diff --git a/source/net/yacy/kelondro/index/BinSearch.java b/source/net/yacy/kelondro/index/BinSearch.java
index 1afe1b671..b56772764 100644
--- a/source/net/yacy/kelondro/index/BinSearch.java
+++ b/source/net/yacy/kelondro/index/BinSearch.java
@@ -30,7 +30,7 @@ import net.yacy.kelondro.order.ByteOrder;
 import net.yacy.kelondro.order.NaturalOrder;
 
 
-public class BinSearch {
+public final class BinSearch {
     
     private final byte[] chunks;
     private final int    chunksize;
@@ -43,11 +43,11 @@ public class BinSearch {
         this.count = chunks.length / chunksize;
     }
     
-    public boolean contains(final byte[] t) {
+    public final boolean contains(final byte[] t) {
         return contains(t, 0, this.count);
     }
 
-    private synchronized boolean contains(final byte[] t, final int beginPos, final int endPos) {
+    private final synchronized boolean contains(final byte[] t, final int beginPos, final int endPos) {
         // the endPos is exclusive, beginPos is inclusive
         // this method is synchronized to make the use of the buffer possible
         assert t.length == this.chunksize;
@@ -61,11 +61,11 @@ public class BinSearch {
         return false;
     }
     
-    public int size() {
+    public final int size() {
         return count;
     }
     
-    public byte[] get(final int element) {
+    public final byte[] get(final int element) {
         final byte[] a = new byte[chunksize];
         System.arraycopy(this.chunks, element * this.chunksize, a, 0, chunksize);
         return a;
diff --git a/source/net/yacy/kelondro/index/Cache.java b/source/net/yacy/kelondro/index/Cache.java
index 2e528fae5..7da6aa7a7 100644
--- a/source/net/yacy/kelondro/index/Cache.java
+++ b/source/net/yacy/kelondro/index/Cache.java
@@ -41,7 +41,7 @@ import net.yacy.kelondro.order.CloneableIterator;
 import net.yacy.kelondro.util.MemoryControl;
 
 
-public class Cache implements ObjectIndex, Iterable<Row.Entry> {
+public final class Cache implements ObjectIndex, Iterable<Row.Entry> {
 
     // this is a combined read cache and write buffer
     // we maintain four tables:
@@ -91,15 +91,15 @@ public class Cache implements ObjectIndex, Iterable<Row.Entry> {
         return index.row().objectsize;
     }
     
-    public int writeBufferSize() {
+    public final int writeBufferSize() {
         return 0;
     }
     
-    public static long getMemStopGrow() {
+    public final static long getMemStopGrow() {
         return memStopGrow ;
     }
     
-    public static long getMemStartShrink() {
+    public final static long getMemStartShrink() {
         return memStartShrink ;
     }
     
@@ -148,7 +148,7 @@ public class Cache implements ObjectIndex, Iterable<Row.Entry> {
      * checks for space in the miss cache
      * @return true if it is allowed to write into this cache
      */
-    private boolean checkMissSpace() {
+    private final boolean checkMissSpace() {
         // returns true if it is allowed to write into this cache
         if (readMissCache == null) return false;
         long available = MemoryControl.available();
@@ -163,7 +163,7 @@ public class Cache implements ObjectIndex, Iterable<Row.Entry> {
      * checks for space in the hit cache
      * @return true if it is allowed to write into this cache
      */
-    private boolean checkHitSpace() {
+    private final boolean checkHitSpace() {
         // returns true if it is allowed to write into this cache
         if (readHitCache == null) return false;
         long available = MemoryControl.available();
@@ -174,18 +174,18 @@ public class Cache implements ObjectIndex, Iterable<Row.Entry> {
         return (available - 2 * 1024 * 1024 > readHitCache.memoryNeededForGrow());
     }
     
-    public synchronized void clearCache() {
+    public final synchronized void clearCache() {
         if (readMissCache != null) readMissCache.clear();
         if (readHitCache != null) readHitCache.clear();
     }
     
-    public synchronized void close() {
+    public final synchronized void close() {
         index.close();
         readHitCache = null;
         readMissCache = null;
     }
 
-    public synchronized boolean has(final byte[] key) {
+    public final synchronized boolean has(final byte[] key) {
         // first look into the miss cache
         if (readMissCache != null) {
             if (readMissCache.get(key) == null) {
@@ -209,7 +209,7 @@ public class Cache implements ObjectIndex, Iterable<Row.Entry> {
         return index.has(key);
     }
     
-    public synchronized Row.Entry get(final byte[] key) throws IOException {
+    public final synchronized Row.Entry get(final byte[] key) throws IOException {
         // first look into the miss cache
         if (readMissCache != null) {
             if (readMissCache.get(key) == null) {
@@ -250,7 +250,7 @@ public class Cache implements ObjectIndex, Iterable<Row.Entry> {
         return entry;
     }
 
-    public synchronized void put(final Row.Entry row) throws IOException {
+    public final synchronized void put(final Row.Entry row) throws IOException {
         assert (row != null);
         assert (row.columns() == row().columns());
         //assert (!(serverLog.allZero(row.getColBytes(index.primarykey()))));
@@ -280,7 +280,7 @@ public class Cache implements ObjectIndex, Iterable<Row.Entry> {
         }
     }
     
-    public synchronized Row.Entry replace(final Row.Entry row) throws IOException {
+    public final synchronized Row.Entry replace(final Row.Entry row) throws IOException {
         assert (row != null);
         assert (row.columns() == row().columns());
         //assert (!(serverLog.allZero(row.getColBytes(index.primarykey()))));
@@ -313,7 +313,7 @@ public class Cache implements ObjectIndex, Iterable<Row.Entry> {
         return entry;
     }
 
-    public synchronized void addUnique(final Row.Entry row) throws IOException {
+    public final synchronized void addUnique(final Row.Entry row) throws IOException {
         assert (row != null);
         assert (row.columns() == row().columns());
         //assert (!(serverLog.allZero(row.getColBytes(index.primarykey()))));
@@ -342,7 +342,7 @@ public class Cache implements ObjectIndex, Iterable<Row.Entry> {
         }
     }
 
-    public synchronized void addUnique(final Row.Entry row, final Date entryDate) throws IOException {
+    public final synchronized void addUnique(final Row.Entry row, final Date entryDate) throws IOException {
         if (entryDate == null) {
             addUnique(row);
             return;
@@ -368,17 +368,17 @@ public class Cache implements ObjectIndex, Iterable<Row.Entry> {
         }
     }
     
-    public synchronized void addUnique(final List<Row.Entry> rows) throws IOException {
+    public final synchronized void addUnique(final List<Row.Entry> rows) throws IOException {
         final Iterator<Row.Entry> i = rows.iterator();
         while (i.hasNext()) addUnique(i.next());
     }
 
