From db1eae0227d3ce20e4bd91d420062dd392e0a1d3 Mon Sep 17 00:00:00 2001
From: orbiter <orbiter@6c8d7289-2bf4-0310-a012-ef5d649a1542>
Date: Thu, 24 Aug 2006 02:19:25 +0000
Subject: [PATCH] * simplified initialization of database objects * replaced
 kelondroTree for NURLs by kelondroFlex * replaced kelondroTree for EURLs by
 kelondroFlex take care, may be very buggy please finish crawls before
 updating. crawls will be lost.

git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@2452 6c8d7289-2bf4-0310-a012-ef5d649a1542
---
 doc/News.html                                 |  5 +-
 source/dbtest.java                            | 13 +--
 source/de/anomic/data/blogBoard.java          |  8 +-
 source/de/anomic/data/bookmarksDB.java        | 72 +++-----------
 source/de/anomic/data/messageBoard.java       |  9 +-
 source/de/anomic/data/userDB.java             | 20 +---
 source/de/anomic/data/wikiBoard.java          | 20 +---
 .../de/anomic/index/indexContainerOrder.java  |  4 +
 source/de/anomic/index/indexRAMCacheRI.java   |  4 +-
 source/de/anomic/index/indexURL.java          |  2 +-
 .../kelondro/kelondroAbstractOrder.java       |  8 ++
 .../kelondro/kelondroCollectionIndex.java     | 13 +--
 source/de/anomic/kelondro/kelondroDyn.java    | 53 ++++++-----
 .../de/anomic/kelondro/kelondroDynTree.java   | 35 +------
 .../kelondro/kelondroFixedWidthArray.java     | 36 +++----
 .../de/anomic/kelondro/kelondroFlexTable.java | 14 +--
 .../kelondro/kelondroFlexWidthArray.java      | 10 +-
 .../de/anomic/kelondro/kelondroHashtable.java | 37 +++-----
 .../de/anomic/kelondro/kelondroMapTable.java  | 34 ++-----
 source/de/anomic/kelondro/kelondroOrder.java  |  2 +
 .../de/anomic/kelondro/kelondroRecords.java   | 43 ++++-----
 .../anomic/kelondro/kelondroSplittedTree.java | 49 ++--------
 source/de/anomic/kelondro/kelondroStack.java  | 60 ++++++------
 source/de/anomic/kelondro/kelondroTree.java   | 91 +++++++++++-------
 .../de/anomic/plasma/plasmaCrawlBalancer.java | 10 +-
 source/de/anomic/plasma/plasmaCrawlEURL.java  | 27 ++++--
 source/de/anomic/plasma/plasmaCrawlLURL.java  | 22 ++---
 source/de/anomic/plasma/plasmaCrawlNURL.java  | 67 ++++++-------
 .../de/anomic/plasma/plasmaCrawlProfile.java  | 15 +--
 .../anomic/plasma/plasmaCrawlRobotsTxt.java   | 18 +---
 .../de/anomic/plasma/plasmaCrawlStacker.java  | 93 ++++++++++---------
 source/de/anomic/plasma/plasmaHTCache.java    |  5 +-
 .../anomic/plasma/plasmaRankingCRProcess.java |  2 +-
 .../anomic/plasma/plasmaSwitchboardQueue.java | 10 +-
 source/de/anomic/plasma/plasmaURLPool.java    |  4 +-
 .../anomic/plasma/plasmaWordConnotation.java  | 10 +-
 .../plasma/plasmaWordIndexAssortment.java     | 29 ++----
 .../de/anomic/plasma/plasmaWordIndexFile.java | 24 ++---
 source/de/anomic/yacy/yacyNewsDB.java         | 16 +---
 source/de/anomic/yacy/yacyNewsQueue.java      | 26 +-----
 source/de/anomic/yacy/yacySeedDB.java         | 17 +---
 source/yacy.java                              |  2 +-
 42 files changed, 395 insertions(+), 644 deletions(-)

diff --git a/doc/News.html b/doc/News.html
index dc0d685ab..56d301495 100644
--- a/doc/News.html
+++ b/doc/News.html
@@ -84,7 +84,7 @@ globalheader();
 </ul>
 -->
 
-<br>v0.46_20060823_2442<p>
+<br><p>v0.46_20060823_2442
 <ul>
 <li>Web Interface Enhancements</li>
   <ul>
@@ -130,7 +130,8 @@ globalheader();
   </ul>
 </ul>
 
-<br><p>v0.45_20060501_2046<ul>
+<br><p>v0.45_20060501_2046
+<ul>
 <li>Enhanced Search Functions</li>
   <ul>
   <li>Re-designed search page: this shows now a simplified page without the left navigation column. The column is only shown if the user is logged-in.</li>
diff --git a/source/dbtest.java b/source/dbtest.java
index d40fed422..e11178027 100644
--- a/source/dbtest.java
+++ b/source/dbtest.java
@@ -173,23 +173,18 @@ public class dbtest {
             kelondroRow testRow = new kelondroRow("byte[] key-" + keylength + ", byte[] dummy-" + keylength + ", value-" + valuelength);
             if (dbe.equals("kelondroTree")) {
                 File tablefile = new File(tablename + ".kelondro.db");
-                if (tablefile.exists()) {
-                    table = new kelondroTree(tablefile, buffer, preload, kelondroTree.defaultObjectCachePercent);
-                } else {
-                    table = new kelondroTree(tablefile, buffer, preload, kelondroTree.defaultObjectCachePercent, testRow, true);
-                }
+                table = new kelondroTree(tablefile, buffer, preload, kelondroTree.defaultObjectCachePercent, testRow);
             }
             if (dbe.equals("kelondroSplittedTree")) {
                 File tablepath = new File(tablename).getParentFile();
                 tablename = new File(tablename).getName();
-                table = kelondroSplittedTree.open(tablepath, tablename, kelondroBase64Order.enhancedCoder,
+                table = new kelondroSplittedTree(tablepath, tablename, kelondroBase64Order.enhancedCoder,
                                 buffer, preload,
-                                8, testRow, 1, 80,
-                                true);
+                                8, testRow, 1, 80);
             }
             if (dbe.equals("kelondroFlexTable")) {
                 File tablepath = new File(tablename).getParentFile();
-                table = new kelondroFlexTable(tablepath, new File(tablename).getName(), kelondroBase64Order.enhancedCoder, buffer, preload, testRow, true);
+                table = new kelondroFlexTable(tablepath, new File(tablename).getName(), kelondroBase64Order.enhancedCoder, buffer, preload, testRow);
             }
             if (dbe.equals("mysql")) {
                 table = new dbTable("mysql", testRow);
diff --git a/source/de/anomic/data/blogBoard.java b/source/de/anomic/data/blogBoard.java
index ee1619617..0a7489842 100644
--- a/source/de/anomic/data/blogBoard.java
+++ b/source/de/anomic/data/blogBoard.java
@@ -83,13 +83,7 @@ public class blogBoard {
     public blogBoard(File actpath, int bufferkb, long preloadTime) {
     		new File(actpath.getParent()).mkdir();
         if (datbase == null) {
-            if (actpath.exists()) try {
-                datbase = new kelondroMap(new kelondroDyn(actpath, bufferkb / 2 * 0x40, preloadTime, '_'));
-            } catch (IOException e) {
-                datbase = new kelondroMap(new kelondroDyn(actpath, bufferkb / 2 * 0x400, preloadTime, keyLength, recordSize, '_', true));
-            } else {
-                datbase = new kelondroMap(new kelondroDyn(actpath, bufferkb / 2 * 0x400, preloadTime, keyLength, recordSize, '_', true));
-            }
+            datbase = new kelondroMap(kelondroDyn.open(actpath, bufferkb / 2 * 0x40, preloadTime, keyLength, recordSize, '_'));
         }
     }
     
diff --git a/source/de/anomic/data/bookmarksDB.java b/source/de/anomic/data/bookmarksDB.java
index 0cfd4aea2..98eba79db 100644
--- a/source/de/anomic/data/bookmarksDB.java
+++ b/source/de/anomic/data/bookmarksDB.java
@@ -120,67 +120,25 @@ public class bookmarksDB {
     }
     
     public bookmarksDB(File bookmarksFile, File tagsFile, File datesFile, int bufferkb, long preloadTime) {
-        //bookmarks
-        //check if database exists
+        // bookmarks
         tagCache=new HashMap();
         bookmarkCache=new HashMap();
-        if(bookmarksFile.exists()){
-            try {
-                //open it
-                this.bookmarksTable=new kelondroMap(new kelondroDyn(bookmarksFile, 1024*bufferkb, preloadTime, '_'));
-            } catch (IOException e) {
-                //database reset :-((
-                bookmarksFile.delete();
-                bookmarksFile.getParentFile().mkdirs();
-                //urlHash is 12 bytes long
-                this.bookmarksTable = new kelondroMap(new kelondroDyn(bookmarksFile, bufferkb * 1024, preloadTime, 12, 256, '_', true));
-            }
-        }else{
-            //new database
-            bookmarksFile.getParentFile().mkdirs();
-            this.bookmarksTable = new kelondroMap(new kelondroDyn(bookmarksFile, bufferkb * 1024, preloadTime, 12, 256, '_', true));
-        }
-        //tags
-        //check if database exists
-        if(tagsFile.exists()){
-            try {
-                //open it
-                this.tagsTable=new kelondroMap(new kelondroDyn(tagsFile, 1024*bufferkb, preloadTime, '_'));
-            } catch (IOException e) {
-                //reset database
-                tagsFile.delete();
-                tagsFile.getParentFile().mkdirs();
-                // max. 128 byte long tags
-                this.tagsTable = new kelondroMap(new kelondroDyn(tagsFile, bufferkb * 1024, preloadTime, 12, 256, '_', true));
-                rebuildTags();
-            }
-        }else{
-            //new database
-            tagsFile.getParentFile().mkdirs();
-            this.tagsTable = new kelondroMap(new kelondroDyn(tagsFile, bufferkb * 1024, preloadTime, 12, 256, '_', true));
-            rebuildTags();
-        }
+        bookmarksFile.getParentFile().mkdirs();
+        this.bookmarksTable = new kelondroMap(kelondroDyn.open(bookmarksFile, bufferkb * 1024, preloadTime, 12, 256, '_'));
+
+        // tags
+        tagsFile.getParentFile().mkdirs();
+        boolean tagsFileExisted = tagsFile.exists();
+        this.tagsTable = new kelondroMap(kelondroDyn.open(tagsFile, bufferkb * 1024, preloadTime, 12, 256, '_'));
+        if (!tagsFileExisted) rebuildTags();
+
         // dates
-        //check if database exists
-        if(datesFile.exists()){
-            try {
-                //open it
-                this.datesTable=new kelondroMap(new kelondroDyn(datesFile, 1024*bufferkb, preloadTime, '_'));
-            } catch (IOException e) {
-                //reset database
-                datesFile.delete();
-                datesFile.getParentFile().mkdirs();
-                //YYYY-MM-DDTHH:mm:ssZ = 20 byte. currently used: YYYY-MM-DD = 10 bytes
-                this.datesTable = new kelondroMap(new kelondroDyn(datesFile, bufferkb * 1024, preloadTime, 20, 256, '_', true));
-                rebuildDates();
-            }
-        }else{
-            //new database
-            datesFile.getParentFile().mkdirs();
-            this.datesTable = new kelondroMap(new kelondroDyn(datesFile, bufferkb * 1024, preloadTime, 20, 256, '_', true));
-            rebuildDates();
-        }
+        boolean datesExisted = datesFile.exists();
+        this.datesTable = new kelondroMap(kelondroDyn.open(datesFile, bufferkb * 1024, preloadTime, 20, 256, '_'));
+        if (!datesExisted) rebuildDates();
+        
     }
+    
     public void close(){
         try {
             flushBookmarkCache();
diff --git a/source/de/anomic/data/messageBoard.java b/source/de/anomic/data/messageBoard.java
index aff347614..41c8b17c7 100644
--- a/source/de/anomic/data/messageBoard.java
+++ b/source/de/anomic/data/messageBoard.java
@@ -70,14 +70,7 @@ public class messageBoard {
     public messageBoard(File path, int bufferkb, long preloadTime) {
         new File(path.getParent()).mkdir();
         if (database == null) {
-            if (path.exists()) try {
-                database = new kelondroMap(new kelondroDyn(path, bufferkb * 0x400, preloadTime, '_'));
-            } catch (IOException e) {
-                path.delete();
-                database = new kelondroMap(new kelondroDyn(path, bufferkb * 0x400, preloadTime, categoryLength + dateFormat.length() + 2, recordSize, '_', true));
-            } else {
-                database = new kelondroMap(new kelondroDyn(path, bufferkb * 0x400, preloadTime, categoryLength + dateFormat.length() + 2, recordSize, '_', true));
-            }
+            database = new kelondroMap(kelondroDyn.open(path, bufferkb * 0x400, preloadTime, categoryLength + dateFormat.length() + 2, recordSize, '_'));
         }
         sn = 0;
     }
diff --git a/source/de/anomic/data/userDB.java b/source/de/anomic/data/userDB.java
index 2a1ce1055..a155af52c 100644
--- a/source/de/anomic/data/userDB.java
+++ b/source/de/anomic/data/userDB.java
@@ -76,22 +76,8 @@ public final class userDB {
         this.userTableFile = userTableFile;
         this.bufferkb = bufferkb;
         this.preloadTime = preloadTime;
-        if (userTableFile.exists()) {
-            try {
-                this.userTable = new kelondroMap(new kelondroDyn(userTableFile, bufferkb * 1024, preloadTime, '_'));
-            } catch (kelondroException e) {
-                userTableFile.delete();
-                userTableFile.getParentFile().mkdirs();
-                this.userTable = new kelondroMap(new kelondroDyn(userTableFile, bufferkb * 1024, preloadTime, 128, 256, '_', true));
-            } catch (IOException e) {
-                userTableFile.delete();
-                userTableFile.getParentFile().mkdirs();
-                this.userTable = new kelondroMap(new kelondroDyn(userTableFile, bufferkb * 1024, preloadTime, 128, 256, '_', true));
-            }
-        } else {
-            userTableFile.getParentFile().mkdirs();
-            this.userTable = new kelondroMap(new kelondroDyn(userTableFile, bufferkb * 1024, preloadTime, 128, 256, '_', true));
-        }
+        userTableFile.getParentFile().mkdirs();
+        this.userTable = new kelondroMap(kelondroDyn.open(userTableFile, bufferkb * 1024, preloadTime, 128, 256, '_'));
     }
     
     public int dbCacheNodeChunkSize() {
@@ -109,7 +95,7 @@ public final class userDB {
         } catch (IOException e) {}
         if (!(userTableFile.delete())) throw new RuntimeException("cannot delete user database");
         userTableFile.getParentFile().mkdirs();
-        userTable = new kelondroMap(new kelondroDyn(userTableFile, this.bufferkb, preloadTime, 256, 512, '_', true));
+        userTable = new kelondroMap(kelondroDyn.open(userTableFile, this.bufferkb, preloadTime, 256, 512, '_'));
     }
     
