }}); 
      
      Query query = db.query();
      query.constrain(Simple.class);
      query.descend("n").constrain(s.n);
      ObjectSet set = query.execute();
      
      if(set.hasNext()) {
        db.set(set.next());
      } else {
        db.set(s);
      }
    }
    
    db.commit();
    
    long l2 = System.currentTimeMillis();
    System.err.println("db4o: " + (l2-l1)/1000f);
    
    Query query = db.query();
    query.constrain(Simple.class);
    query.descend("group").constrain("group");//$NON-NLS-1$
    ObjectSet set = query.execute();
//    ObjectSet<Simple> set = db.query(new Predicate<Simple>() {
//        public boolean match(Simple s) {
//          return s.group.equals("group");
//        }
//      });

    if(set.size()!=1000) {
      System.err.println("db4o: Invalid search result " + set.size());
    }
    
    long l3 = System.currentTimeMillis();
    System.err.println("db4o: " + (l3-l2)/1000f);

    db.close();
  }
  
  
  private static final class Simple implements Serializable {
	@Indexed
    String group;
    String foo;
    @Indexed
    int n;

    public Simple(String group, String foo, int n) {
      this.group = group;
      this.foo = foo;
      this.n = n;
    }
  }
  
}