-    public synchronized ArrayList<RowCollection> removeDoubles() throws IOException {
+    public final synchronized ArrayList<RowCollection> removeDoubles() throws IOException {
         return index.removeDoubles();
         // todo: remove reported entries from the cache!!!
     }
     
-    public synchronized Row.Entry remove(final byte[] key) throws IOException {
+    public final synchronized Row.Entry remove(final byte[] key) throws IOException {
         checkMissSpace();
         
         // add entry to miss-cache
@@ -407,7 +407,7 @@ public class Cache implements ObjectIndex, Iterable<Row.Entry> {
         return index.remove(key);
     }
 
-    public synchronized Row.Entry removeOne() throws IOException {
+    public final synchronized Row.Entry removeOne() throws IOException {
         
         checkMissSpace();
         
@@ -425,19 +425,19 @@ public class Cache implements ObjectIndex, Iterable<Row.Entry> {
         return entry;
     }
 
-    public synchronized Row row() {
+    public final synchronized Row row() {
         return index.row();
     }
 
-    public synchronized CloneableIterator<byte[]> keys(final boolean up, final byte[] firstKey) throws IOException {
+    public final synchronized CloneableIterator<byte[]> keys(final boolean up, final byte[] firstKey) throws IOException {
         return index.keys(up, firstKey);
     }
 
-    public synchronized CloneableIterator<Row.Entry> rows(final boolean up, final byte[] firstKey) throws IOException {
+    public final synchronized CloneableIterator<Row.Entry> rows(final boolean up, final byte[] firstKey) throws IOException {
         return index.rows(up, firstKey);
     }
 
-    public Iterator<Entry> iterator() {
+    public final Iterator<Entry> iterator() {
         try {
             return rows();
         } catch (IOException e) {
@@ -445,24 +445,24 @@ public class Cache implements ObjectIndex, Iterable<Row.Entry> {
         }
     }
     
-    public synchronized CloneableIterator<Row.Entry> rows() throws IOException {
+    public final synchronized CloneableIterator<Row.Entry> rows() throws IOException {
         return index.rows();
     }
 
-    public int size() {
+    public final int size() {
         return index.size();
     }
 
-    public String filename() {
+    public final String filename() {
         return index.filename();
     }
 
-    public void clear() throws IOException {
+    public final void clear() throws IOException {
         this.index.clear();
         init();
     }
 
-    public void deleteOnExit() {
+    public final void deleteOnExit() {
         this.index.deleteOnExit();
     }
 
diff --git a/source/net/yacy/kelondro/index/Column.java b/source/net/yacy/kelondro/index/Column.java
index f00119177..3b7672e5d 100644
--- a/source/net/yacy/kelondro/index/Column.java
+++ b/source/net/yacy/kelondro/index/Column.java
@@ -29,7 +29,7 @@ package net.yacy.kelondro.index;
 
 import net.yacy.kelondro.util.kelondroException;
 
-public class Column {
+public final class Column {
 
     public static final int celltype_undefined  = 0;
     public static final int celltype_boolean    = 1;
@@ -192,7 +192,7 @@ public class Column {
         }
     }
 
-    public String toString() {
+    public final String toString() {
         final StringBuilder s = new StringBuilder();
         switch (celltype) {
         case celltype_undefined:
@@ -245,7 +245,7 @@ public class Column {
 	 * @see java.lang.Object#hashCode()
 	 */
 	@Override
-	public int hashCode() {
+	public final int hashCode() {
 		final int prime = 31;
 		int result = 1;
 		result = prime * result + celltype;
@@ -260,7 +260,7 @@ public class Column {
 	 * @see java.lang.Object#equals(java.lang.Object)
 	 */
 	@Override
-	public boolean equals(Object obj) {
+	public final boolean equals(Object obj) {
 		if (this == obj)
 			return true;
 		if (obj == null)
diff --git a/source/net/yacy/kelondro/index/ConcurrentARC.java b/source/net/yacy/kelondro/index/ConcurrentARC.java
index a44035d2f..7a23c214a 100644
--- a/source/net/yacy/kelondro/index/ConcurrentARC.java
+++ b/source/net/yacy/kelondro/index/ConcurrentARC.java
@@ -34,11 +34,10 @@ package net.yacy.kelondro.index;
  * at the same size.
  */
 
-public class ConcurrentARC<K, V> implements ARC<K, V> {
+public final class ConcurrentARC<K, V> implements ARC<K, V> {
 
-    protected int cacheSize;
     private int mask;
-    private ARC<K, V> arc[];
+    private final ARC<K, V> arc[];
     
     @SuppressWarnings("unchecked")
 	public ConcurrentARC(final int cacheSize, int partitions) {
@@ -54,7 +53,7 @@ public class ConcurrentARC<K, V> implements ARC<K, V> {
      * @param s
      * @param v
      */
-    public void put(K s, V v) {
+    public final void put(K s, V v) {
     	this.arc[s.hashCode() & mask].put(s, v);
     }
     
@@ -63,7 +62,7 @@ public class ConcurrentARC<K, V> implements ARC<K, V> {
      * @param s
      * @return the value
      */
-    public V get(K s) {
+    public final V get(K s) {
     	return this.arc[s.hashCode() & mask].get(s);
     }
     
@@ -72,7 +71,7 @@ public class ConcurrentARC<K, V> implements ARC<K, V> {
      * @param s
      * @return
      */
-    public boolean containsKey(K s) {
+    public final boolean containsKey(K s) {
     	return this.arc[s.hashCode() & mask].containsKey(s);
     }
     
@@ -81,14 +80,14 @@ public class ConcurrentARC<K, V> implements ARC<K, V> {
      * @param s
      * @return the old value
      */
-    public V remove(K s) {
+    public final V remove(K s) {
     	return this.arc[s.hashCode() & mask].remove(s);
     }
     
     /**
      * clear the cache
      */
-    public void clear() {
+    public final void clear() {
     	for (ARC<K, V> a: this.arc) a.clear();
     }
 }
diff --git a/source/net/yacy/kelondro/index/HandleMap.java b/source/net/yacy/kelondro/index/HandleMap.java
index 5388ff85d..520e0855d 100644
--- a/source/net/yacy/kelondro/index/HandleMap.java
+++ b/source/net/yacy/kelondro/index/HandleMap.java
@@ -48,7 +48,7 @@ import net.yacy.kelondro.order.ByteOrder;
 import net.yacy.kelondro.order.CloneableIterator;
 