     public void close() {
diff --git a/source/de/anomic/data/wikiBoard.java b/source/de/anomic/data/wikiBoard.java
index b5353f190..2e00a4ce1 100644
--- a/source/de/anomic/data/wikiBoard.java
+++ b/source/de/anomic/data/wikiBoard.java
@@ -70,25 +70,13 @@ public class wikiBoard {
     private static HashMap authors = new HashMap();
     
     public wikiBoard(File actpath, File bkppath, int bufferkb, long preloadTime) {
-    		new File(actpath.getParent()).mkdir();
+    		new File(actpath.getParent()).mkdirs();
         if (datbase == null) {
-            if (actpath.exists()) try {
-                datbase = new kelondroMap(new kelondroDyn(actpath, bufferkb / 2 * 0x40, preloadTime, '_'));
-            } catch (IOException e) {
-                datbase = new kelondroMap(new kelondroDyn(actpath, bufferkb / 2 * 0x400, preloadTime, keyLength, recordSize, '_', true));
-            } else {
-                datbase = new kelondroMap(new kelondroDyn(actpath, bufferkb / 2 * 0x400, preloadTime, keyLength, recordSize, '_', true));
-            }
+            datbase = new kelondroMap(kelondroDyn.open(actpath, bufferkb / 2 * 0x400, preloadTime, keyLength, recordSize, '_'));
         }
-        new File(bkppath.getParent()).mkdir();
+        new File(bkppath.getParent()).mkdirs();
         if (bkpbase == null) {
-            if (bkppath.exists()) try {
-                bkpbase = new kelondroMap(new kelondroDyn(bkppath, bufferkb / 2 * 0x400, preloadTime, '_'));
-            } catch (IOException e) {
-                bkpbase = new kelondroMap(new kelondroDyn(bkppath, bufferkb / 2 * 0x400, preloadTime, keyLength + dateFormat.length(), recordSize, '_', true));
-            } else {
-                bkpbase = new kelondroMap(new kelondroDyn(bkppath, bufferkb / 2 * 0x400, preloadTime, keyLength + dateFormat.length(), recordSize, '_', true));
-            }
+            bkpbase = new kelondroMap(kelondroDyn.open(bkppath, bufferkb / 2 * 0x400, preloadTime, keyLength + dateFormat.length(), recordSize, '_'));
         }
     }
 
diff --git a/source/de/anomic/index/indexContainerOrder.java b/source/de/anomic/index/indexContainerOrder.java
index 7bc3d8ca4..e39872a60 100644
--- a/source/de/anomic/index/indexContainerOrder.java
+++ b/source/de/anomic/index/indexContainerOrder.java
@@ -53,4 +53,8 @@ public class indexContainerOrder implements kelondroOrder {
         return this.embeddedOrder.compare(a, aoffset, alength, b, boffset, blength);
     }
 
+    public boolean equals(kelondroOrder otherOrder) {
+        if (!(otherOrder instanceof indexContainerOrder)) return false;
+        return this.embeddedOrder.equals(((indexContainerOrder) otherOrder).embeddedOrder);
+    }
 }
diff --git a/source/de/anomic/index/indexRAMCacheRI.java b/source/de/anomic/index/indexRAMCacheRI.java
index 063ffca0a..770337259 100644
--- a/source/de/anomic/index/indexRAMCacheRI.java
+++ b/source/de/anomic/index/indexRAMCacheRI.java
@@ -96,7 +96,7 @@ public final class indexRAMCacheRI extends indexAbstractRI implements indexRI {
         File indexDumpFile = new File(databaseRoot, indexArrayFileName);
         if (indexDumpFile.exists()) indexDumpFile.delete();
         kelondroFixedWidthArray dumpArray = null;
-            dumpArray = new kelondroFixedWidthArray(indexDumpFile, plasmaWordIndexAssortment.bufferStructureBasis, 0, false);
+            dumpArray = new kelondroFixedWidthArray(indexDumpFile, plasmaWordIndexAssortment.bufferStructureBasis, 0);
             long startTime = System.currentTimeMillis();
             long messageTime = System.currentTimeMillis() + 5000;
             long wordsPerSecond = 0, wordcount = 0, urlcount = 0;
@@ -175,7 +175,7 @@ public final class indexRAMCacheRI extends indexAbstractRI implements indexRI {
     private long restore() throws IOException {
         File indexDumpFile = new File(databaseRoot, indexArrayFileName);
         if (!(indexDumpFile.exists())) return 0;
-        kelondroFixedWidthArray dumpArray = new kelondroFixedWidthArray(indexDumpFile, plasmaWordIndexAssortment.bufferStructureBasis);
+        kelondroFixedWidthArray dumpArray = new kelondroFixedWidthArray(indexDumpFile, plasmaWordIndexAssortment.bufferStructureBasis, 0);
         log.logConfig("restore array dump of index cache, " + dumpArray.size() + " word/URL relations");
         long startTime = System.currentTimeMillis();
         long messageTime = System.currentTimeMillis() + 5000;
diff --git a/source/de/anomic/index/indexURL.java b/source/de/anomic/index/indexURL.java
index 9eed64942..7d2eb4823 100644
--- a/source/de/anomic/index/indexURL.java
+++ b/source/de/anomic/index/indexURL.java
@@ -451,7 +451,7 @@ public class indexURL {
  
  public long[] cacheObjectStatus() {
      if (urlHashCache instanceof kelondroTree) return ((kelondroTree) urlHashCache).cacheObjectStatus();
-     return null;
+     return new long[]{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
  }
  
  public static final int flagTypeID(String hash) {
diff --git a/source/de/anomic/kelondro/kelondroAbstractOrder.java b/source/de/anomic/kelondro/kelondroAbstractOrder.java
index 059068ecf..2dc6f03eb 100644
--- a/source/de/anomic/kelondro/kelondroAbstractOrder.java
+++ b/source/de/anomic/kelondro/kelondroAbstractOrder.java
@@ -83,4 +83,12 @@ public abstract class kelondroAbstractOrder implements kelondroOrder {
     public void rotate(byte[] newzero) {
         this.zero = newzero;
     }
+    
+    public boolean equals(kelondroOrder otherOrder) {
+        String thisSig = this.signature();
+        String otherSig = otherOrder.signature();
+        if ((thisSig == null) || (otherSig == null)) return false;
+        return thisSig.equals(otherSig);
+    }
+    
 }
diff --git a/source/de/anomic/kelondro/kelondroCollectionIndex.java b/source/de/anomic/kelondro/kelondroCollectionIndex.java
index 16c63b32c..1976d6aa2 100644
--- a/source/de/anomic/kelondro/kelondroCollectionIndex.java
+++ b/source/de/anomic/kelondro/kelondroCollectionIndex.java
@@ -91,7 +91,7 @@ public class kelondroCollectionIndex {
         this.loadfactor = loadfactor;
 
         // create index table
-        index = new kelondroFlexTable(path, filenameStub + ".index.table", indexOrder, buffersize, preloadTime, indexRow(keyLength), true);
+        index = new kelondroFlexTable(path, filenameStub + ".index.table", indexOrder, buffersize, preloadTime, indexRow(keyLength));
 
         // save/check property file for this array
         File propfile = propertyFile(path, filenameStub, loadfactor, rowdef.objectsize());
@@ -119,13 +119,8 @@ public class kelondroCollectionIndex {
                 "byte[] key-" + index.row().width(0) + "," +
                 "byte[] collection-" + (kelondroRowCollection.exportOverheadSize + load * this.playloadrow.objectsize())
                 );
-        if (f.exists()) {
-            return new kelondroFixedWidthArray(f, rowdef);
-        } else if (create) {
-            return new kelondroFixedWidthArray(f, rowdef, 0, true);
-        } else {
-            return null;
-        }
+        if ((!(f.exists())) && (!create)) return null;
+        return new kelondroFixedWidthArray(f, rowdef, 0);
     }
     
     private kelondroFixedWidthArray getArray(int partitionNumber, int serialNumber, int chunksize) {
@@ -460,7 +455,7 @@ public class kelondroCollectionIndex {
             collectionIndex.close();
             
             // printout of index
-            kelondroFlexTable index = new kelondroFlexTable(path, filenameStub + ".index", kelondroNaturalOrder.naturalOrder, buffersize, preloadTime, indexRow(9), true);
+            kelondroFlexTable index = new kelondroFlexTable(path, filenameStub + ".index", kelondroNaturalOrder.naturalOrder, buffersize, preloadTime, indexRow(9));
             index.print();
             index.close();
         } catch (IOException e) {
diff --git a/source/de/anomic/kelondro/kelondroDyn.java b/source/de/anomic/kelondro/kelondroDyn.java
index df7ff9c84..54faf4a8d 100644
--- a/source/de/anomic/kelondro/kelondroDyn.java
+++ b/source/de/anomic/kelondro/kelondroDyn.java
@@ -68,31 +68,43 @@ public class kelondroDyn extends kelondroTree {
     private char fillChar;
     private kelondroObjectBuffer buffer;
     
-    public kelondroDyn(File file, long buffersize /*bytes*/, long preloadTime, int key, int nodesize, char fillChar, boolean exitOnFail) {
-        this(file, buffersize, preloadTime, key, nodesize, fillChar, new kelondroNaturalOrder(true), exitOnFail);
+    public kelondroDyn(File file, long buffersize /*bytes*/, long preloadTime, int key, int nodesize, char fillChar) throws IOException {
+        this(file, buffersize, preloadTime, key, nodesize, fillChar, new kelondroNaturalOrder(true));
     }
     
     public kelondroDyn(File file, long buffersize /* bytes */, long preloadTime, int key,
-            int nodesize, char fillChar, kelondroOrder objectOrder,
-            boolean exitOnFail) {
-        // creates a new dynamic tree
-        super(file, buffersize, preloadTime,  kelondroTree.defaultObjectCachePercent, new kelondroRow("byte[] key-" + (key + counterlen) + ", byte[] node-" + nodesize), objectOrder, 1, 8, exitOnFail);
+            int nodesize, char fillChar, kelondroOrder objectOrder) throws IOException {
+        // creates or opens a dynamic tree
+        super(file, buffersize, preloadTime,  kelondroTree.defaultObjectCachePercent, new kelondroRow("byte[] key-" + (key + counterlen) + ", byte[] node-" + nodesize), objectOrder, 1, 8);
         this.keylen = row().width(0) - counterlen;
         this.reclen = row().width(1);
         this.fillChar = fillChar;
         this.segmentCount = 0;
-        writeSegmentCount();
+        if (!(super.fileExisted)) writeSegmentCount();
         buffer = new kelondroObjectBuffer(file.toString());
     }
-
-    public kelondroDyn(File file, long buffersize, long preloadTime, char fillChar) throws IOException {
-        // this opens a file with an existing dynamic tree
-        super(file, buffersize, preloadTime, kelondroTree.defaultObjectCachePercent);
-        this.keylen = row().width(0) - counterlen;
-        this.reclen = row().width(1);
-        this.fillChar = fillChar;
-        this.segmentCount = 0;
-        buffer = new kelondroObjectBuffer(file.toString());
+    
+    public static final kelondroDyn open(File file, long buffersize /* bytes */, long preloadTime, int key, int nodesize, char fillChar) {
+        return open(file, buffersize, preloadTime, key, nodesize, fillChar, new kelondroNaturalOrder(true));
+    }
+    
+    public static final kelondroDyn open(File file, long buffersize /* bytes */, long preloadTime, int key,
+            int nodesize, char fillChar, kelondroOrder objectOrder) {
+        // opens new or existing file; in case that any error occur the file is deleted again and it is tried to create the file again
+        // if that fails, the method returns null
+        try {
+            return new kelondroDyn(file, buffersize, preloadTime, key, nodesize, fillChar, objectOrder);
+        } catch (IOException e) {
+            file.delete();
+            try {
+                return new kelondroDyn(file, buffersize, preloadTime, key, nodesize, fillChar, objectOrder);
+            } catch (IOException ee) {
+                log.severe("cannot open or create file " + file.toString());
+                e.printStackTrace();
+                ee.printStackTrace();
+                return null;
+            }
+        }
     }
     
     private void writeSegmentCount() {
@@ -442,7 +454,7 @@ public class kelondroDyn extends kelondroTree {
         } else if (args.length == 1) {
             // open a db and list keys
             try {
-                kelondroDyn kd = new kelondroDyn(new File(args[0]), 0x100000, 0, '_');
+                kelondroDyn kd = new kelondroDyn(new File(args[0]), 0x100000, 0, 4 ,100, '_');
                 System.out.println(kd.size() + " elements in DB");
                 Iterator i = kd.dynKeys(true, false);
                 while (i.hasNext())
@@ -459,10 +471,7 @@ public class kelondroDyn extends kelondroTree {
             File f = new File(args[3]);
             kelondroDyn kd;
             try {
-                if (db.exists())
-                    kd = new kelondroDyn(db, 0x100000, 0, '_');
-                else
-                    kd = new kelondroDyn(db, 0x100000, 0, 80, 200, '_', true);
+                kd = new kelondroDyn(db, 0x100000, 0, 80, 200, '_');
                 if (writeFile)
                     kd.readFile(key, f);
                 else
@@ -486,7 +495,7 @@ public class kelondroDyn extends kelondroTree {
             int steps = 0;
             while (true) {
                 if (testFile.exists()) testFile.delete();
-                tt = new kelondroDyn(testFile, 0, 0, 4 ,100, '_', true);
+                tt = new kelondroDyn(testFile, 0, 0, 4 ,100, '_');
                 steps = ((int) System.currentTimeMillis() % 7) * (((int) System.currentTimeMillis() + 17) % 11);
                 t = s;
                 d = "";
diff --git a/source/de/anomic/kelondro/kelondroDynTree.java b/source/de/anomic/kelondro/kelondroDynTree.java
index c64c4d278..8b10e5b76 100644
--- a/source/de/anomic/kelondro/kelondroDynTree.java
+++ b/source/de/anomic/kelondro/kelondroDynTree.java
@@ -48,7 +48,6 @@ import java.io.File;
 import java.io.IOException;
 import java.util.Enumeration;
 import java.util.Hashtable;
-import java.util.Iterator;
 
 public class kelondroDynTree {
     
@@ -70,8 +69,8 @@ public class kelondroDynTree {
     private Hashtable buffer, cache;
     private long cycleBuffer;
     
-    public kelondroDynTree(File file, long buffersize, long preloadTime, int keylength, int nodesize, kelondroRow rowdef, char fillChar, boolean exitOnFail) {
-        // creates a new DynTree
+    public kelondroDynTree(File file, long buffersize, long preloadTime, int keylength, int nodesize, kelondroRow rowdef, char fillChar) throws IOException {
+        // creates or opens a DynTree
         this.file = file;
         this.buffersize = buffersize;
         this.preloadTime = preloadTime;
@@ -80,33 +79,9 @@ public class kelondroDynTree {
         this.cache = new Hashtable();
         //this.cycleCache = Long.MIN_VALUE;
         this.cycleBuffer = Long.MIN_VALUE;
-        if (file.exists()) file.delete();
-        this.table = new kelondroDyn(file, buffersize, preloadTime, keylength, nodesize, fillChar, exitOnFail);
+        this.table = new kelondroDyn(file, buffersize, preloadTime, keylength, nodesize, fillChar);
         this.treeRAHandles = new Hashtable();
     }
-
-    public kelondroDynTree(File file, long buffersize, long preloadTime, char fillChar) throws IOException {
-        // opens an existing DynTree
-        this.file = file;
-        this.buffersize = buffersize;
-        this.preloadTime = preloadTime;
-        this.buffer = new Hashtable();
-        this.cache = new Hashtable();
-        //this.cycleCache = Long.MIN_VALUE;
-        this.cycleBuffer = Long.MIN_VALUE;
-        if (!(file.exists())) throw new IOException("DynTree " + file.toString() + " does not exist");
-        this.table = new kelondroDyn(file, buffersize, preloadTime, fillChar);
-        // read one element to measure the size of columns
-        if (table.size() == 0) throw new IOException("DynTree " + file.toString() + " is empty. Should not.");
-        this.treeRAHandles = new Hashtable();
-        Iterator i = table.dynKeys(true, false);
-        String onekey = (String) i.next();
-        kelondroTree onetree = getTree(onekey);
-        kelondroColumn[] columns = new kelondroColumn[onetree.row().columns()];
-        for (int j = 0; j < columns.length; j++) columns[j] = onetree.row().column(j);
-        this.rowdef = new kelondroRow(columns);
-        closeTree(onekey);
-    }
     
     public void close() throws IOException {
         Enumeration e = treeRAHandles.keys();
@@ -323,10 +298,10 @@ public class kelondroDynTree {
             System.out.println("start");
             File file = new File("D:\\bin\\testDyn.db");
             if (file.exists()) {
-                kelondroDynTree dt = new kelondroDynTree(file, 0x100000L, 0, '_');
+                kelondroDynTree dt = new kelondroDynTree(file, 0x100000L, 0, 16, 512, new kelondroRow("byte[] a-10, byte[] b-20, byte[] c-30"), '_');
                 System.out.println("opened: table keylength=" + dt.table.row().width(0) + ", sectorsize=" + dt.table.row().width(1) + ", " + dt.table.size() + " entries.");
             } else {
-                kelondroDynTree dt = new kelondroDynTree(file, 0x100000L, 0, 16, 512, new kelondroRow("byte[] a-10, byte[] b-20, byte[] c-30"), '_', true);
+                kelondroDynTree dt = new kelondroDynTree(file, 0x100000L, 0, 16, 512, new kelondroRow("byte[] a-10, byte[] b-20, byte[] c-30"), '_');
                 String name;
                 kelondroTree t;
                 kelondroRow.Entry line;
diff --git a/source/de/anomic/kelondro/kelondroFixedWidthArray.java b/source/de/anomic/kelondro/kelondroFixedWidthArray.java
index a0bf160e7..d8b0c8df4 100644
--- a/source/de/anomic/kelondro/kelondroFixedWidthArray.java
+++ b/source/de/anomic/kelondro/kelondroFixedWidthArray.java
@@ -55,27 +55,19 @@ public class kelondroFixedWidthArray extends kelondroRecords implements kelondro
     private static short thisOHBytes   = 0; // our record definition does not need extra bytes
     private static short thisOHHandles = 0; // and no handles
     
-    public kelondroFixedWidthArray(File file, kelondroRow rowdef, int intprops, boolean exitOnFail) {
+    public kelondroFixedWidthArray(File file, kelondroRow rowdef, int intprops) throws IOException {
         // this creates a new array
-        super(file, 0, 0, thisOHBytes, thisOHHandles, rowdef, intprops, rowdef.columns() /* txtProps */, 80 /* txtPropWidth */, exitOnFail);
-        for (int i = 0; i < intprops; i++) try {
-            setHandle(i, new Handle(0));
-        } catch (IOException e) {
-            super.logFailure("cannot set handle " + i + " / " + e.getMessage());
-            if (exitOnFail) System.exit(-1);
-            throw new RuntimeException("cannot set handle " + i + " / " + e.getMessage());
-        }
-        // store column description
-        for (int i = 0; i < rowdef.columns(); i++) {
-            try {super.setText(i, rowdef.column(i).toString().getBytes());} catch (IOException e) {}
+        super(file, 0, 0, thisOHBytes, thisOHHandles, rowdef, intprops, rowdef.columns() /* txtProps */, 80 /* txtPropWidth */);
+        if (!(super.fileExisted)) {
+            for (int i = 0; i < intprops; i++) {
+                setHandle(i, new Handle(0));
+            }
+            // store column description
+            for (int i = 0; i < rowdef.columns(); i++) {
+                try {super.setText(i, rowdef.column(i).toString().getBytes());} catch (IOException e) {}
+            }
         }
     }
-
-    public kelondroFixedWidthArray(File file, kelondroRow rowdef) throws IOException{
-        // this opens a file with an existing array
-        super(file, 0, 0);
-        super.assignRowdef(rowdef);
-    }
     
     public synchronized kelondroRow.Entry set(int index, kelondroRow.Entry rowentry) throws IOException {
 
@@ -142,14 +134,14 @@ public class kelondroFixedWidthArray extends kelondroRecords implements kelondro
         try {
             System.out.println("erster Test");
             f.delete();
-            kelondroFixedWidthArray k = new kelondroFixedWidthArray(f, rowdef, 6, true);
+            kelondroFixedWidthArray k = new kelondroFixedWidthArray(f, rowdef, 6);
             k.set(3, k.row().newEntry(new byte[][]{
                 "test123".getBytes(), "abcd".getBytes()}));
             k.add(k.row().newEntry(new byte[][]{
                 "test456".getBytes(), "efgh".getBytes()}));
             k.close();
             
-            k = new kelondroFixedWidthArray(f, rowdef);
+            k = new kelondroFixedWidthArray(f, rowdef, 6);
             System.out.println(k.get(2).toString());
             System.out.println(k.get(3).toString());
             System.out.println(k.get(4).toString());
@@ -157,7 +149,7 @@ public class kelondroFixedWidthArray extends kelondroRecords implements kelondro
 
             System.out.println("zweiter Test");
             f.delete();
-            k = new kelondroFixedWidthArray(f, rowdef, 6, true);
+            k = new kelondroFixedWidthArray(f, rowdef, 6);
             k.add(k.row().newEntry(new byte[][]{"a".getBytes(), "xxxx".getBytes()}));
             k.add(k.row().newEntry(new byte[][]{"b".getBytes(), "xxxx".getBytes()}));
             k.remove(0);
@@ -176,7 +168,7 @@ public class kelondroFixedWidthArray extends kelondroRecords implements kelondro
             
             System.out.println("dritter Test");
             f.delete();
-            k = new kelondroFixedWidthArray(f, rowdef, 6, true);
+            k = new kelondroFixedWidthArray(f, rowdef, 6);
             for (int i = 1; i <= 200; i = i * 2) {
                 for (int j = 0; j < i*2; j++) {
                     k.add(k.row().newEntry(new byte[][]{(Integer.toString(i) + "-" + Integer.toString(j)).getBytes(), "xxxx".getBytes()}));
diff --git a/source/de/anomic/kelondro/kelondroFlexTable.java b/source/de/anomic/kelondro/kelondroFlexTable.java
index 78748ec1a..d935b8eaa 100644
--- a/source/de/anomic/kelondro/kelondroFlexTable.java
+++ b/source/de/anomic/kelondro/kelondroFlexTable.java
@@ -33,8 +33,8 @@ public class kelondroFlexTable extends kelondroFlexWidthArray implements kelondr
 
     protected kelondroBytesIntMap index;
     
-    public kelondroFlexTable(File path, String tablename, kelondroOrder objectOrder, long buffersize, long preloadTime, kelondroRow rowdef, boolean exitOnFail) throws IOException {
-        super(path, tablename, rowdef, exitOnFail);
+    public kelondroFlexTable(File path, String tablename, kelondroOrder objectOrder, long buffersize, long preloadTime, kelondroRow rowdef) throws IOException {
+        super(path, tablename, rowdef);
         File newpath = new File(path, tablename);
         File indexfile = new File(newpath, "col.000.index");
         kelondroIndex ki = null;
@@ -52,7 +52,7 @@ public class kelondroFlexTable extends kelondroFlexWidthArray implements kelondr
         if (indexfile.exists()) {
             // use existing index file
             System.out.println("*** Using File index " + indexfile);
-            ki = new kelondroTree(indexfile, buffersize, preloadTime, 10);
+            ki = kelondroTree.open(indexfile, buffersize, preloadTime, 10, treeIndexRow(rowdef.width(0)), objectOrder, 2, 80);
         } else if ((preloadTime >= 0) && (stt > preloadTime)) {
             // generate new index file
             System.out.print("*** Generating File index for " + size() + " entries from " + indexfile);
@@ -104,9 +104,7 @@ public class kelondroFlexTable extends kelondroFlexWidthArray implements kelondr
     }
     
     private kelondroTree initializeTreeIndex(File indexfile, long buffersize, long preloadTime, kelondroOrder objectOrder) throws IOException {
-        kelondroTree treeindex = new kelondroTree(indexfile, buffersize, preloadTime, 10,
-                new kelondroRow("byte[] key-" + rowdef.width(0) + ", int reference-4 {b256}"),
-                objectOrder, 2, 80, true);
+        kelondroTree treeindex = new kelondroTree(indexfile, buffersize, preloadTime, 10, treeIndexRow(rowdef.width(0)), objectOrder, 2, 80);
         Iterator content = super.col[0].contentNodes(-1);
         kelondroRecords.Node node;
         kelondroRow.Entry indexentry;
@@ -126,6 +124,10 @@ public class kelondroFlexTable extends kelondroFlexWidthArray implements kelondr
         return treeindex;
     }
     
+    private static final kelondroRow treeIndexRow(int keywidth) {
+        return new kelondroRow("byte[] key-" + keywidth + ", int reference-4 {b256}");
+    }
+    
     public synchronized kelondroRow.Entry get(byte[] key) throws IOException {
         synchronized (index) {
             int i = index.geti(key);
diff --git a/source/de/anomic/kelondro/kelondroFlexWidthArray.java b/source/de/anomic/kelondro/kelondroFlexWidthArray.java
index e2eb1990f..3047ff00b 100644
--- a/source/de/anomic/kelondro/kelondroFlexWidthArray.java
+++ b/source/de/anomic/kelondro/kelondroFlexWidthArray.java
@@ -37,7 +37,7 @@ public class kelondroFlexWidthArray implements kelondroArray {
     protected kelondroFixedWidthArray[] col;
     protected kelondroRow rowdef;
     
-    public kelondroFlexWidthArray(File path, String tablename, kelondroRow rowdef, boolean exitOnFail) throws IOException {
+    public kelondroFlexWidthArray(File path, String tablename, kelondroRow rowdef) throws IOException {
         this.rowdef = rowdef;
         
         // initialize columns
@@ -81,7 +81,7 @@ public class kelondroFlexWidthArray implements kelondroArray {
                 
                 kelondroColumn columns[] = new kelondroColumn[colend - colstart + 1];
                 for (int j = colstart; j <= colend; j++) columns[j-colstart] = rowdef.column(j);
-                col[colstart] = new kelondroFixedWidthArray(new File(tabledir, files[i]), new kelondroRow(columns));
+                col[colstart] = new kelondroFixedWidthArray(new File(tabledir, files[i]), new kelondroRow(columns), 16);
                 for (int j = colstart; j <= colend; j++) check = check.substring(0, j) + "X" + check.substring(j + 1);
             }
         }
@@ -100,7 +100,7 @@ public class kelondroFlexWidthArray implements kelondroArray {
                 columns[j - p] = rowdef.column(j);
                 check = check.substring(0, j) + "X" + check.substring(j + 1);
             }
-            col[p] = new kelondroFixedWidthArray(new File(tabledir, colfilename(p, q)), new kelondroRow(columns), 16, true);
+            col[p] = new kelondroFixedWidthArray(new File(tabledir, colfilename(p, q)), new kelondroRow(columns), 16);
         }
     }
     
@@ -224,7 +224,7 @@ public class kelondroFlexWidthArray implements kelondroArray {
             System.out.println("erster Test");
             new File(f, testname).delete();
             
-            kelondroFlexWidthArray k = new kelondroFlexWidthArray(f, "flextest", rowdef, true);
+            kelondroFlexWidthArray k = new kelondroFlexWidthArray(f, "flextest", rowdef);
             k.add(k.row().newEntry(new byte[][]{"a".getBytes(), "xxxx".getBytes()}));
             k.add(k.row().newEntry(new byte[][]{"b".getBytes(), "xxxx".getBytes()}));
             k.remove(0);
@@ -244,7 +244,7 @@ public class kelondroFlexWidthArray implements kelondroArray {
             
             System.out.println("zweiter Test");
             new File(f, testname).delete();
-            k = new kelondroFlexWidthArray(f, "flextest", rowdef, true);
+            k = new kelondroFlexWidthArray(f, "flextest", rowdef);
             for (int i = 1; i <= 20; i = i * 2) {
                 for (int j = 0; j < i*2; j++) {
                     k.add(k.row().newEntry(new byte[][]{(Integer.toString(i) + "-" + Integer.toString(j)).getBytes(), "xxxx".getBytes()}));
diff --git a/source/de/anomic/kelondro/kelondroHashtable.java b/source/de/anomic/kelondro/kelondroHashtable.java
index 65b02bbbe..f93e9cad0 100644
--- a/source/de/anomic/kelondro/kelondroHashtable.java
+++ b/source/de/anomic/kelondro/kelondroHashtable.java
@@ -142,7 +142,7 @@ public class kelondroHashtable {
     
     private   static final byte[] dummyKey = kelondroBase64Order.enhancedCoder.encodeLong(0, 5).getBytes();
 