 
-public class HandleMap implements Iterable<Row.Entry> {
+public final class HandleMap implements Iterable<Row.Entry> {
     
     private   final Row rowdef;
     protected ObjectIndexCache index;
@@ -92,7 +92,7 @@ public class HandleMap implements Iterable<Row.Entry> {
         assert this.index.size() == file.length() / (keylength + idxbytes);
     }
     
-    public int[] saturation() {
+    public final int[] saturation() {
     	int keym = 0;
     	int valm = this.rowdef.width(1);
     	int valc;
@@ -116,7 +116,7 @@ public class HandleMap implements Iterable<Row.Entry> {
     	return new int[]{keym, this.rowdef.width(1) - valm};
     }
 
-    private int eq(byte[] a, byte[] b) {
+    private final int eq(byte[] a, byte[] b) {
     	for (int i = 0; i < a.length; i++) {
     		if (a[i] != b[i]) return i;
     	}
@@ -130,7 +130,7 @@ public class HandleMap implements Iterable<Row.Entry> {
      * @return the number of written entries
      * @throws IOException
      */
-    public int dump(File file) throws IOException {
+    public final int dump(File file) throws IOException {
         // we must use an iterator from the combined index, because we need the entries sorted
         // otherwise we could just write the byte[] from the in kelondroRowSet which would make
         // everything much faster, but this is not an option here.
@@ -151,35 +151,35 @@ public class HandleMap implements Iterable<Row.Entry> {
         return c;
     }
 
-    public Row row() {
+    public final Row row() {
         return index.row();
     }
     
-    public void clear() {
+    public final void clear() {
         index.clear();
     }
     
-    public synchronized byte[] smallestKey() {
+    public final synchronized byte[] smallestKey() {
         return index.smallestKey();
     }
     
-    public synchronized byte[] largestKey() {
+    public final synchronized byte[] largestKey() {
         return index.largestKey();
     }
     
-    public synchronized boolean has(final byte[] key) {
+    public final synchronized boolean has(final byte[] key) {
         assert (key != null);
         return index.has(key);
     }
     
-    public synchronized long get(final byte[] key) {
+    public final synchronized long get(final byte[] key) {
         assert (key != null);
         final Row.Entry indexentry = index.get(key);
         if (indexentry == null) return -1;
         return indexentry.getColLong(1);
     }
     
-    public synchronized long put(final byte[] key, final long l) {
+    public final synchronized long put(final byte[] key, final long l) {
         assert l >= 0 : "l = " + l;
         assert (key != null);
         final Row.Entry newentry = index.row().newEntry();
@@ -190,7 +190,7 @@ public class HandleMap implements Iterable<Row.Entry> {
         return oldentry.getColLong(1);
     }
     
-    public synchronized void putUnique(final byte[] key, final long l) {
+    public final synchronized void putUnique(final byte[] key, final long l) {
         assert l >= 0 : "l = " + l;
         assert (key != null);
         final Row.Entry newentry = this.rowdef.newEntry();
@@ -199,7 +199,7 @@ public class HandleMap implements Iterable<Row.Entry> {
         index.addUnique(newentry);
     }
     
-    public synchronized long add(final byte[] key, long a) {
+    public final synchronized long add(final byte[] key, long a) {
         assert key != null;
         assert a > 0; // it does not make sense to add 0. If this occurres, it is a performance issue
 
@@ -217,15 +217,15 @@ public class HandleMap implements Iterable<Row.Entry> {
         return i;
     }
     
-    public synchronized long inc(final byte[] key) {
+    public final synchronized long inc(final byte[] key) {
         return add(key, 1);
     }
     
-    public synchronized long dec(final byte[] key) {
+    public final synchronized long dec(final byte[] key) {
         return add(key, -1);
     }
     
-    public synchronized ArrayList<Long[]> removeDoubles() {
+    public final synchronized ArrayList<Long[]> removeDoubles() {
         final ArrayList<Long[]> report = new ArrayList<Long[]>();
         Long[] is;
         int c;
@@ -244,32 +244,32 @@ public class HandleMap implements Iterable<Row.Entry> {
         return report;
     }
     
-    public synchronized long remove(final byte[] key) {
+    public final synchronized long remove(final byte[] key) {
         assert (key != null);
         final Row.Entry indexentry = index.remove(key);
         if (indexentry == null) return -1;
         return indexentry.getColLong(1);
     }
 
-    public synchronized long removeone() {
+    public final synchronized long removeone() {
         final Row.Entry indexentry = index.removeOne();
         if (indexentry == null) return -1;
         return indexentry.getColLong(1);
     }
     
-    public synchronized int size() {
+    public final synchronized int size() {
         return index.size();
     }
     
-    public synchronized CloneableIterator<byte[]> keys(final boolean up, final byte[] firstKey) {
+    public final synchronized CloneableIterator<byte[]> keys(final boolean up, final byte[] firstKey) {
         return index.keys(up, firstKey);
     }
 
-    public synchronized CloneableIterator<Row.Entry> rows(final boolean up, final byte[] firstKey) {
+    public final synchronized CloneableIterator<Row.Entry> rows(final boolean up, final byte[] firstKey) {
         return index.rows(up, firstKey);
     }
     
-    public synchronized void close() {
+    public final synchronized void close() {
         index.close();
         index = null;
     }
@@ -284,7 +284,7 @@ public class HandleMap implements Iterable<Row.Entry> {
      * @param bufferSize
      * @return
      */
-    public static initDataConsumer asynchronusInitializer(final int keylength, final ByteOrder objectOrder, int idxbytes, final int space, final int expectedspace) {
+    public final static initDataConsumer asynchronusInitializer(final int keylength, final ByteOrder objectOrder, int idxbytes, final int space, final int expectedspace) {
         initDataConsumer initializer = new initDataConsumer(new HandleMap(keylength, objectOrder, idxbytes, space, expectedspace));
         ExecutorService service = Executors.newSingleThreadExecutor();
         initializer.setResult(service.submit(initializer));
@@ -292,7 +292,7 @@ public class HandleMap implements Iterable<Row.Entry> {
         return initializer;
     }
 
-    private static class entry {
+    private final static class entry {
         public byte[] key;
         public long l;
         public entry(final byte[] key, final long l) {
@@ -303,7 +303,7 @@ public class HandleMap implements Iterable<Row.Entry> {
     
     protected static final entry poisonEntry = new entry(new byte[0], 0);
     
-    public static class initDataConsumer implements Callable<HandleMap> {
+    public final static class initDataConsumer implements Callable<HandleMap> {
 
         private BlockingQueue<entry> cache;
         private HandleMap map;
@@ -316,7 +316,7 @@ public class HandleMap implements Iterable<Row.Entry> {
             sortAtEnd = false;
         }
         
-        protected void setResult(Future<HandleMap> result) {
+        protected final void setResult(Future<HandleMap> result) {
             this.result = result;
         }
         