-    public kelondroHashtable(File file, kelondroRow rowdef, int offset, int maxsize, int maxrehash, boolean exitOnFail) {
+    public kelondroHashtable(File file, kelondroRow rowdef, int offset, int maxsize, int maxrehash) throws IOException {
         // this creates a new hashtable
         // the key element is not part of the columns array
         // this is unlike the kelondroTree, where the key is part of a row
@@ -152,32 +152,25 @@ public class kelondroHashtable {
         // this number is needed to omit grow of the table in case of re-hashing
         // the maxsize is re-computed to a virtual folding height and will result in a tablesize
         // less than the given maxsize. The actual maxsize can be retrieved by maxsize()
-        this.hashArray = new kelondroFixedWidthArray(file, extCol(rowdef), 6, exitOnFail);
-        this.offset = offset;
-        this.maxk = kelondroMSetTools.log2a(maxsize); // equal to |log2(maxsize)| + 1
-        if (this.maxk >= kelondroMSetTools.log2a(maxsize + power2(offset + 1) + 1) - 1) this.maxk--;
-        this.maxrehash = maxrehash;
-        dummyRow = this.hashArray.row().newEntry();
-        dummyRow.setCol(0, dummyKey);
-        for (int i = 0; i < hashArray.row().columns(); i++)
-        try {
+        boolean fileExisted = file.exists();
+        this.hashArray = new kelondroFixedWidthArray(file, extCol(rowdef), 6);
+        if (fileExisted) {
+            this.offset    = hashArray.geti(0);
+            this.maxk      = hashArray.geti(1);
+            this.maxrehash = hashArray.geti(2);
+        } else {
+            this.offset = offset;
+            this.maxk = kelondroMSetTools.log2a(maxsize); // equal to |log2(maxsize)| + 1
+            if (this.maxk >= kelondroMSetTools.log2a(maxsize + power2(offset + 1) + 1) - 1) this.maxk--;
+            this.maxrehash = maxrehash;
+            dummyRow = this.hashArray.row().newEntry();
+            dummyRow.setCol(0, dummyKey);
+            //for (int i = 0; i < hashArray.row().columns(); i++)
             hashArray.seti(0, this.offset);
             hashArray.seti(1, this.maxk);
             hashArray.seti(2, this.maxrehash);
-        } catch (IOException e) {
-            hashArray.logFailure("cannot set properties / " + e.getMessage());
-            if (exitOnFail) System.exit(-1);
-            throw new RuntimeException("cannot set properties / " + e.getMessage());
         }
     }
-
-    public kelondroHashtable(File file, kelondroRow rowdef) throws IOException{
-        // this opens a file with an existing hashtable
-        this.hashArray = new kelondroFixedWidthArray(file, rowdef);
-        this.offset    = hashArray.geti(0);
-        this.maxk      = hashArray.geti(1);
-        this.maxrehash = hashArray.geti(2);
-    }
     
     private kelondroRow extCol(kelondroRow rowdef) {
         kelondroColumn[] newCol = new kelondroColumn[rowdef.columns() + 1];
diff --git a/source/de/anomic/kelondro/kelondroMapTable.java b/source/de/anomic/kelondro/kelondroMapTable.java
index 3e0127f3f..9f32bacac 100644
--- a/source/de/anomic/kelondro/kelondroMapTable.java
+++ b/source/de/anomic/kelondro/kelondroMapTable.java
@@ -63,51 +63,35 @@ public class kelondroMapTable {
     
     public void declareMaps(
             String tablename, int keysize, int nodesize,
-            char fillChar, boolean exitOnFail) {
-        declareMaps(tablename, keysize, nodesize, null, null, fillChar, exitOnFail);
+            char fillChar) throws IOException {
+        declareMaps(tablename, keysize, nodesize, null, null, fillChar);
     }
     
     public void declareMaps(
             String tablename, int keysize, int nodesize,
-            String[] sortfields, String[] accfields, char fillChar, boolean exitOnFail) {
-        declareMaps(tablename, keysize, nodesize, sortfields, accfields, fillChar, 0x800, 0, exitOnFail);
+            String[] sortfields, String[] accfields, char fillChar) throws IOException {
+        declareMaps(tablename, keysize, nodesize, sortfields, accfields, fillChar, 0x800, 0);
     }
     
     public void declareMaps(
             String tablename, int keysize, int nodesize,
             String[] sortfields, String[] accfields, char fillChar,
-            long buffersize /*bytes*/, long preloadTime, boolean exitOnFail) {
+            long buffersize /*bytes*/, long preloadTime) throws IOException {
         if (mTables.containsKey(tablename)) throw new RuntimeException("kelondroTables.declareMap: table '" + tablename + "' declared twice.");
         if (tTables.containsKey(tablename)) throw new RuntimeException("kelondroTables.declareMap: table '" + tablename + "' declared already in other context.");
         File tablefile = new File(tablesPath, "table." + tablename + ".mdb");
         kelondroDyn dyn;
-        if (tablefile.exists()) try {
-            dyn = new kelondroDyn(tablefile, buffersize, preloadTime, fillChar);
-        } catch (IOException e) {
-            tablefile.getParentFile().mkdirs();
-            dyn = new kelondroDyn(tablefile, buffersize, preloadTime, keysize, nodesize, fillChar, exitOnFail);
-        } else {
-            tablefile.getParentFile().mkdirs();
-            dyn = new kelondroDyn(tablefile, buffersize, preloadTime, keysize, nodesize, fillChar, exitOnFail);
-        }
+        if (!(tablefile.exists())) tablefile.getParentFile().mkdirs();
+        dyn = new kelondroDyn(tablefile, buffersize, preloadTime, keysize, nodesize, fillChar);
         kelondroMap map = new kelondroMap(dyn, sortfields, accfields);
         mTables.put(tablename, map);
     }
     
-    public void declareTree(String tablename, kelondroRow rowdef, long buffersize /*bytes*/, long preloadTime, boolean exitOnFail)  {
+    public void declareTree(String tablename, kelondroRow rowdef, long buffersize /*bytes*/, long preloadTime)  {
         if (mTables.containsKey(tablename)) throw new RuntimeException("kelondroTables.declareTree: table '" + tablename + "' declared already in other context.");
         if (tTables.containsKey(tablename)) throw new RuntimeException("kelondroTables.declareTree: table '" + tablename + "' declared twice.");
         File tablefile = new File(tablesPath, "table." + tablename + ".tdb");
-        kelondroTree Tree;
-        if (tablefile.exists()) try {
-            Tree = new kelondroTree(tablefile, buffersize, preloadTime, kelondroTree.defaultObjectCachePercent);
-        } catch (IOException e) {
-            tablefile.getParentFile().mkdirs();
-            Tree = new kelondroTree(tablefile, buffersize, preloadTime, kelondroTree.defaultObjectCachePercent, rowdef, exitOnFail);
-        } else {
-            tablefile.getParentFile().mkdirs();
-            Tree = new kelondroTree(tablefile, buffersize, preloadTime, kelondroTree.defaultObjectCachePercent, rowdef, exitOnFail);
-        }
+        kelondroTree Tree = kelondroTree.open(tablefile, buffersize, preloadTime, kelondroTree.defaultObjectCachePercent, rowdef);
         tTables.put(tablename, Tree);
     }
 
diff --git a/source/de/anomic/kelondro/kelondroOrder.java b/source/de/anomic/kelondro/kelondroOrder.java
index e7aa90682..4fa0c1f10 100644
--- a/source/de/anomic/kelondro/kelondroOrder.java
+++ b/source/de/anomic/kelondro/kelondroOrder.java
@@ -66,4 +66,6 @@ public interface kelondroOrder extends Comparator {
     public byte[] zero(); // returns the zero point of the Ordering; null if not defined
 
     public void rotate(byte[] zero); // defines that the ordering rotates, and sets the zero point for the rotation
+    
+    public boolean equals(kelondroOrder o); // used to compare different order objects; they may define the same ordering
 }
diff --git a/source/de/anomic/kelondro/kelondroRecords.java b/source/de/anomic/kelondro/kelondroRecords.java
index bc93a5981..ff2595370 100644
--- a/source/de/anomic/kelondro/kelondroRecords.java
+++ b/source/de/anomic/kelondro/kelondroRecords.java
@@ -150,6 +150,9 @@ public class kelondroRecords {
     // optional logger
     protected Logger theLogger = null;
     
+    // tracking of file cration
+    protected boolean fileExisted;
+    
     // Random. This is used to shift flush-times of write-buffers to differrent time
     private static Random random = new Random(System.currentTimeMillis());
 
@@ -191,30 +194,34 @@ public class kelondroRecords {
     
     public kelondroRecords(File file, long buffersize /* bytes */, long preloadTime,
                            short ohbytec, short ohhandlec,
-                           kelondroRow rowdef, int FHandles, int txtProps, int txtPropWidth,
-                           boolean exitOnFail) {
-        // creates a new file
+                           kelondroRow rowdef, int FHandles, int txtProps, int txtPropWidth) throws IOException {
+        // opens an existing file or creates a new file
         // file: the file that shall be created
         // oha : overhead size array of four bytes: oha[0]=# of bytes, oha[1]=# of shorts, oha[2]=# of ints, oha[3]=# of longs, 
         // columns: array with size of column width; columns.length is number of columns
         // FHandles: number of integer properties
         // txtProps: number of text properties
 
-        assert (!file.exists()) : "file " + file + " already exist";
-        try {
+        this.fileExisted = file.exists(); // can be used by extending class to track if this class created the file
+        if (file.exists()) {
+            // opens an existing tree
+            this.filename = file.getCanonicalPath();
+            kelondroRA raf = new kelondroFileRA(this.filename);
+            //kelondroRA raf = new kelondroBufferedRA(new kelondroFileRA(this.filename), 1024, 100);
+            //kelondroRA raf = new kelondroCachedRA(new kelondroFileRA(this.filename), 5000000, 1000);
+            //kelondroRA raf = new kelondroNIOFileRA(this.filename, (file.length() < 4000000), 10000);
+            initExistingFile(raf, buffersize / 10);
+        } else {
             this.filename = file.getCanonicalPath();
             kelondroRA raf = new kelondroFileRA(this.filename);
             // kelondroRA raf = new kelondroBufferedRA(new kelondroFileRA(this.filename), 1024, 100);
             // kelondroRA raf = new kelondroNIOFileRA(this.filename, false, 10000);
             initNewFile(raf, ohbytec, ohhandlec, rowdef, FHandles, txtProps, txtPropWidth, buffersize / 10);
-        } catch (IOException e) {
-            logFailure("cannot create / " + e.getMessage());
-            if (exitOnFail)
-                System.exit(-1);
         }
-        initCache(buffersize / 10 * 9, preloadTime);
+        assignRowdef(rowdef);
+        initCache(buffersize / 10 * 9, preloadTime);        
     }
-    
+
     public kelondroRecords(kelondroRA ra, long buffersize /* bytes */, long preloadTime,
                            short ohbytec, short ohhandlec,
                            kelondroRow rowdef, int FHandles, int txtProps, int txtPropWidth,
@@ -347,18 +354,6 @@ public class kelondroRecords {
         this.USAGE.write();
     }
 
-    public kelondroRecords(File file, long buffersize, long preloadTime) throws IOException{
-        // opens an existing tree
-        assert (file.exists()): "file " + file.getAbsoluteFile().toString() + " does not exist";
-        this.filename = file.getCanonicalPath();
-        kelondroRA raf = new kelondroFileRA(this.filename);
-        //kelondroRA raf = new kelondroBufferedRA(new kelondroFileRA(this.filename), 1024, 100);
-        //kelondroRA raf = new kelondroCachedRA(new kelondroFileRA(this.filename), 5000000, 1000);
-        //kelondroRA raf = new kelondroNIOFileRA(this.filename, (file.length() < 4000000), 10000);
-        initExistingFile(raf, buffersize / 10);
-        initCache(buffersize / 10 * 9, preloadTime);
-    }
-    
     public kelondroRecords(kelondroRA ra, long buffersize, long preloadTime) throws IOException{
         this.filename = null;
         initExistingFile(ra, buffersize / 10);
@@ -912,7 +907,7 @@ public class kelondroRecords {
         return this.ROW;
     }
     
-    public final void assignRowdef(kelondroRow rowdef) {
+    private final void assignRowdef(kelondroRow rowdef) {
         // overwrites a given rowdef
         // the new rowdef must be compatible
         if (rowdef.columns() < ROW.columns())
diff --git a/source/de/anomic/kelondro/kelondroSplittedTree.java b/source/de/anomic/kelondro/kelondroSplittedTree.java
index 8dcf7764e..11f7be948 100644
--- a/source/de/anomic/kelondro/kelondroSplittedTree.java
+++ b/source/de/anomic/kelondro/kelondroSplittedTree.java
@@ -65,64 +65,27 @@ public class kelondroSplittedTree implements kelondroIndex {
         return new File(path, filenameStub + "." + ff + "." + co + "." + ns + ".ktc");
     }
 
+    /*
     private static boolean existsAll(File pathToFiles, String filenameStub, int forkfactor, int columns){
         for (int i = 0; i < forkfactor; i++) {
             if (!(dbFile(pathToFiles, filenameStub, forkfactor, columns, i)).exists()) return false;
         }
         return true;
     }
+    */
     
     public kelondroSplittedTree(File pathToFiles, String filenameStub, kelondroOrder objectOrder,
                             long buffersize, long preloadTime,
-                            int forkfactor, kelondroRow rowdef, int txtProps, int txtPropsWidth,
-                            boolean exitOnFail) {
+                            int forkfactor, kelondroRow rowdef, int txtProps, int txtPropsWidth) {
         ktfs = new kelondroTree[forkfactor];
         File f;
         for (int i = 0; i < forkfactor; i++) {
             f = dbFile(pathToFiles, filenameStub, forkfactor, rowdef.columns(), i);
-            if (f.exists()) {
-                try {
-                    ktfs[i] = new kelondroTree(f, buffersize/forkfactor, preloadTime / forkfactor, kelondroTree.defaultObjectCachePercent);
-                    this.order = ktfs[i].order();
-                } catch (IOException e) {
-                    ktfs[i] = new kelondroTree(f, buffersize/forkfactor, preloadTime / forkfactor, kelondroTree.defaultObjectCachePercent,
-                            rowdef, objectOrder, txtProps, txtPropsWidth, exitOnFail);
-                    this.order = objectOrder;
-                }
-            } else {
-                ktfs[i] = new kelondroTree(f, buffersize/forkfactor, preloadTime / forkfactor, kelondroTree.defaultObjectCachePercent,
-                        rowdef, objectOrder, txtProps, txtPropsWidth, exitOnFail);
-                this.order = objectOrder;
-            }
+            ktfs[i] = kelondroTree.open(f, buffersize/forkfactor, preloadTime / forkfactor, kelondroTree.defaultObjectCachePercent,
+                        rowdef, objectOrder, txtProps, txtPropsWidth);
         }
-        ff = forkfactor;
-    }
-
-    public kelondroSplittedTree(File pathToFiles, String filenameStub, kelondroOrder objectOrder,
-                            long buffersize, long preloadTime, int forkfactor, int columns) throws IOException {
-        ktfs = new kelondroTree[forkfactor];
-        for (int i = 0; i < forkfactor; i++) {
-            ktfs[i] = new kelondroTree(dbFile(pathToFiles, filenameStub, forkfactor, columns, i),
-                                       buffersize/forkfactor, preloadTime / forkfactor, kelondroTree.defaultObjectCachePercent);
-        }
-        ff = forkfactor;
         this.order = objectOrder;
-    }
-    
-    public static kelondroSplittedTree open(File pathToFiles, String filenameStub, kelondroOrder objectOrder,
-                    long buffersize, long preloadTime,
-                    int forkfactor, kelondroRow rowdef, int txtProps, int txtPropsWidth,
-                    boolean exitOnFail) throws IOException {
-        // generated a new splittet tree if it not exists or
-        // opens an existing one
-        if (existsAll(pathToFiles, filenameStub, forkfactor, rowdef.columns())) {
-            return new kelondroSplittedTree(pathToFiles, filenameStub, objectOrder, buffersize, preloadTime, forkfactor, rowdef.columns());
-        } else {
-            return new kelondroSplittedTree(pathToFiles, filenameStub, objectOrder,
-                            buffersize, preloadTime,
-                            forkfactor, rowdef, txtProps, txtPropsWidth,
-                            exitOnFail);
-        }
+        ff = forkfactor;
     }
     
     public void close() throws IOException {
diff --git a/source/de/anomic/kelondro/kelondroStack.java b/source/de/anomic/kelondro/kelondroStack.java
index d8ec9800b..02f936e1d 100644
--- a/source/de/anomic/kelondro/kelondroStack.java
+++ b/source/de/anomic/kelondro/kelondroStack.java
@@ -67,31 +67,33 @@ public final class kelondroStack extends kelondroRecords {
     protected static final int root  = 0; // pointer for FHandles-array: pointer to root node
     protected static final int toor  = 1; // pointer for FHandles-array: pointer to root node
 
-    public kelondroStack(File file, kelondroRow rowdef, boolean exitOnFail) {
+    public kelondroStack(File file, kelondroRow rowdef) throws IOException {
         // this creates a new stack
-        super(file, 0, 0, thisOHBytes, thisOHHandles, rowdef, thisFHandles, rowdef.columns() /* txtProps */, 80 /* txtPropWidth */, exitOnFail);
-        try {
+        super(file, 0, 0, thisOHBytes, thisOHHandles, rowdef, thisFHandles, rowdef.columns() /* txtProps */, 80 /* txtPropWidth */);
+        if (super.fileExisted) {
+            if ((getHandle(root) == null) && (getHandle(toor) == null)) clear();
+        } else {
             setHandle(root, null); // define the root value
             setHandle(toor, null); // define the toor value
-        } catch (IOException e) {
-            super.logFailure("cannot set root/toor handles / " + e.getMessage());
-            if (exitOnFail) System.exit(-1);
-            throw new RuntimeException("cannot set root/toor handles / " + e.getMessage());
         }
     }
 
-    public kelondroStack(File file) throws IOException{
-        // this opens a file with an existing stack
-        super(file, 0, 0);
-        if ((getHandle(root) == null) && (getHandle(toor) == null)) clear();
-    }
-
-    public void clear() throws IOException {
-        super.clear();
-        setHandle(root, null); // reset the root value
-        setHandle(toor, null); // reset the toor value
+    public static final kelondroStack open(File file, kelondroRow rowdef) {
+        try {
+            return new kelondroStack(file, rowdef);
+        } catch (IOException e) {
+            file.delete();
+            try {
+                return new kelondroStack(file, rowdef);
+            } catch (IOException ee) {
+                System.out.println("kelondroStack: cannot open or create file " + file.toString());
+                e.printStackTrace();
+                ee.printStackTrace();
+                return null;
+            }
+        }
     }
-
+    
     public static kelondroStack reset(kelondroStack stack) {
         // memorize settings to this file
         File f = new File(stack.filename);
@@ -102,9 +104,15 @@ public final class kelondroStack extends kelondroRecords {
         if (f.exists()) f.delete();
 
         // re-open a database with same settings as before
-        return new kelondroStack(f, row, true);
+        return open(f, row);
     }
     
+    public void clear() throws IOException {
+        super.clear();
+        setHandle(root, null); // reset the root value
+        setHandle(toor, null); // reset the toor value
+    }
+
     public class Counter implements Iterator {
         Handle nextHandle = null;
 
@@ -356,18 +364,19 @@ public final class kelondroStack extends kelondroRecords {
 	for (int i = 0; i < args.length; i++) System.out.print(args[i] + " ");
 	System.out.println("");
 	byte[] ret = null;
+    kelondroRow lens = new kelondroRow("byte[] key-" + Integer.parseInt(args[1]) + ", byte[] value-" + Integer.parseInt(args[2]));
 	try {
 	    if ((args.length > 4) || (args.length < 2)) {
 		System.err.println("usage: kelondroStack -c|-p|-v|-g|-i|-s [file]|[key [value]] <db-file>");
 		System.err.println("( create, push, view, (g)pop, imp, shell)");
 		System.exit(0);
 	    } else if (args.length == 2) {
-		kelondroStack fm = new kelondroStack(new File(args[1]));
+		kelondroStack fm = new kelondroStack(new File(args[1]), lens);
 		if (args[0].equals("-v")) {
 		    fm.print();
 		    ret = null;
 		} else if (args[0].equals("-g")) {
-		    fm = new kelondroStack(new File(args[1]));
+		    fm = new kelondroStack(new File(args[1]), lens);
 		    kelondroRow.Entry ret2 = fm.pop();
 		    ret = ((ret2 == null) ? null : ret2.getColBytes(1)); 
 		    fm.close();
@@ -375,7 +384,7 @@ public final class kelondroStack extends kelondroRecords {
 		fm.close();
 	    } else if (args.length == 3) {
 		if (args[0].equals("-i")) {
-		    kelondroStack fm = new kelondroStack(new File(args[2]));
+		    kelondroStack fm = new kelondroStack(new File(args[2]), lens);
 		    int i = fm.imp(new File(args[1]),";");
 		    fm.close();
 		    ret = (i + " records imported").getBytes();
@@ -399,7 +408,7 @@ public final class kelondroStack extends kelondroRecords {
                 if (f != null) try {f.close();}catch(Exception e) {}
             }
 		} else if (args[0].equals("-g")) {
-		    kelondroStack fm = new kelondroStack(new File(args[2]));
+		    kelondroStack fm = new kelondroStack(new File(args[2]), lens);
             kelondroRow.Entry ret2 = fm.pop(Integer.parseInt(args[1]));
 		    ret = ((ret2 == null) ? null : ret2.getColBytes(1)); 
 		    fm.close();
@@ -409,11 +418,10 @@ public final class kelondroStack extends kelondroRecords {
 		    // create <keylen> <valuelen> <filename>
 		    File f = new File(args[3]);
 		    if (f.exists()) f.delete();
-		    kelondroRow lens = new kelondroRow("byte[] key-" + Integer.parseInt(args[1]) + ", byte[] value-" + Integer.parseInt(args[2]));
-		    kelondroStack fm = new kelondroStack(f, lens, true);
+		    kelondroStack fm = new kelondroStack(f, lens);
 		    fm.close();
 		} else if (args[0].equals("-p")) {
-		    kelondroStack fm = new kelondroStack(new File(args[3]));
+		    kelondroStack fm = new kelondroStack(new File(args[3]), lens);
 		    fm.push(fm.row().newEntry(new byte[][] {args[1].getBytes(), args[2].getBytes()}));
 		    fm.close();
 		}
diff --git a/source/de/anomic/kelondro/kelondroTree.java b/source/de/anomic/kelondro/kelondroTree.java
index 266a54063..dc931451c 100644
--- a/source/de/anomic/kelondro/kelondroTree.java
+++ b/source/de/anomic/kelondro/kelondroTree.java
@@ -91,30 +91,55 @@ public class kelondroTree extends kelondroRecords implements kelondroIndex {
     protected       long                lastIteratorCount = readAheadChunkSize;
     private         kelondroObjectCache objectCache;
 
-    public kelondroTree(File file, long buffersize, long preloadTime, int objectCachePercent, kelondroRow rowdef, boolean exitOnFail) {
-        // this creates a new tree file
-        this(file, buffersize, preloadTime, objectCachePercent, rowdef, new kelondroNaturalOrder(true), rowdef.columns() /* txtProps */, 80 /* txtPropWidth */, exitOnFail);
+    public kelondroTree(File file, long buffersize, long preloadTime, int objectCachePercent, kelondroRow rowdef) throws IOException {
+        this(file, buffersize, preloadTime, objectCachePercent, rowdef, new kelondroNaturalOrder(true), rowdef.columns() /* txtProps */, 80 /* txtPropWidth */);
     }
 
-    public kelondroTree(File file, long buffersize, long preloadTime, int objectCachePercent, kelondroRow rowdef, kelondroOrder objectOrder, int txtProps, int txtPropsWidth, boolean exitOnFail) {
-        // this creates a new tree file
+    public kelondroTree(File file, long buffersize, long preloadTime, int objectCachePercent, kelondroRow rowdef,
+                        kelondroOrder objectOrder, int txtProps, int txtPropsWidth) throws IOException {
+        // opens an existing tree file or creates a new tree file
         super(file,
               (100 - objectCachePercent) * buffersize / 100, preloadTime,
               thisOHBytes, thisOHHandles, rowdef,
-              thisFHandles, txtProps, txtPropsWidth, exitOnFail);
-        try {
+              thisFHandles, txtProps, txtPropsWidth);
+        
+        super.setLogger(log);
+        if (super.fileExisted) {
+            this.objectOrder = objectOrder;
+            kelondroOrder oldOrder = readOrderType();
+            if ((oldOrder != null) && (!(oldOrder.equals(objectOrder)))) throw new IOException("wrong object order upon initialization. new order is " + objectOrder.toString() + ", old order was " + oldOrder.toString());
+        } else {
+            // create new file structure
             setHandle(root, null); // define the root value
-        } catch (IOException e) {
-            super.logFailure("cannot set root handle / " + e.getMessage());
-            if (exitOnFail) System.exit(-1);
-            throw new RuntimeException("cannot set root handle / " + e.getMessage());
+            this.objectOrder = objectOrder;
+            writeOrderType();            
         }
-        this.objectOrder = objectOrder;
-        writeOrderType();
-        super.setLogger(log);
         initObjectCache(buffersize, objectCachePercent);
     }
     
+    public static final kelondroTree open(File file, long buffersize, long preloadTime, int objectCachePercent, kelondroRow rowdef) {
+        return open(file, buffersize, preloadTime, objectCachePercent, rowdef, new kelondroNaturalOrder(true), rowdef.columns() /* txtProps */, 80 /* txtPropWidth */);
+    }
+    
+    public static final kelondroTree open(File file, long buffersize, long preloadTime, int objectCachePercent, kelondroRow rowdef,
+                        kelondroOrder objectOrder, int txtProps, int txtPropsWidth) {
+        // opens new or existing file; in case that any error occur the file is deleted again and it is tried to create the file again
+        // if that fails, the method returns null
+        try {
+            return new kelondroTree(file, buffersize, preloadTime, objectCachePercent, rowdef, objectOrder, txtProps, txtPropsWidth);
+        } catch (IOException e) {
+            file.delete();
+            try {
+                return new kelondroTree(file, buffersize, preloadTime, objectCachePercent, rowdef, objectOrder, txtProps, txtPropsWidth);
+            } catch (IOException ee) {
+                log.severe("cannot open or create file " + file.toString());
+                e.printStackTrace();
+                ee.printStackTrace();
+                return null;
+            }
+        }
+    }
+    
     public kelondroTree(kelondroRA ra, long buffersize, long preloadTime, int objectCachePercent, kelondroRow rowdef, boolean exitOnFail) {
         // this creates a new tree within a kelondroRA
         this(ra, buffersize, preloadTime, objectCachePercent, rowdef, new kelondroNaturalOrder(true), rowdef.columns() /* txtProps */, 80 /* txtPropWidth */, exitOnFail);
@@ -139,14 +164,6 @@ public class kelondroTree extends kelondroRecords implements kelondroIndex {
         initObjectCache(buffersize, objectCachePercent);
     }
     
-    public kelondroTree(File file, long buffersize, long preloadTime, int objectCachePercent) throws IOException {
-        // this opens a file with an existing tree file
-        super(file, (100 - objectCachePercent) * buffersize / 100, preloadTime);
-        readOrderType();
-        super.setLogger(log);
-        initObjectCache(buffersize, objectCachePercent);
-    }
-    
     public kelondroTree(kelondroRA ra, long buffersize, long preloadTime, int objectCachePercent) throws IOException {
         // this opens a file with an existing tree in a kelondroRA
         super(ra, (100 - objectCachePercent) * buffersize / 100, preloadTime);
@@ -183,12 +200,14 @@ public class kelondroTree extends kelondroRecords implements kelondroIndex {
         } catch (IOException e) {}
     }
     
-    private void readOrderType() {
+    private kelondroOrder readOrderType() {
         try {
             byte[] d = super.getDescription();
             String s = new String(d).substring(0, 2);
-            this.objectOrder = orderBySignature(s);
-        } catch (IOException e) {}
+            return orderBySignature(s);
+        } catch (IOException e) {
+            return null;
+        }
     }
     