@@ -325,7 +325,7 @@ public class HandleMap implements Iterable<Row.Entry> {
          * @param key
          * @param l
          */
-        public void consume(final byte[] key, final long l) {
+        public final void consume(final byte[] key, final long l) {
             try {
                 cache.put(new entry(key, l));
             } catch (InterruptedException e) {
@@ -337,7 +337,7 @@ public class HandleMap implements Iterable<Row.Entry> {
          * to signal the initialization thread that no more entries will be submitted with consumer()
          * this method must be called. The process will not terminate if this is not called before.
          */
-        public void finish(boolean sortAtEnd) {
+        public final void finish(boolean sortAtEnd) {
             this.sortAtEnd = sortAtEnd;
             try {
                 cache.put(poisonEntry);
@@ -354,11 +354,11 @@ public class HandleMap implements Iterable<Row.Entry> {
          * @throws InterruptedException
          * @throws ExecutionException
          */
-        public HandleMap result() throws InterruptedException, ExecutionException {
+        public final HandleMap result() throws InterruptedException, ExecutionException {
             return this.result.get();
         }
         
-        public HandleMap call() throws IOException {
+        public final HandleMap call() throws IOException {
             try {
                 entry c;
                 while ((c = cache.take()) != poisonEntry) {
diff --git a/source/net/yacy/kelondro/index/HandleSet.java b/source/net/yacy/kelondro/index/HandleSet.java
index 5ad1e5e68..2f4b1d94d 100644
--- a/source/net/yacy/kelondro/index/HandleSet.java
+++ b/source/net/yacy/kelondro/index/HandleSet.java
@@ -38,7 +38,7 @@ import net.yacy.kelondro.order.ByteOrder;
 import net.yacy.kelondro.order.CloneableIterator;
 
 
-public class HandleSet implements Iterable<byte[]> {
+public final class HandleSet implements Iterable<byte[]> {
     
     private final Row rowdef;
     private ObjectIndex index;
@@ -77,7 +77,7 @@ public class HandleSet implements Iterable<byte[]> {
      * @return the number of written entries
      * @throws IOException
      */
-    public int dump(File file) throws IOException {
+    public final int dump(File file) throws IOException {
         // we must use an iterator from the combined index, because we need the entries sorted
         // otherwise we could just write the byte[] from the in kelondroRowSet which would make
         // everything much faster, but this is not an option here.
@@ -93,20 +93,20 @@ public class HandleSet implements Iterable<byte[]> {
         return c;
     }
     
-    public Row row() {
+    public final Row row() {
         return index.row();
     }
     
-    public void clear() throws IOException {
+    public final void clear() throws IOException {
         this.index.clear();
     }
     
-    public synchronized boolean has(final byte[] key) {
+    public final synchronized boolean has(final byte[] key) {
         assert (key != null);
         return index.has(key);
     }
     
-    public synchronized int put(final byte[] key) throws IOException {
+    public final synchronized int put(final byte[] key) throws IOException {
         assert (key != null);
         final Row.Entry newentry = index.row().newEntry();
         newentry.setCol(0, key);
@@ -115,31 +115,31 @@ public class HandleSet implements Iterable<byte[]> {
         return (int) oldentry.getColLong(1);
     }
     
-    public synchronized void putUnique(final byte[] key) throws IOException {
+    public final synchronized void putUnique(final byte[] key) throws IOException {
         assert (key != null);
         final Row.Entry newentry = this.rowdef.newEntry();
         newentry.setCol(0, key);
         index.addUnique(newentry);
     }
     
-    public synchronized int remove(final byte[] key) throws IOException {
+    public final synchronized int remove(final byte[] key) throws IOException {
         assert (key != null);
         final Row.Entry indexentry = index.remove(key);
         if (indexentry == null) return -1;
         return (int) indexentry.getColLong(1);
     }
 
-    public synchronized int removeone() throws IOException {
+    public final synchronized int removeone() throws IOException {
         final Row.Entry indexentry = index.removeOne();
         if (indexentry == null) return -1;
         return (int) indexentry.getColLong(1);
     }
     
-    public synchronized int size() {
+    public final synchronized int size() {
         return index.size();
     }
     
-    public synchronized CloneableIterator<byte[]> keys(final boolean up, final byte[] firstKey) {
+    public final synchronized CloneableIterator<byte[]> keys(final boolean up, final byte[] firstKey) {
         try {
             return index.keys(up, firstKey);
         } catch (IOException e) {
@@ -148,11 +148,11 @@ public class HandleSet implements Iterable<byte[]> {
         }
     }
     
-    public Iterator<byte[]> iterator() {
+    public final Iterator<byte[]> iterator() {
         return keys(true, null);
     }
     
-    public synchronized void close() {
+    public final synchronized void close() {
         index.close();
         index = null;
     }
diff --git a/source/net/yacy/kelondro/index/ObjectArrayCache.java b/source/net/yacy/kelondro/index/ObjectArrayCache.java
index 5bccd6afe..2a00e284c 100644
--- a/source/net/yacy/kelondro/index/ObjectArrayCache.java
+++ b/source/net/yacy/kelondro/index/ObjectArrayCache.java
@@ -32,7 +32,7 @@ import java.util.Random;
 import net.yacy.kelondro.order.NaturalOrder;
 
 
-public class ObjectArrayCache {
+public final class ObjectArrayCache {
 
 	// we use two indexes: one for initialization, and one for data aquired during runtime
 	// this has a gread advantage, if the setup-data is large. Then a re-organisation of
@@ -43,7 +43,7 @@ public class ObjectArrayCache {
 	
     private final Row rowdef;
     private final RowSet index0;
-    private RowSet index1;
+    private       RowSet index1;
     //private final kelondroOrder<kelondroRow.Entry> entryOrder;
     
     public ObjectArrayCache(final int payloadSize, final int initSize) {
@@ -53,17 +53,17 @@ public class ObjectArrayCache {
         //this.entryOrder = new kelondroRow.EntryComparator(rowdef.objectOrder);
     }
     
-    public long memoryNeededForGrow() {
+    public final long memoryNeededForGrow() {
         if (index1 == null) 
             return index0.memoryNeededForGrow();
         return index1.memoryNeededForGrow();
     }
     
-    public Row row() {
+    public final Row row() {
         return index0.row();
     }
     
-    public byte[] getb(final int ii) {
+    public final byte[] getb(final int ii) {
         assert ii >= 0 : "i = " + ii;
     	final byte[] key = NaturalOrder.encodeLong(ii, 4);
         if (index0 != null) {
@@ -82,7 +82,7 @@ public class ObjectArrayCache {
         return indexentry.getColBytes(1);
     }
     