     public static kelondroOrder orderBySignature(String signature) {
@@ -1238,7 +1257,7 @@ public class kelondroTree extends kelondroRecords implements kelondroIndex {
                     // test script
                     File testFile = new File("test.db");
                     while (testFile.exists()) testFile.delete();
-                    kelondroTree fm = new kelondroTree(testFile, 0x100000, 0, 10, new kelondroRow("byte[] a-4, byte[] b-4"), true);
+                    kelondroTree fm = new kelondroTree(testFile, 0x100000, 0, 10, new kelondroRow("byte[] a-4, byte[] b-4"));
                     byte[] dummy = "".getBytes();
                     fm.put("abc0".getBytes(), dummy); fm.put("bcd0".getBytes(), dummy);
                     fm.put("def0".getBytes(), dummy); fm.put("bab0".getBytes(), dummy);
@@ -1260,7 +1279,7 @@ public class kelondroTree extends kelondroRecords implements kelondroIndex {
 		    ret = null;
 		}
 	    } else if (args.length == 2) {
-		kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000, 0, 10);
+		kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000, 0, 10, new kelondroRow("byte[] a-4, byte[] b-4"));
 		if (args[0].equals("-v")) {
 		    fm.print();
 		    ret = null;
@@ -1268,11 +1287,11 @@ public class kelondroTree extends kelondroRecords implements kelondroIndex {
 		fm.close();
 	    } else if (args.length == 3) {
 		if (args[0].equals("-d")) {
-		    kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000, 0, 10);
+		    kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000, 0, 10, new kelondroRow("byte[] a-4, byte[] b-4"));
 		    fm.remove(args[2].getBytes());
 		    fm.close();
 		} else if (args[0].equals("-i")) {
-		    kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000, 0, 10);
+		    kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000, 0, 10, new kelondroRow("byte[] a-4, byte[] b-4"));
 		    int i = fm.imp(new File(args[1]),";");
 		    fm.close();
 		    ret = (i + " records imported").getBytes();
@@ -1295,12 +1314,12 @@ public class kelondroTree extends kelondroRecords implements kelondroIndex {
                 if (f != null) try {f.close();}catch(Exception e){}
             }
 		} else if (args[0].equals("-g")) {
-		    kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000, 0, 10);
+		    kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000, 0, 10, new kelondroRow("byte[] a-4, byte[] b-4"));
 		    kelondroRow.Entry ret2 = fm.get(args[2].getBytes());
 		    ret = ((ret2 == null) ? null : ret2.getColBytes(1)); 
 		    fm.close();
 		} else if (args[0].equals("-n")) {
-		    kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000, 0, 10);
+		    kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000, 0, 10, new kelondroRow("byte[] a-4, byte[] b-4"));
 		    //byte[][] keys = fm.getSequentialKeys(args[2].getBytes(), 500, true);
                     Iterator rowIt = fm.rows(true, false, (args[2].length() == 0) ? null : args[2].getBytes());
                     Vector v = new Vector();
@@ -1314,10 +1333,10 @@ public class kelondroTree extends kelondroRecords implements kelondroIndex {
 		    File f = new File(args[3]);
 		    if (f.exists()) f.delete();
             kelondroRow lens = new kelondroRow("byte[] key-" + Integer.parseInt(args[1]) + ", byte[] value-" + Integer.parseInt(args[2]));
-		    kelondroTree fm = new kelondroTree(f, 0x100000, 0, 10, lens, true);
+		    kelondroTree fm = new kelondroTree(f, 0x100000, 0, 10, lens);
 		    fm.close();
 		} else if (args[0].equals("-u")) {
-		    kelondroTree fm = new kelondroTree(new File(args[3]), 0x100000, 0, 10);
+		    kelondroTree fm = new kelondroTree(new File(args[1]), 0x100000, 0, 10, new kelondroRow("byte[] a-4, byte[] b-4"));
 		    ret = fm.put(args[1].getBytes(), args[2].getBytes());
 		    fm.close();
 		}
@@ -1380,7 +1399,7 @@ public class kelondroTree extends kelondroRecords implements kelondroIndex {
             int steps = 0;
             while (true) {
                 if (testFile.exists()) testFile.delete();
-                tt = new kelondroTree(testFile, 200, 0, 10, new kelondroRow("byte[] a-4, byte[] b-4"), true);
+                tt = new kelondroTree(testFile, 200, 0, 10, new kelondroRow("byte[] a-4, byte[] b-4"));
                 steps = 10 + ((int) System.currentTimeMillis() % 7) * (((int) System.currentTimeMillis() + 17) % 11);
                 t = s;
                 d = "";
@@ -1446,7 +1465,7 @@ public class kelondroTree extends kelondroRecords implements kelondroIndex {
         File f = new File("test.db");
         if (f.exists()) f.delete();
         try {
-            kelondroTree tt = new kelondroTree(f, 1000, 0, 10, new kelondroRow("byte[] a-4, byte[] b-4"), true);
+            kelondroTree tt = new kelondroTree(f, 1000, 0, 10, new kelondroRow("byte[] a-4, byte[] b-4"));
             byte[] b;
             b = testWord('B'); tt.put(b, b); //tt.print();
             b = testWord('C'); tt.put(b, b); //tt.print();
@@ -1511,7 +1530,7 @@ public class kelondroTree extends kelondroRecords implements kelondroIndex {
     
     public static kelondroTree testTree(File f, String testentities) throws IOException {
         if (f.exists()) f.delete();
-        kelondroTree tt = new kelondroTree(f, 0, 0, 10, new kelondroRow("byte[] a-4, byte[] b-4"), true);
+        kelondroTree tt = new kelondroTree(f, 0, 0, 10, new kelondroRow("byte[] a-4, byte[] b-4"));
         byte[] b;
         for (int i = 0; i < testentities.length(); i++) {
             b = testWord(testentities.charAt(i));
diff --git a/source/de/anomic/plasma/plasmaCrawlBalancer.java b/source/de/anomic/plasma/plasmaCrawlBalancer.java
index 66cf346f1..7b68e563a 100644
--- a/source/de/anomic/plasma/plasmaCrawlBalancer.java
+++ b/source/de/anomic/plasma/plasmaCrawlBalancer.java
@@ -59,15 +59,7 @@ public class plasmaCrawlBalancer {
     private HashMap domainStacks;
     
     public plasmaCrawlBalancer(File stackFile) {
-        if (stackFile.exists()) {
-            try {
-                stack = new kelondroStack(stackFile);
-            } catch (IOException e) {
-                stack = new kelondroStack(stackFile, new kelondroRow("byte[] urlhash-" + indexURL.urlHashLength), true);
-            }
-        } else {
-            stack = new kelondroStack(stackFile, new kelondroRow("byte[] urlhash-" + indexURL.urlHashLength), true);
-        }
+        stack = kelondroStack.open(stackFile, new kelondroRow("byte[] urlhash-" + indexURL.urlHashLength));
         domainStacks = new HashMap();
     }
 
diff --git a/source/de/anomic/plasma/plasmaCrawlEURL.java b/source/de/anomic/plasma/plasmaCrawlEURL.java
index f4e96d681..fdd097907 100644
--- a/source/de/anomic/plasma/plasmaCrawlEURL.java
+++ b/source/de/anomic/plasma/plasmaCrawlEURL.java
@@ -57,8 +57,8 @@ import java.util.Iterator;
 
 import de.anomic.index.indexURL;
 import de.anomic.kelondro.kelondroBase64Order;
+import de.anomic.kelondro.kelondroFlexTable;
 import de.anomic.kelondro.kelondroRow;
-import de.anomic.kelondro.kelondroTree;
 import de.anomic.tools.bitfield;
 
 public class plasmaCrawlEURL extends indexURL {
@@ -138,19 +138,32 @@ public class plasmaCrawlEURL extends indexURL {
             "String failcause-"    + urlErrorLength  + ", " +        // string describing load failure
             "byte[] flags-"        + urlFlagLength);                 // extra space
 
-        if (cachePath.exists()) try {
+       
+        String newCacheName = "urlErr3.table";
+        cachePath.mkdirs();
+        try {
+            urlHashCache = new kelondroFlexTable(cachePath, newCacheName, kelondroBase64Order.enhancedCoder, bufferkb * 0x400, preloadTime, rowdef);
+        } catch (IOException e) {
+            e.printStackTrace();
+            System.exit(-1);
+        }
+        
+        /*
+        File oldCacheFile = new File(cachePath, "urlErr0.db");
+        if (oldCacheFile.exists()) try {
             // open existing cache
-            kelondroTree tree = new kelondroTree(cachePath, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent);
+            kelondroTree tree = new kelondroTree(oldCacheFile, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent);
             tree.assignRowdef(rowdef);
             urlHashCache = tree;
         } catch (IOException e) {
-            cachePath.delete();
-            urlHashCache = new kelondroTree(cachePath, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, rowdef, true);
+            oldCacheFile.delete();
+            urlHashCache = new kelondroTree(oldCacheFile, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, rowdef, true);
         } else {
             // create new cache
-            cachePath.getParentFile().mkdirs();
-            urlHashCache = new kelondroTree(cachePath, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, rowdef, true);
+            oldCacheFile.getParentFile().mkdirs();
+            urlHashCache = new kelondroTree(oldCacheFile, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, rowdef, true);
         }
+        */
     }
 
     public synchronized Entry newEntry(URL url, String referrer, String initiator, String executor,
diff --git a/source/de/anomic/plasma/plasmaCrawlLURL.java b/source/de/anomic/plasma/plasmaCrawlLURL.java
index 424d9f223..ccbe80c8b 100644
--- a/source/de/anomic/plasma/plasmaCrawlLURL.java
+++ b/source/de/anomic/plasma/plasmaCrawlLURL.java
@@ -113,20 +113,14 @@ public final class plasmaCrawlLURL extends indexURL {
             "Cardinal size-"       + urlSizeLength      + " {b64e}, " + // size of file in bytes
             "Cardinal wc-"         + urlWordCountLength + " {b64e}");   // word count
 
-        if (cachePath.exists()) {
-            // open existing cache
-            try {
-                kelondroTree tree = new kelondroTree(cachePath, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent);
-                tree.assignRowdef(rowdef);
-                urlHashCache = tree;
-            } catch (IOException e) {
-                cachePath.getParentFile().mkdirs();
-                urlHashCache = new kelondroTree(cachePath, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, rowdef, true);
-            }
-        } else {
-            // create new cache
-            cachePath.getParentFile().mkdirs();
-            urlHashCache = new kelondroTree(cachePath, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, rowdef, true);
+        File cacheFile = new File(cachePath, "urlHash.db");
+        
+        cacheFile.getParentFile().mkdirs();
+        try {
+            urlHashCache = new kelondroTree(cacheFile, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, rowdef);
+        } catch (IOException e) {
+            e.printStackTrace();
+            System.exit(-1);
         }
 
         // init result stacks
diff --git a/source/de/anomic/plasma/plasmaCrawlNURL.java b/source/de/anomic/plasma/plasmaCrawlNURL.java
index a1239185a..88c0e8d06 100644
--- a/source/de/anomic/plasma/plasmaCrawlNURL.java
+++ b/source/de/anomic/plasma/plasmaCrawlNURL.java
@@ -55,9 +55,9 @@ import java.util.Iterator;
 import de.anomic.index.indexURL;
 import de.anomic.kelondro.kelondroBase64Order;
 import de.anomic.kelondro.kelondroException;
+import de.anomic.kelondro.kelondroFlexTable;
 import de.anomic.kelondro.kelondroRecords;
 import de.anomic.kelondro.kelondroStack;
-import de.anomic.kelondro.kelondroTree;
 import de.anomic.kelondro.kelondroRow;
 import de.anomic.server.logging.serverLog;
 import de.anomic.tools.bitfield;
@@ -104,50 +104,32 @@ public class plasmaCrawlNURL extends indexURL {
     private long preloadTime;
     initStackIndex initThead;
     
-    public plasmaCrawlNURL(File cacheStacksPath, int bufferkb, long preloadTime) {
+    public plasmaCrawlNURL(File cachePath, int bufferkb, long preloadTime) {
         super();
-        this.cacheStacksPath = cacheStacksPath;
+        this.cacheStacksPath = cachePath;
         this.bufferkb = bufferkb;
         this.preloadTime = preloadTime;
         
         // create a stack for newly entered entries
-        if (!(cacheStacksPath.exists())) cacheStacksPath.mkdir(); // make the path
+        if (!(cachePath.exists())) cachePath.mkdir(); // make the path
 
         openHashCache();
 
-        File coreStackFile = new File(cacheStacksPath, "urlNoticeLocal0.stack");
-        File limitStackFile = new File(cacheStacksPath, "urlNoticeLimit0.stack");
-        File overhangStackFile = new File(cacheStacksPath, "urlNoticeOverhang0.stack");
-        File remoteStackFile = new File(cacheStacksPath, "urlNoticeRemote0.stack");
-        File imageStackFile = new File(cacheStacksPath, "urlNoticeImage0.stack");
-        File movieStackFile = new File(cacheStacksPath, "urlNoticeMovie0.stack");
-        File musicStackFile = new File(cacheStacksPath, "urlNoticeMusic0.stack");
+        File coreStackFile = new File(cachePath, "urlNoticeLocal0.stack");
+        File limitStackFile = new File(cachePath, "urlNoticeLimit0.stack");
+        File overhangStackFile = new File(cachePath, "urlNoticeOverhang0.stack");
+        File remoteStackFile = new File(cachePath, "urlNoticeRemote0.stack");
+        File imageStackFile = new File(cachePath, "urlNoticeImage0.stack");
+        File movieStackFile = new File(cachePath, "urlNoticeMovie0.stack");
+        File musicStackFile = new File(cachePath, "urlNoticeMusic0.stack");
         coreStack = new plasmaCrawlBalancer(coreStackFile);
         limitStack = new plasmaCrawlBalancer(limitStackFile);
         overhangStack = new plasmaCrawlBalancer(overhangStackFile);
         remoteStack = new plasmaCrawlBalancer(remoteStackFile);
         kelondroRow rowdef = new kelondroRow("byte[] urlhash-" + indexURL.urlHashLength);
-        if (imageStackFile.exists()) try {
-            imageStack = new kelondroStack(imageStackFile);
-        } catch (IOException e) {
-            imageStack = new kelondroStack(imageStackFile, rowdef, true);
-        } else {
-            imageStack = new kelondroStack(imageStackFile, rowdef, true);
-        }
-        if (movieStackFile.exists()) try {
-            movieStack = new kelondroStack(movieStackFile);
-        } catch (IOException e) {
-            movieStack = new kelondroStack(movieStackFile, rowdef, true);
-        } else {
-            movieStack = new kelondroStack(movieStackFile, rowdef, true);
-        }
-        if (musicStackFile.exists()) try {
-            musicStack = new kelondroStack(musicStackFile);
-        } catch (IOException e) {
-            musicStack = new kelondroStack(musicStackFile, rowdef, true);
-        } else {
-            musicStack = new kelondroStack(musicStackFile, rowdef, true);
-        }
+        imageStack = kelondroStack.open(imageStackFile, rowdef);
+        movieStack = kelondroStack.open(movieStackFile, rowdef);
+        musicStack = kelondroStack.open(musicStackFile, rowdef);
 
         // init stack Index
         stackIndex = new HashSet();
@@ -165,15 +147,17 @@ public class plasmaCrawlNURL extends indexURL {
     }
     
     private void openHashCache() {
-        File oldCacheFile = new File(cacheStacksPath, "urlNotice1.db");
-        //File newCacheFile = new File(cacheStacksPath, "urlNotice2.table");
-        /*if (newCacheFile.exists()) try {
-            urlHashCache = new kelondroFlexTable(cacheStacksPath, "urlNotice2.table", kelondroBase64Order.enhancedCoder, bufferkb * 0x400, preloadTime, rowdef, true);
+        String newCacheName = "urlNotice3.table";
+        cacheStacksPath.mkdirs();
+        try {
+            urlHashCache = new kelondroFlexTable(cacheStacksPath, newCacheName, kelondroBase64Order.enhancedCoder, bufferkb * 0x400, preloadTime, rowdef);
         } catch (IOException e) {
             e.printStackTrace();
-            oldCacheFile.delete();
-            urlHashCache = new kelondroTree(oldCacheFile, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, rowdef, true);
-        } else*/ if (oldCacheFile.exists()) try {
+            System.exit(-1);
+        }
+        /*
+        File oldCacheFile = new File(cacheStacksPath, "urlNotice1.db");
+        if (oldCacheFile.exists()) try {
             // open existing cache
             kelondroTree tree = new kelondroTree(oldCacheFile, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent);
             tree.assignRowdef(rowdef);
@@ -184,9 +168,9 @@ public class plasmaCrawlNURL extends indexURL {
         } else {
             // create new cache
             oldCacheFile.getParentFile().mkdirs();
-            //urlHashCache = new kelondroFlexTable(cacheStacksPath, "urlNotice2.table", kelondroBase64Order.enhancedCoder, bufferkb * 0x400, preloadTime, rowdef, true);
             urlHashCache = new kelondroTree(oldCacheFile, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, rowdef, true);
         }
+         */
     }
     
     private void resetHashCache() {
@@ -200,6 +184,7 @@ public class plasmaCrawlNURL extends indexURL {
     }
     
     public void close() {
+        try {urlHashCache.close();} catch (IOException e) {}
         coreStack.close();
         limitStack.close();
         overhangStack.close();
@@ -552,6 +537,8 @@ public class plasmaCrawlNURL extends indexURL {
                     this.flags.getBytes(),
                     normalizeHandle(this.handle).getBytes()
                 };
+                if (urlHashCache == null) System.out.println("urlHashCache is NULL");
+                if ((urlHashCache != null) && (urlHashCache.row() == null)) System.out.println("row() is NULL");
                 urlHashCache.put(urlHashCache.row().newEntry(entry));
                 this.stored = true;
             } catch (IOException e) {
diff --git a/source/de/anomic/plasma/plasmaCrawlProfile.java b/source/de/anomic/plasma/plasmaCrawlProfile.java
index 1eb05cb4f..e14c3dee0 100644
--- a/source/de/anomic/plasma/plasmaCrawlProfile.java
+++ b/source/de/anomic/plasma/plasmaCrawlProfile.java
@@ -67,16 +67,8 @@ public class plasmaCrawlProfile {
         this.profileTableFile = file;
         this.bufferkb = bufferkb;
         this.preloadTime = preloadTime;
-        kelondroDyn dyn = null;
-        if (profileTableFile.exists()) try {
-            dyn = new kelondroDyn(file, bufferkb * 1024, preloadTime, '#');
-        } catch (IOException e) {
-            profileTableFile.delete();
-            dyn = new kelondroDyn(file, bufferkb * 1024, preloadTime, indexURL.urlCrawlProfileHandleLength, 2000, '#', true);
-        } else {
-            profileTableFile.getParentFile().mkdirs();
-            dyn = new kelondroDyn(file, bufferkb * 1024, preloadTime, indexURL.urlCrawlProfileHandleLength, 2000, '#', true);
-        }
+        profileTableFile.getParentFile().mkdirs();
+        kelondroDyn dyn = kelondroDyn.open(profileTableFile, bufferkb * 1024, preloadTime, indexURL.urlCrawlProfileHandleLength, 2000, '#');
         profileTable = new kelondroMap(dyn);
         domsCache = new HashMap();
     }
@@ -102,7 +94,8 @@ public class plasmaCrawlProfile {
         if (profileTable != null) try { profileTable.close(); } catch (IOException e) {}
         if (!(profileTableFile.delete())) throw new RuntimeException("cannot delete crawl profile database");
         profileTableFile.getParentFile().mkdirs();
-        profileTable = new kelondroMap(new kelondroDyn(profileTableFile, bufferkb * 1024, preloadTime, indexURL.urlCrawlProfileHandleLength, 2000, '#', true));
+        kelondroDyn dyn = kelondroDyn.open(profileTableFile, bufferkb * 1024, preloadTime, indexURL.urlCrawlProfileHandleLength, 2000, '#');
+        profileTable = new kelondroMap(dyn);
     }
     
     public void close() {
diff --git a/source/de/anomic/plasma/plasmaCrawlRobotsTxt.java b/source/de/anomic/plasma/plasmaCrawlRobotsTxt.java
index ccf756954..bb301be63 100644
--- a/source/de/anomic/plasma/plasmaCrawlRobotsTxt.java
+++ b/source/de/anomic/plasma/plasmaCrawlRobotsTxt.java
@@ -71,20 +71,8 @@ public class plasmaCrawlRobotsTxt {
         this.robotsTableFile = robotsTableFile;
         this.bufferkb = bufferkb;
         this.preloadTime = preloadTime;
-        if (robotsTableFile.exists()) {
-            try {
-                robotsTable = new kelondroMap(new kelondroDyn(robotsTableFile, bufferkb * 1024, preloadTime, '_'));
-            } catch (kelondroException e) {
-                robotsTableFile.delete();
-                robotsTable = new kelondroMap(new kelondroDyn(robotsTableFile, bufferkb * 1024, preloadTime, 256, 512, '_', true));
-            } catch (IOException e) {
-                robotsTableFile.delete();
-                robotsTable = new kelondroMap(new kelondroDyn(robotsTableFile, bufferkb * 1024, preloadTime, 256, 512, '_', true));
-            }
-        } else {
-            robotsTableFile.getParentFile().mkdirs();
-            robotsTable = new kelondroMap(new kelondroDyn(robotsTableFile, bufferkb * 1024, preloadTime, 256, 512, '_', true));
-        }
+        robotsTableFile.getParentFile().mkdirs();
+        robotsTable = new kelondroMap(kelondroDyn.open(robotsTableFile, bufferkb * 1024, preloadTime, 256, 512, '_'));
     }
     
     public int cacheNodeChunkSize() {
@@ -110,7 +98,7 @@ public class plasmaCrawlRobotsTxt {
         } catch (IOException e) {}
         if (!(robotsTableFile.delete())) throw new RuntimeException("cannot delete robots.txt database");
         robotsTableFile.getParentFile().mkdirs();
-        robotsTable = new kelondroMap(new kelondroDyn(robotsTableFile, this.bufferkb, preloadTime, 256, 512, '_', true));
+        robotsTable = new kelondroMap(kelondroDyn.open(robotsTableFile, this.bufferkb, preloadTime, 256, 512, '_'));
     }
     
     public void close() {
diff --git a/source/de/anomic/plasma/plasmaCrawlStacker.java b/source/de/anomic/plasma/plasmaCrawlStacker.java
index ceb6224ff..9d5b910b8 100644
--- a/source/de/anomic/plasma/plasmaCrawlStacker.java
+++ b/source/de/anomic/plasma/plasmaCrawlStacker.java
@@ -202,7 +202,7 @@ public final class plasmaCrawlStacker {
             Date loadDate, 
             int currentdepth, 
             plasmaCrawlProfile.entry profile) {
-        try {            
+        if (profile != null) try {            
             this.queue.addMessage(new stackCrawlMessage(
                     initiatorHash,
                     nexturlString,
@@ -579,6 +579,9 @@ public final class plasmaCrawlStacker {
         private final serverSemaphore writeSync;
         private final LinkedList urlEntryHashCache;
         private kelondroTree urlEntryCache;
+        private File cacheStacksPath;
+        private int bufferkb;
+        private long preloadTime;
         
         public stackCrawlQueue(File cacheStacksPath, int bufferkb, long preloadTime) {
             // init the read semaphore
@@ -591,54 +594,54 @@ public final class plasmaCrawlStacker {
             this.urlEntryHashCache = new LinkedList();
             
             // create a stack for newly entered entries
-            if (!(cacheStacksPath.exists())) cacheStacksPath.mkdir(); // make the path
+            this.cacheStacksPath = cacheStacksPath;
+            this.bufferkb = bufferkb;
+            this.preloadTime = preloadTime;
 
-            File cacheFile = new File(cacheStacksPath, "urlPreNotice.db");
-            if (cacheFile.exists()) {
-                // open existing cache
-                try {
-                    kelondroTree tree = new kelondroTree(cacheFile, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent);
-                    tree.assignRowdef(plasmaCrawlNURL.rowdef);
-                    this.urlEntryCache = tree;
-                } catch (IOException e) {
-                    cacheFile.delete();
-                    this.urlEntryCache = new kelondroTree(cacheFile, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, plasmaCrawlNURL.rowdef, true);
-                }
-                try {
-                    // loop through the list and fill the messageList with url hashs
-                    Iterator rows = this.urlEntryCache.rows(true, false, null);
-                    kelondroRow.Entry entry;
-                    while (rows.hasNext()) {
-                        entry = (kelondroRow.Entry) rows.next();
-                        if (entry == null) {
-                            System.out.println("ERROR! null element found");
-                            continue;
-                        }
-                        this.urlEntryHashCache.add(entry.getColString(0, null));
-                        this.readSync.V();
+            openDB();
+            try {
+                // loop through the list and fill the messageList with url hashs
+                Iterator rows = this.urlEntryCache.rows(true, false, null);
+                kelondroRow.Entry entry;
+                while (rows.hasNext()) {
+                    entry = (kelondroRow.Entry) rows.next();
+                    if (entry == null) {
+                        System.out.println("ERROR! null element found");
+                        continue;
                     }
-                } catch (kelondroException e) {
-                    /* if we have an error, we start with a fresh database */
-                    plasmaCrawlStacker.this.log.logSevere("Unable to initialize crawl stacker queue, kelondroException:" + e.getMessage() + ". Reseting DB.\n",e);
-                    
-                    // deleting old db and creating a new db
-                    try {this.urlEntryCache.close();}catch(Exception ex){}
-                    cacheFile.delete();
-                    this.urlEntryCache = new kelondroTree(cacheFile, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, plasmaCrawlNURL.rowdef, true);
-                } catch (IOException e) {
-                    /* if we have an error, we start with a fresh database */
-                    plasmaCrawlStacker.this.log.logSevere("Unable to initialize crawl stacker queue, IOException:" + e.getMessage() + ". Reseting DB.\n",e);
-                    
-                    // deleting old db and creating a new db
-                    try {this.urlEntryCache.close();}catch(Exception ex){}
-                    cacheFile.delete();
-                    this.urlEntryCache = new kelondroTree(cacheFile, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, plasmaCrawlNURL.rowdef, true);
+                    this.urlEntryHashCache.add(entry.getColString(0, null));
+                    this.readSync.V();
                 }
-            } else {
-                // create new cache
-                cacheFile.getParentFile().mkdirs();
-                this.urlEntryCache = new kelondroTree(cacheFile, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, plasmaCrawlNURL.rowdef, true);
+            } catch (kelondroException e) {
+                /* if we have an error, we start with a fresh database */
+                plasmaCrawlStacker.this.log.logSevere("Unable to initialize crawl stacker queue, kelondroException:" + e.getMessage() + ". Reseting DB.\n", e);
+
+                // deleting old db and creating a new db
+                try {this.urlEntryCache.close();} catch (Exception ex) {}
+                deleteDB();
+                openDB();
+            } catch (IOException e) {
+                /* if we have an error, we start with a fresh database */
+                plasmaCrawlStacker.this.log.logSevere("Unable to initialize crawl stacker queue, IOException:" + e.getMessage() + ". Reseting DB.\n", e);
+
+                // deleting old db and creating a new db
+                try {this.urlEntryCache.close();} catch (Exception ex) {}
+                deleteDB();
+                openDB();
             }
+
+        }
+        
+        private void deleteDB() {
+            File cacheFile = new File(cacheStacksPath, "urlPreNotice.db");
+            cacheFile.delete();
+        }
+        
+        private void openDB() {
+            if (!(cacheStacksPath.exists())) cacheStacksPath.mkdir(); // make the path
+            File cacheFile = new File(cacheStacksPath, "urlPreNotice.db");
+            cacheFile.getParentFile().mkdirs();
+            this.urlEntryCache = kelondroTree.open(cacheFile, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, plasmaCrawlNURL.rowdef);
         }
         
         public int cacheNodeChunkSize() {
diff --git a/source/de/anomic/plasma/plasmaHTCache.java b/source/de/anomic/plasma/plasmaHTCache.java
index 9baea0cc4..a1ed35f15 100644
--- a/source/de/anomic/plasma/plasmaHTCache.java
+++ b/source/de/anomic/plasma/plasmaHTCache.java
@@ -154,10 +154,7 @@ public final class plasmaHTCache {
         // open the response header database
         File dbfile = new File(this.cachePath, "responseHeader.db");
         try {
-            if (dbfile.exists())
-                this.responseHeaderDB = new kelondroMap(new kelondroDyn(dbfile, bufferkb * 0x400, preloadTime, '#'));
-            else
-                this.responseHeaderDB = new kelondroMap(new kelondroDyn(dbfile, bufferkb * 0x400, preloadTime, indexURL.urlHashLength, 150, '#', false));
+            this.responseHeaderDB = new kelondroMap(new kelondroDyn(dbfile, bufferkb * 0x400, preloadTime, indexURL.urlHashLength, 150, '#'));
         } catch (IOException e) {
             this.log.logSevere("the request header database could not be opened: " + e.getMessage());
             System.exit(0);
diff --git a/source/de/anomic/plasma/plasmaRankingCRProcess.java b/source/de/anomic/plasma/plasmaRankingCRProcess.java
index 983b9365c..92ed39a87 100644
--- a/source/de/anomic/plasma/plasmaRankingCRProcess.java
+++ b/source/de/anomic/plasma/plasmaRankingCRProcess.java
@@ -260,7 +260,7 @@ public class plasmaRankingCRProcess {
         kelondroCollectionIndex newseq = null;
         if (newdb) {
             File path = to_file.getParentFile(); // path to storage place
-            newacc = new kelondroFlexTable(path, CRG_accname, kelondroBase64Order.enhancedCoder, 128 * 1024 * 1024, -1, CRG_accrow, true);
+            newacc = new kelondroFlexTable(path, CRG_accname, kelondroBase64Order.enhancedCoder, 128 * 1024 * 1024, -1, CRG_accrow);
             newseq = new kelondroCollectionIndex(path, CRG_seqname, 12, kelondroBase64Order.enhancedCoder, 128 * 1024 * 1024, -1, 2, CRG_colrow);
         } else {
             if (!(to_file.exists())) {
diff --git a/source/de/anomic/plasma/plasmaSwitchboardQueue.java b/source/de/anomic/plasma/plasmaSwitchboardQueue.java
index 2fef55943..de6552a08 100644
--- a/source/de/anomic/plasma/plasmaSwitchboardQueue.java
+++ b/source/de/anomic/plasma/plasmaSwitchboardQueue.java
@@ -89,15 +89,7 @@ public class plasmaSwitchboardQueue {
                 "String profile-"      + indexURL.urlCrawlProfileHandleLength + ", " +        // the name of the prefetch profile handle
                 "String urldescr-"     + indexURL.urlDescrLength);                            //
             