-    public byte[] putb(final int ii, final byte[] value) {
+    public final byte[] putb(final int ii, final byte[] value) {
         assert ii >= 0 : "i = " + ii;
         assert value != null;
         final byte[] key = NaturalOrder.encodeLong(ii, 4);
@@ -114,7 +114,7 @@ public class ObjectArrayCache {
         return oldentry.getColBytes(1);
     }
 
-    public void addb(final int ii, final byte[] value) {
+    public final void addb(final int ii, final byte[] value) {
     	assert index1 == null; // valid only in init-phase
         assert ii >= 0 : "i = " + ii;
         assert value != null;
@@ -124,7 +124,7 @@ public class ObjectArrayCache {
         index0.addUnique(newentry);
     }
     
-    public byte[] removeb(final int ii) {
+    public final byte[] removeb(final int ii) {
         assert ii >= 0 : "i = " + ii;
         
         final byte[] key = NaturalOrder.encodeLong(ii, 4);
@@ -149,7 +149,7 @@ public class ObjectArrayCache {
         return indexentry.getColBytes(1);
     }
     
-    public byte[] removeoneb() {
+    public final byte[] removeoneb() {
         if ((index1 != null) && (index1.size() != 0)) {
             final Row.Entry indexentry = index1.removeOne();
             assert (indexentry != null);
@@ -167,7 +167,7 @@ public class ObjectArrayCache {
         return null;
     }
     
-    public int size() {
+    public final int size() {
         if ((index0 != null) && (index1 == null)) {
             //assert consistencyAnalysis0() : "consistency problem: " + consistencyAnalysis();
             return index0.size();
@@ -181,7 +181,7 @@ public class ObjectArrayCache {
         return index0.size() + index1.size();
     }
     
-    public Iterator<Row.Entry> rows() {
+    public final Iterator<Row.Entry> rows() {
         if (index0 != null) {
             if (index1 == null) {
                 // finish initialization phase
@@ -196,7 +196,7 @@ public class ObjectArrayCache {
         }
     }
     
-    public void flush() {
+    public final void flush() {
         if (index0 != null) {
             index0.sort();
             index0.trim(true);
diff --git a/source/net/yacy/kelondro/index/ObjectIndexCache.java b/source/net/yacy/kelondro/index/ObjectIndexCache.java
index a601373f5..051aaeef5 100644
--- a/source/net/yacy/kelondro/index/ObjectIndexCache.java
+++ b/source/net/yacy/kelondro/index/ObjectIndexCache.java
@@ -34,7 +34,7 @@ import net.yacy.kelondro.order.MergeIterator;
 import net.yacy.kelondro.order.StackIterator;
 
 
-public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
+public final class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
     
     private final Row rowdef;
     private RowSet index0;
@@ -53,13 +53,13 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
 		reset(0);
 	}
     
-	public synchronized void reset(final int initialspace) {
+	public final synchronized void reset(final int initialspace) {
 	    this.index0 = null; // first flush RAM to make room
 	    this.index0 = new RowSet(rowdef, initialspace);
         this.index1 = null; // to show that this is the initialization phase
 	}
     
-    public Row row() {
+    public final Row row() {
         return index0.row();
     }
     
@@ -73,7 +73,7 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
         }
     }
     
-    public synchronized byte[] smallestKey() {
+    public final synchronized byte[] smallestKey() {
         byte[] b0 = index0.smallestKey();
         if (b0 == null) return null;
         if (index1 == null) return b0;
@@ -82,7 +82,7 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
         return b1;
     }
     
-    public synchronized byte[] largestKey() {
+    public final synchronized byte[] largestKey() {
         byte[] b0 = index0.largestKey();
         if (b0 == null) return null;
         if (index1 == null) return b0;
@@ -91,7 +91,7 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
         return b1;
     }
     
-    public synchronized Row.Entry get(final byte[] key) {
+    public final synchronized Row.Entry get(final byte[] key) {
         assert (key != null);
         finishInitialization();
         assert index0.isSorted();
@@ -100,7 +100,7 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
         return index1.get(key);
     }
 
-	public synchronized boolean has(final byte[] key) {
+	public final synchronized boolean has(final byte[] key) {
 		assert (key != null);
         finishInitialization();
         assert index0.isSorted();
@@ -108,7 +108,7 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
         return index1.has(key);
 	}
     
-	public synchronized Row.Entry replace(final Row.Entry entry) {
+	public final synchronized Row.Entry replace(final Row.Entry entry) {
         assert (entry != null);
         finishInitialization();
         // if the new entry is within the initialization part, just overwrite it
@@ -122,7 +122,7 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
         return index1.replace(entry);
     }
    
-	public synchronized void put(final Row.Entry entry) {
+	public final synchronized void put(final Row.Entry entry) {
         assert (entry != null);
         if (entry == null) return;
         finishInitialization();
@@ -137,7 +137,7 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
         index1.put(entry);
     }
    
-    public synchronized void addUnique(final Row.Entry entry) {
+    public final synchronized void addUnique(final Row.Entry entry) {
     	assert (entry != null);
     	if (entry == null) return;
         if (index1 == null) {
@@ -149,12 +149,12 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
         index1.addUnique(entry);
     }
 
-	public void addUnique(final List<Entry> rows) {
+	public final void addUnique(final List<Entry> rows) {
 		final Iterator<Entry> i = rows.iterator();
 		while (i.hasNext()) addUnique(i.next());
 	}
 	
-	public synchronized long inc(final byte[] key, int col, long add, Row.Entry initrow) {
+	public final synchronized long inc(final byte[] key, int col, long add, Row.Entry initrow) {
         assert (key != null);
         finishInitialization();
         assert index0.isSorted();
@@ -163,7 +163,7 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
         return index1.inc(key, col, add, initrow);
     }    
     
-    public synchronized ArrayList<RowCollection> removeDoubles() {
+    public final synchronized ArrayList<RowCollection> removeDoubles() {
 	    // finish initialization phase explicitely
         index0.sort();
 	    if (index1 == null) {
@@ -175,7 +175,7 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
         return d0;
 	}
 	
-    public synchronized Row.Entry remove(final byte[] key) {
+    public final synchronized Row.Entry remove(final byte[] key) {
         finishInitialization();
         // if the new entry is within the initialization part, just delete it
         final Row.Entry indexentry = index0.remove(key);
@@ -189,7 +189,7 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
         return removed;
     }
 
-    public synchronized Row.Entry removeOne() {
+    public final synchronized Row.Entry removeOne() {
         if ((index1 != null) && (index1.size() != 0)) {
             return index1.removeOne();
         }
@@ -199,7 +199,7 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
         return null;
     }
     
-    public synchronized int size() {
+    public final synchronized int size() {
         if ((index0 != null) && (index1 == null)) {
             return index0.size();
         }
@@ -210,7 +210,7 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
         return index0.size() + index1.size();
     }
     
-    public synchronized CloneableIterator<byte[]> keys(final boolean up, final byte[] firstKey) {
+    public final synchronized CloneableIterator<byte[]> keys(final boolean up, final byte[] firstKey) {
         // returns the key-iterator of the underlying kelondroIndex
         if (index1 == null) {
             // finish initialization phase
@@ -239,7 +239,7 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
                 true);
     }
 
-    public synchronized CloneableIterator<Row.Entry> rows(final boolean up, final byte[] firstKey) {
+    public final synchronized CloneableIterator<Row.Entry> rows(final boolean up, final byte[] firstKey) {
         // returns the row-iterator of the underlying kelondroIndex
         if (index1 == null) {
             // finish initialization phase
@@ -269,11 +269,11 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
                 true);
     }
     
-    public Iterator<Entry> iterator() {
+    public final Iterator<Entry> iterator() {
         return rows();
     }
     
-    public synchronized CloneableIterator<Row.Entry> rows() {
+    public final synchronized CloneableIterator<Row.Entry> rows() {
         // returns the row-iterator of the underlying kelondroIndex
         if (index1 == null) {
             // finish initialization phase
@@ -294,16 +294,16 @@ public class ObjectIndexCache implements ObjectIndex, Iterable<Row.Entry> {
         return new StackIterator<Row.Entry>(index0.rows(), index1.rows());
     }
     
-    public synchronized void close() {
+    public final synchronized void close() {
         if (index0 != null) index0.close();
         if (index1 != null) index1.close();
     }
 
-	public String filename() {
+	public final String filename() {
 		return null; // this does not have a file name
 	}
 	
-	public void deleteOnExit() {
+	public final void deleteOnExit() {
         // do nothing, there is no file
     }
 
diff --git a/source/net/yacy/kelondro/index/RowCollection.java b/source/net/yacy/kelondro/index/RowCollection.java
index 9a4de3a55..2eb987117 100644
--- a/source/net/yacy/kelondro/index/RowCollection.java
+++ b/source/net/yacy/kelondro/index/RowCollection.java
@@ -57,12 +57,12 @@ public class RowCollection implements Iterable<Row.Entry> {
     public static final ExecutorService sortingthreadexecutor = (availableCPU > 1) ? Executors.newCachedThreadPool(new NamePrefixThreadFactory("sorting")) : null;
     public static final ExecutorService partitionthreadexecutor = (availableCPU > 1) ? Executors.newCachedThreadPool(new NamePrefixThreadFactory("partition")) : null;
     
-    protected byte[] chunkcache;
-    protected int    chunkcount;
-    protected long   lastTimeWrote;    
-    public Row       rowdef;
-    protected int    sortBound;
-
+    public    final Row    rowdef;
+    protected       byte[] chunkcache;
+    protected       int    chunkcount;
+    protected       int    sortBound;
+    protected       long   lastTimeWrote;
+    
     private static final int exp_chunkcount  = 0;
     private static final int exp_last_read   = 1;
     private static final int exp_last_wrote  = 2;
diff --git a/source/net/yacy/kelondro/index/RowSet.java b/source/net/yacy/kelondro/index/RowSet.java
index e3dd26201..ff15706eb 100644
--- a/source/net/yacy/kelondro/index/RowSet.java
+++ b/source/net/yacy/kelondro/index/RowSet.java
@@ -62,7 +62,7 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
         assert rowdef.objectOrder != null;
     }
     
-    public static RowSet importRowSet(byte[] b, final Row rowdef) {
+    public final static RowSet importRowSet(byte[] b, final Row rowdef) {
     	assert b.length >= exportOverheadSize : "b.length = " + b.length;
     	if (b.length < exportOverheadSize) return new RowSet(rowdef, 0);
         final int size = (int) NaturalOrder.decodeLong(b, 0, 4);
@@ -82,18 +82,18 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
 		super.reset();
 	}
    
-    public synchronized boolean has(final byte[] key) {
+    public final synchronized boolean has(final byte[] key) {
         final int index = find(key, 0, key.length);
         return index >= 0;
     }
     
-    public synchronized Row.Entry get(final byte[] key) {
+    public final synchronized Row.Entry get(final byte[] key) {
         final int index = find(key, 0, key.length);
         if (index < 0) return null;
         return get(index, true);
     }
     
-    public synchronized void put(final Row.Entry entry) {
+    public final synchronized void put(final Row.Entry entry) {
         assert (entry != null);
         assert (entry.getPrimaryKeyBytes() != null);
         // when reaching a specific amount of un-sorted entries, re-sort all
@@ -110,7 +110,7 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
         }
     }
 
-    public synchronized Row.Entry replace(final Row.Entry entry) {
+    public final synchronized Row.Entry replace(final Row.Entry entry) {
         assert (entry != null);
         assert (entry.getPrimaryKeyBytes() != null);
         int index = -1;
@@ -131,7 +131,7 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
         return oldentry;
     }
 
-    public synchronized long inc(byte[] key, int col, long add, Row.Entry initrow) {
+    public final synchronized long inc(byte[] key, int col, long add, Row.Entry initrow) {
         final int index = find(key, 0, key.length);
         if (index >= 0) {
             // the entry existed before
@@ -150,7 +150,7 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
         }
     }
 
-    private Row.Entry remove(final byte[] a, final int start, final int length) {
+    private final Row.Entry remove(final byte[] a, final int start, final int length) {
         final int index = find(a, start, length);
         if (index < 0) {
             return null;
@@ -179,7 +179,7 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
         return entry;
     }
 
-    private int find(final byte[] a, final int astart, final int alength) {
+    private final int find(final byte[] a, final int astart, final int alength) {
         // returns the chunknumber; -1 if not found
         
         if (rowdef.objectOrder == null) return iterativeSearch(a, astart, alength, 0, this.chunkcount);
@@ -206,7 +206,7 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
         }        
     }
     
-    private int iterativeSearch(final byte[] key, final int astart, final int alength, final int leftBorder, final int rightBound) {
+    private final int iterativeSearch(final byte[] key, final int astart, final int alength, final int leftBorder, final int rightBound) {
         // returns the chunknumber        
         for (int i = leftBorder; i < rightBound; i++) {
             if (match(key, astart, alength, i)) return i;
@@ -214,7 +214,7 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
         return -1;
     }
     
-    private int binarySearch(final byte[] key, final int astart, final int alength) {
+    private final int binarySearch(final byte[] key, final int astart, final int alength) {
         // returns the exact position of the key if the key exists,
         // or -1 if the key does not exist
         assert (rowdef.objectOrder != null);
@@ -231,7 +231,7 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
         return -1;
     }
 