-        if (sbQueueStackPath.exists()) try {
-            sbQueueStack = new kelondroStack(sbQueueStackPath);
-            sbQueueStack.assignRowdef(rowdef);
-        } catch (IOException e) {
-            sbQueueStackPath.delete();
-            sbQueueStack = new kelondroStack(sbQueueStackPath, rowdef, true);
-        } else {
-            sbQueueStack = new kelondroStack(sbQueueStackPath, rowdef, true);
-        }
+        sbQueueStack = kelondroStack.open(sbQueueStackPath, rowdef);
     }
     
     private void resetQueueStack() {
diff --git a/source/de/anomic/plasma/plasmaURLPool.java b/source/de/anomic/plasma/plasmaURLPool.java
index 4d1622b43..9221f39a2 100644
--- a/source/de/anomic/plasma/plasmaURLPool.java
+++ b/source/de/anomic/plasma/plasmaURLPool.java
@@ -58,9 +58,9 @@ public class plasmaURLPool {
     public  final plasmaCrawlEURL        errorURL;
     
     public plasmaURLPool(File plasmaPath, int ramLURL, int ramNURL, int ramEURL, long preloadTime) {
-        loadedURL = new plasmaCrawlLURL(new File(plasmaPath, "urlHash.db"), ramLURL, preloadTime);
+        loadedURL = new plasmaCrawlLURL(plasmaPath, ramLURL, preloadTime);
         noticeURL = new plasmaCrawlNURL(plasmaPath, ramNURL, -1);
-        errorURL = new plasmaCrawlEURL(new File(plasmaPath, "urlErr0.db"), ramEURL, -1);
+        errorURL = new plasmaCrawlEURL(plasmaPath, ramEURL, -1);
     }
     
     public String exists(String hash) {
diff --git a/source/de/anomic/plasma/plasmaWordConnotation.java b/source/de/anomic/plasma/plasmaWordConnotation.java
index 664b7bea1..a982cdf33 100644
--- a/source/de/anomic/plasma/plasmaWordConnotation.java
+++ b/source/de/anomic/plasma/plasmaWordConnotation.java
@@ -58,14 +58,8 @@ public class plasmaWordConnotation {
     private static final int nodesize = 4048;
     private kelondroDynTree refDB;
     
-    public plasmaWordConnotation(File refDBfile, int bufferkb, long preloadTime, char fillChar) {
-        if (refDBfile.exists()) try {
-            refDB = new kelondroDynTree(refDBfile, bufferkb * 0x400, preloadTime, fillChar);
-        } catch (IOException e) {
-            refDB = new kelondroDynTree(refDBfile, bufferkb * 0x400, preloadTime, wordlength, nodesize, new kelondroRow("byte[] word-" + wordlength + ", Cardinal count-" + countlength), fillChar, true);
-        } else {
-            refDB = new kelondroDynTree(refDBfile, bufferkb * 0x400, preloadTime, wordlength, nodesize, new kelondroRow("byte[] word-" + wordlength + ", Cardinal count-" + countlength), fillChar, true);
-        }
+    public plasmaWordConnotation(File refDBfile, int bufferkb, long preloadTime, char fillChar) throws IOException {
+        refDB = new kelondroDynTree(refDBfile, bufferkb * 0x400, preloadTime, wordlength, nodesize, new kelondroRow("byte[] word-" + wordlength + ", Cardinal count-" + countlength), fillChar);
     }
 
     private void addSingleRef(String word, String reference) throws IOException {
diff --git a/source/de/anomic/plasma/plasmaWordIndexAssortment.java b/source/de/anomic/plasma/plasmaWordIndexAssortment.java
index c96ea305d..50732ddde 100644
--- a/source/de/anomic/plasma/plasmaWordIndexAssortment.java
+++ b/source/de/anomic/plasma/plasmaWordIndexAssortment.java
@@ -116,33 +116,16 @@ public final class plasmaWordIndexAssortment {
         this.bufferSize = bufferkb * 1024;
         this.preloadTime = preloadTime;
         this.log = log;
-        if (assortmentFile.exists()) {
-            // open existing assortment tree file
-            try {
-                long start = System.currentTimeMillis();
-                assortments = new kelondroTree(assortmentFile, bufferSize, preloadTime, kelondroTree.defaultObjectCachePercent);
-                assortments.assignRowdef(bufferStructure(assortmentLength));
-                long stop = System.currentTimeMillis();
-                if (log != null)
-                    log.logConfig("Opened Assortment, " +
+        // open assortment tree file
+        long start = System.currentTimeMillis();
+        assortments = kelondroTree.open(assortmentFile, bufferSize, preloadTime, kelondroTree.defaultObjectCachePercent, bufferStructure(assortmentLength));
+        long stop = System.currentTimeMillis();
+        if (log != null) log.logConfig("Opened Assortment, " +
                                   assortments.size() + " entries, width " +
                                   assortmentLength + ", " + bufferkb + "kb buffer, " +
                                   preloadTime + " ms preloadTime, " +
                                   (stop - start) + " ms effective, " +
                                   assortments.cacheNodeStatus()[1] + " preloaded"); 
-                return;
-            } catch (IOException e){
-                serverLog.logSevere("PLASMA", "unable to open assortment database " + assortmentLength + ", creating new: " + e.getMessage(), e);
-            } catch (IndexOutOfBoundsException e){
-                serverLog.logSevere("PLASMA", "assortment database " + assortmentLength + " corupted, creating new: " + e.getMessage(), e);
-            } catch (kelondroException e) {
-                serverLog.logSevere("PLASMA", "assortment database " + assortmentLength + " corupted, creating new: " + e.getMessage(), e);
-            }
-            assortmentFile.delete(); // make space for new one
-        }
-        // create new assortment tree file
-        assortments = new kelondroTree(assortmentFile, bufferSize, preloadTime, kelondroTree.defaultObjectCachePercent, bufferStructure(assortmentLength), true);
-        if (log != null) log.logConfig("Created new Assortment, width " + assortmentLength + ", " + bufferkb + "kb buffer");
     }
 
     public void store(indexContainer newContainer) {
@@ -269,7 +252,7 @@ public final class plasmaWordIndexAssortment {
             if (!(assortmentFile.delete())) throw new RuntimeException("cannot delete assortment database");
         }
         if (assortmentFile.exists()) assortmentFile.delete();
-        assortments = new kelondroTree(assortmentFile, bufferSize, preloadTime, kelondroTree.defaultObjectCachePercent, bufferStructure(assortmentLength), true);
+        assortments = kelondroTree.open(assortmentFile, bufferSize, preloadTime, kelondroTree.defaultObjectCachePercent, bufferStructure(assortmentLength));
     }
     
     public Iterator containers(String startWordHash, boolean up, boolean rot) throws IOException {
diff --git a/source/de/anomic/plasma/plasmaWordIndexFile.java b/source/de/anomic/plasma/plasmaWordIndexFile.java
index 2a706e118..928ac234e 100644
--- a/source/de/anomic/plasma/plasmaWordIndexFile.java
+++ b/source/de/anomic/plasma/plasmaWordIndexFile.java
@@ -85,23 +85,13 @@ public final class plasmaWordIndexFile {
 
     private kelondroTree indexFile(File databaseRoot, String wordHash) {
         if (wordHash.length() < 12) throw new RuntimeException("word hash wrong: '" + wordHash + "'");
-    theLocation = wordHash2path(databaseRoot, wordHash);
-    File fp = theLocation.getParentFile();
-    if (fp != null) fp.mkdirs();
-    kelondroTree kt;
-    long cacheSize = theLocation.length();
-    if (cacheSize > 1048576) cacheSize = 1048576;
-    if (theLocation.exists()) try {
-        // open existing index file
-        kt = new kelondroTree(theLocation, cacheSize, 0, kelondroTree.defaultObjectCachePercent);
-    } catch (IOException e) {
-        theLocation.delete();
-        kt = new kelondroTree(theLocation, cacheSize, 0, kelondroTree.defaultObjectCachePercent, new kelondroRow("byte[] urlhash-" + indexURL.urlHashLength + ", byte[] ba-" + indexURLEntry.encodedByteArrayFormLength(false)), false);
-    } else {
-        // create new index file
-        kt = new kelondroTree(theLocation, cacheSize, 0, kelondroTree.defaultObjectCachePercent, new kelondroRow("byte[] urlhash-" + indexURL.urlHashLength + ", byte[] ba-" + indexURLEntry.encodedByteArrayFormLength(false)), false);
-    }
-    return kt; // everyone who get this should close it when finished!
+        theLocation = wordHash2path(databaseRoot, wordHash);
+        File fp = theLocation.getParentFile();
+        if (fp != null) fp.mkdirs();
+        long cacheSize = theLocation.length();
+        if (cacheSize > 1048576) cacheSize = 1048576;
+        return kelondroTree.open(theLocation, cacheSize, 0, kelondroTree.defaultObjectCachePercent,
+                    new kelondroRow("byte[] urlhash-" + indexURL.urlHashLength + ", byte[] ba-" + indexURLEntry.encodedByteArrayFormLength(false)));
     }
 
     public static File wordHash2path(File databaseRoot, String hash) {
diff --git a/source/de/anomic/yacy/yacyNewsDB.java b/source/de/anomic/yacy/yacyNewsDB.java
index 9053bf555..f8c9e13a4 100644
--- a/source/de/anomic/yacy/yacyNewsDB.java
+++ b/source/de/anomic/yacy/yacyNewsDB.java
@@ -67,25 +67,13 @@ public class yacyNewsDB {
         this.path = path;
         this.bufferkb = bufferkb;
         this.preloadTime = preloadTime;
-        
-        if (path.exists()) try {
-            news = new kelondroTree(path, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent);
-            news.assignRowdef(yacyNewsRecord.rowdef);
-        } catch (IOException e) {
-            news = createDB(path, bufferkb, preloadTime);
-        } else {
-            news = createDB(path, bufferkb, preloadTime);
-        }
-    }
-
-    private static kelondroTree createDB(File path, int bufferkb, long preloadTime) {
-        return new kelondroTree(path, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, yacyNewsRecord.rowdef, true);
+        this.news = kelondroTree.open(path, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, yacyNewsRecord.rowdef);
     }
 
     private void resetDB() {
         try {close();} catch (Exception e) {}
         if (path.exists()) path.delete();
-        news = createDB(path, bufferkb, preloadTime);
+        this.news = kelondroTree.open(path, bufferkb * 0x400, preloadTime, kelondroTree.defaultObjectCachePercent, yacyNewsRecord.rowdef);
     }
 
     public int cacheNodeChunkSize() {
diff --git a/source/de/anomic/yacy/yacyNewsQueue.java b/source/de/anomic/yacy/yacyNewsQueue.java
index 31c7d58d6..b34a86d3d 100644
--- a/source/de/anomic/yacy/yacyNewsQueue.java
+++ b/source/de/anomic/yacy/yacyNewsQueue.java
@@ -51,44 +51,28 @@ import java.util.Date;
 import de.anomic.kelondro.kelondroColumn;
 import de.anomic.kelondro.kelondroRow;
 import de.anomic.kelondro.kelondroStack;
-import de.anomic.kelondro.kelondroException;
 
 public class yacyNewsQueue {
 
     private File path;
     private kelondroStack queueStack;
     private yacyNewsDB newsDB;
-
-    public yacyNewsQueue(File path, yacyNewsDB newsDB) {
-        this.path = path;
-        this.newsDB = newsDB;
-
-        if (path.exists()) try {
-            queueStack = new kelondroStack(path);
-        } catch (kelondroException e) {
-            path.delete();
-            queueStack = createStack(path);
-        } catch (IOException e) {
-            path.delete();
-            queueStack = createStack(path);
-        } else {
-            queueStack = createStack(path);
-        }
-    }
     
     public static final kelondroRow rowdef = new kelondroRow(new kelondroColumn[]{
             new kelondroColumn("newsid", kelondroColumn.celltype_string, kelondroColumn.encoder_bytes, yacyNewsRecord.idLength, "id = created + originator"),
             new kelondroColumn("last touched", kelondroColumn.celltype_string, kelondroColumn.encoder_bytes, yacyCore.universalDateShortPattern.length(), "")
     });
 
-    private static kelondroStack createStack(File path) {
-        return new kelondroStack(path, rowdef, true);
+    public yacyNewsQueue(File path, yacyNewsDB newsDB) {
+        this.path = path;
+        this.newsDB = newsDB;
+        this.queueStack = kelondroStack.open(path, rowdef);
     }
 
     private void resetDB() {
         try {close();} catch (Exception e) {}
         if (path.exists()) path.delete();
-        queueStack = createStack(path);
+        queueStack = kelondroStack.open(path, rowdef);
     }
 
     public void clear() {
diff --git a/source/de/anomic/yacy/yacySeedDB.java b/source/de/anomic/yacy/yacySeedDB.java
index d27f5629d..c3cacb67c 100644
--- a/source/de/anomic/yacy/yacySeedDB.java
+++ b/source/de/anomic/yacy/yacySeedDB.java
@@ -202,25 +202,14 @@ public final class yacySeedDB {
     }
     
     private synchronized kelondroMap openSeedTable(File seedDBFile) {
-        if (seedDBFile.exists()) try {
-            // open existing seed database
-            return new kelondroMap(new kelondroDyn(seedDBFile, (seedDBBufferKB * 0x400) / 3, preloadTime / 3, '#'), sortFields, accFields);
-        } catch (kelondroException e) {
-            // if we have an error, we start with a fresh database
-            if (seedDBFile.exists()) seedDBFile.delete();
-        } catch (IOException e) {
-            // if we have an error, we start with a fresh database
-            if (seedDBFile.exists()) seedDBFile.delete();
-        }
-        // create new seed database
-        new File(seedDBFile.getParent()).mkdir();
-        return new kelondroMap(new kelondroDyn(seedDBFile, (seedDBBufferKB * 0x400) / 3, preloadTime / 3, commonHashLength, 480, '#', true), sortFields, accFields);
+        new File(seedDBFile.getParent()).mkdirs();
+        return new kelondroMap(kelondroDyn.open(seedDBFile, (seedDBBufferKB * 0x400) / 3, preloadTime / 3, commonHashLength, 480, '#'), sortFields, accFields);
     }
     
     protected synchronized kelondroMap resetSeedTable(kelondroMap seedDB, File seedDBFile) {
         // this is an emergency function that should only be used if any problem with the
         // seed.db is detected
-    yacyCore.log.logFine("seed-db " + seedDBFile.toString() + " reset (on-the-fly)");
+        yacyCore.log.logFine("seed-db " + seedDBFile.toString() + " reset (on-the-fly)");
         try {
             seedDB.close();
             seedDBFile.delete();
diff --git a/source/yacy.java b/source/yacy.java
index eb8e5c747..4fb63694f 100644
--- a/source/yacy.java
+++ b/source/yacy.java
@@ -1223,7 +1223,7 @@ public final class yacy {
             String[] dbFileNames = {"seed.new.db","seed.old.db","seed.pot.db"};
             for (int i=0; i < dbFileNames.length; i++) {
                 File dbFile = new File(yacyDBPath,dbFileNames[i]);
-                kelondroMap db = new kelondroMap(new kelondroDyn(dbFile, (1024 * 0x400) / 3, 3000, '#'), yacySeedDB.sortFields, yacySeedDB.accFields);
+                kelondroMap db = new kelondroMap(new kelondroDyn(dbFile, (1024 * 0x400) / 3, 3000, yacySeedDB.commonHashLength, 480, '#'), yacySeedDB.sortFields, yacySeedDB.accFields);
                 
                 kelondroMap.mapIterator it;
                 it = db.maps(true, false);