-    protected int binaryPosition(final byte[] key, final int astart, final int alength) {
+    protected final int binaryPosition(final byte[] key, final int astart, final int alength) {
         // returns the exact position of the key if the key exists,
         // or a position of an entry that is greater than the key if the
         // key does not exist
@@ -249,16 +249,16 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
         return l;
     }
     
-    public synchronized Iterator<byte[]> keys() {
+    public final synchronized Iterator<byte[]> keys() {
         sort();
         return super.keys(true);
     }
     
-    public synchronized CloneableIterator<byte[]> keys(final boolean up, final byte[] firstKey) {
+    public final synchronized CloneableIterator<byte[]> keys(final boolean up, final byte[] firstKey) {
         return new keyIterator(up, firstKey);
     }
     
-    public class keyIterator implements CloneableIterator<byte[]> {
+    public final class keyIterator implements CloneableIterator<byte[]> {
 
         private final boolean up;
         private final byte[] first;
@@ -279,11 +279,11 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
             }
         }
         
-		public keyIterator clone(final Object second) {
+		public final keyIterator clone(final Object second) {
             return new keyIterator(up, (byte[]) second);
         }
         
-        public boolean hasNext() {
+        public final boolean hasNext() {
         	if (p < 0) return false;
         	if (p >= size()) return false;
             if (up) {
@@ -293,32 +293,32 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
             }
         }
 
-        public byte[] next() {
+        public final byte[] next() {
             final byte[] key = getKey(p);
             if (up) p++; else p--;
             return key;
         }
         
-        public void remove() {
+        public final void remove() {
             throw new UnsupportedOperationException();
         }
     }
     
-    public synchronized Iterator<Row.Entry> iterator() {
+    public final synchronized Iterator<Row.Entry> iterator() {
         // iterates kelondroRow.Entry - type entries
         sort();
         return super.iterator();
     }
     
-    public synchronized CloneableIterator<Row.Entry> rows(final boolean up, final byte[] firstKey) {
+    public final synchronized CloneableIterator<Row.Entry> rows(final boolean up, final byte[] firstKey) {
         return new rowIterator(up, firstKey);
     }
     
-    public synchronized CloneableIterator<Row.Entry> rows() {
+    public final synchronized CloneableIterator<Row.Entry> rows() {
         return new rowIterator(true, null);
     }
     
-    public class rowIterator implements CloneableIterator<Row.Entry> {
+    public final class rowIterator implements CloneableIterator<Row.Entry> {
 
         private final boolean up;
         private final byte[] first;
@@ -339,11 +339,11 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
             }
         }
         
-		public rowIterator clone(final Object second) {
+		public final rowIterator clone(final Object second) {
             return new rowIterator(up, (byte[]) second);
         }
         
-        public boolean hasNext() {
+        public final boolean hasNext() {
         	if (p < 0) return false;
         	if (p >= size()) return false;
             if (up) {
@@ -353,13 +353,13 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
             }
         }
 
-        public Row.Entry next() {
+        public final Row.Entry next() {
             final Row.Entry entry = get(p, true);
             if (up) p++; else p--;
             return entry;
         }
         
-        public void remove() {
+        public final void remove() {
             throw new UnsupportedOperationException();
         }
     }
@@ -372,7 +372,7 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
      * @param c
      * @return
      */
-    public RowSet merge(RowSet c) {
+    public final RowSet merge(RowSet c) {
         assert c != null;
         /*
         if (this.isSorted() && this.size() >= c.size()) {
@@ -400,7 +400,7 @@ public class RowSet extends RowCollection implements ObjectIndex, Iterable<Row.E
      * @param c
      * @return
      */
-    protected static RowSet mergeEnum(RowCollection c0, RowCollection c1) {
+    protected final static RowSet mergeEnum(RowCollection c0, RowCollection c1) {
         assert c0.rowdef == c1.rowdef : c0.rowdef.toString() + " != " + c1.rowdef.toString();
         RowSet r = new RowSet(c0.rowdef, c0.size() + c1.size());
         try {
diff --git a/source/net/yacy/kelondro/index/RowSetArray.java b/source/net/yacy/kelondro/index/RowSetArray.java
index 785ddf04e..8c9a4a2d7 100644
--- a/source/net/yacy/kelondro/index/RowSetArray.java
+++ b/source/net/yacy/kelondro/index/RowSetArray.java
@@ -32,7 +32,7 @@ import net.yacy.kelondro.order.MergeIterator;
 import net.yacy.kelondro.order.StackIterator;
 
 
-public class RowSetArray implements ObjectIndex, Iterable<Row.Entry> {
+public final class RowSetArray implements ObjectIndex, Iterable<Row.Entry> {
 
     private final int      objectCount;
     private final Row      rowdef;
@@ -47,15 +47,15 @@ public class RowSetArray implements ObjectIndex, Iterable<Row.Entry> {
         this.objectCount = objectCount / arraySize;
     }
     
-    private int indexFor(byte[] key) {
+    private final int indexFor(byte[] key) {
         return (int) (this.rowdef.objectOrder.cardinal(key) % ((long) array.length));
     }
     
-    private int indexFor(Entry row) {
+    private final int indexFor(Entry row) {
         return (int) (this.rowdef.objectOrder.cardinal(row.bytes(), 0, row.getPrimaryKeyLength()) % ((long) array.length));
     }
     
-    private RowSet accessArray(int i) {
+    private final RowSet accessArray(int i) {
         RowSet r = this.array[i];
         if (r == null) synchronized (this.array) {
             r = new RowSet(this.rowdef, this.objectCount);
@@ -64,17 +64,17 @@ public class RowSetArray implements ObjectIndex, Iterable<Row.Entry> {
         return r;
     }
     
-    public void addUnique(Entry row) {
+    public final void addUnique(Entry row) {
         int i = indexFor(row);
         if (i < 0) return;
         accessArray(i).addUnique(row);
     }
 
-    public void addUnique(List<Entry> rows) {
+    public final void addUnique(List<Entry> rows) {
         for (Entry row: rows) addUnique(row);
     }
 
-    public void clear() {
+    public final void clear() {
         synchronized (this.array) {
             for (int i = 0; i < this.array.length; i++) {
                 if (this.array[i] != null) this.array[i].clear();
@@ -83,20 +83,20 @@ public class RowSetArray implements ObjectIndex, Iterable<Row.Entry> {
         }
     }
 
-    public void close() {
+    public final void close() {
         clear();
     }
 
-    public void deleteOnExit() {
+    public final void deleteOnExit() {
         // no nothing here
     }
 
-    public String filename() {
+    public final String filename() {
         // we don't have a file name
         return null;
     }
 
-    public Entry get(byte[] key) {
+    public final Entry get(byte[] key) {
         int i = indexFor(key);
         if (i < 0) return null;
         RowSet r = this.array[i];
@@ -104,7 +104,7 @@ public class RowSetArray implements ObjectIndex, Iterable<Row.Entry> {
         return r.get(key);
     }
 
-    public boolean has(byte[] key) {
+    public final boolean has(byte[] key) {
         int i = indexFor(key);
         if (i < 0) return false;
         RowSet r = this.array[i];
@@ -112,7 +112,7 @@ public class RowSetArray implements ObjectIndex, Iterable<Row.Entry> {
         return r.has(key);
     }
 
-    public CloneableIterator<byte[]> keys(boolean up, byte[] firstKey) {
+    public final CloneableIterator<byte[]> keys(boolean up, byte[] firstKey) {
         synchronized (this.array) {
             Collection<CloneableIterator<byte[]>> col = new ArrayList<CloneableIterator<byte[]>>();
             for (int i = 0; i < this.array.length; i++) {
@@ -125,19 +125,19 @@ public class RowSetArray implements ObjectIndex, Iterable<Row.Entry> {
         }            
     }
 
-    public void put(Entry row) {
+    public final void put(Entry row) {
         int i = indexFor(row);
         if (i < 0) return;
         accessArray(i).put(row);
     }
 
-    public Entry remove(byte[] key) {
+    public final Entry remove(byte[] key) {
         int i = indexFor(key);
         if (i < 0) return null;
         return accessArray(i).remove(key);
     }
 
-    public ArrayList<RowCollection> removeDoubles() {
+    public final ArrayList<RowCollection> removeDoubles() {
         ArrayList<RowCollection> col = new ArrayList<RowCollection>();
         synchronized (this.array) {
             for (int i = 0; i < this.array.length; i++) {
@@ -150,7 +150,7 @@ public class RowSetArray implements ObjectIndex, Iterable<Row.Entry> {
         return col;
     }
 
-    public Entry removeOne() {
+    public final Entry removeOne() {
         synchronized (this.array) {
             for (int i = 0; i < this.array.length; i++) {
                 if (this.array[i] != null) {
@@ -163,17 +163,17 @@ public class RowSetArray implements ObjectIndex, Iterable<Row.Entry> {
         return null;
     }
 
-    public Entry replace(Entry row) {
+    public final Entry replace(Entry row) {
         int i = indexFor(row);
         if (i < 0) return null;
         return accessArray(i).replace(row);
     }
 
-    public Row row() {
+    public final Row row() {
         return this.rowdef;
     }
 
-    public CloneableIterator<Entry> rows(boolean up, byte[] firstKey) {
+    public final CloneableIterator<Entry> rows(boolean up, byte[] firstKey) {
         synchronized (this.array) {
             Collection<CloneableIterator<Entry>> col = new ArrayList<CloneableIterator<Entry>>();
             for (int i = 0; i < this.array.length; i++) {
@@ -186,11 +186,11 @@ public class RowSetArray implements ObjectIndex, Iterable<Row.Entry> {
         }
     }
 
-    public CloneableIterator<Entry> rows() {
+    public final CloneableIterator<Entry> rows() {
         return rows(true, null);
     }
 
-    public int size() {
+    public final int size() {
         int c = 0;
         synchronized (this.array) {
             for (int i = 0; i < this.array.length; i++) {
@@ -202,11 +202,11 @@ public class RowSetArray implements ObjectIndex, Iterable<Row.Entry> {
         return c;
     }
 
-    public Iterator<Entry> iterator() {
+    public final Iterator<Entry> iterator() {
         return this.rows(true, null);
     }
 
-    public long inc(byte[] key, int col, long add, Entry initrow) {
+    public final long inc(byte[] key, int col, long add, Entry initrow) {
         int i = indexFor(key);
         if (i < 0) return -1;
         return accessArray(i).inc(key, col, add, initrow);
diff --git a/source/net/yacy/kelondro/index/SimpleARC.java b/source/net/yacy/kelondro/index/SimpleARC.java
index ddccec17b..f3a76bce4 100644
--- a/source/net/yacy/kelondro/index/SimpleARC.java
+++ b/source/net/yacy/kelondro/index/SimpleARC.java
@@ -37,14 +37,14 @@ import java.util.Map;
  * at the same size.
  */
 
-public class SimpleARC<K, V> implements ARC<K, V> {
+public final class SimpleARC<K, V> implements ARC<K, V> {
 
     public    final static boolean accessOrder = false; // if false, then a insertion-order is used
     
-    protected int cacheSize;
-    private   Map<K, V> levelA, levelB;
+    protected final int cacheSize;
+    private   final Map<K, V> levelA, levelB;
     
-    public SimpleARC(int cacheSize) {
+    public SimpleARC(final int cacheSize) {
         this.cacheSize = cacheSize / 2;
         this.levelA = new LinkedHashMap<K, V>(cacheSize, 0.1f, accessOrder) {
             private static final long serialVersionUID = 1L;
@@ -65,7 +65,7 @@ public class SimpleARC<K, V> implements ARC<K, V> {
      * @param s
      * @param v
      */
-    public synchronized void put(K s, V v) {
+    public final synchronized void put(K s, V v) {
         if (this.levelB.containsKey(s)) {
         	this.levelB.put(s, v);
             assert (this.levelB.size() <= cacheSize); // the cache should shrink automatically
@@ -80,7 +80,7 @@ public class SimpleARC<K, V> implements ARC<K, V> {
      * @param s
      * @return the value
      */
-    public synchronized V get(K s) {
+    public final synchronized V get(K s) {
         V v = this.levelB.get(s);
         if (v != null) return v;
         v = this.levelA.remove(s);
@@ -97,7 +97,7 @@ public class SimpleARC<K, V> implements ARC<K, V> {
      * @param s
      * @return
      */
-    public synchronized boolean containsKey(K s) {
+    public final synchronized boolean containsKey(K s) {
         if (this.levelB.containsKey(s)) return true;
         return this.levelA.containsKey(s);
     }
@@ -107,7 +107,7 @@ public class SimpleARC<K, V> implements ARC<K, V> {
      * @param s
      * @return the old value
      */
-    public synchronized V remove(K s) {
+    public final synchronized V remove(K s) {
         V r = this.levelB.remove(s);
         if (r != null) return r;
         return this.levelA.remove(s);
@@ -116,7 +116,7 @@ public class SimpleARC<K, V> implements ARC<K, V> {
     /**
      * clear the cache
      */
-    public synchronized void clear() {
+    public final synchronized void clear() {
         this.levelA.clear();
         this.levelB.clear();
     }