[202833] Horizontal Mapping Strategy

https://bugs.eclipse.org/bugs/show_bug.cgi?id=202833

22 files changed, 343 insertions, 395 deletions

diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IAttributeMapping.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IAttributeMapping.java
index 9b7116918e..3e32ea2637 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IAttributeMapping.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IAttributeMapping.java
@@ -11,7 +11,6 @@
 package org.eclipse.emf.cdo.server.db;
 
 import org.eclipse.emf.cdo.internal.protocol.revision.CDORevisionImpl;
-import org.eclipse.emf.cdo.protocol.model.CDOFeature;
 
 import org.eclipse.net4j.db.IDBField;
 
@@ -20,12 +19,8 @@ import java.sql.ResultSet;
 /**
  * @author Eike Stepper
  */
-public interface IAttributeMapping
+public interface IAttributeMapping extends IFeatureMapping
 {
-  public IValueMapping getValueMapping();
-
-  public CDOFeature getFeature();
-
   public IDBField getField();
 
   public void appendValue(StringBuilder builder, CDORevisionImpl revision);
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IMapping.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IClassMapping.java
index 9d886ac459..741b43f92e 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IMapping.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IClassMapping.java
@@ -12,22 +12,32 @@ package org.eclipse.emf.cdo.server.db;
 
 import org.eclipse.emf.cdo.internal.protocol.revision.CDORevisionImpl;
 import org.eclipse.emf.cdo.protocol.model.CDOClass;
+import org.eclipse.emf.cdo.protocol.model.CDOFeature;
 
 import org.eclipse.net4j.db.IDBTable;
 
+import java.util.List;
 import java.util.Set;
 
 /**
  * @author Eike Stepper
  */
-public interface IMapping
+public interface IClassMapping
 {
   public IMappingStrategy getMappingStrategy();
 
   public CDOClass getCDOClass();
 
+  public IDBTable getTable();
+
   public Set<IDBTable> getAffectedTables();
 
+  public List<IAttributeMapping> getAttributeMappings();
+
+  public List<IReferenceMapping> getReferenceMappings();
+
+  public IReferenceMapping getReferenceMapping(CDOFeature feature);
+
   public void writeRevision(IDBStoreAccessor storeAccessor, CDORevisionImpl revision);
 
   public void readRevision(IDBStoreAccessor storeAccessor, CDORevisionImpl revision, int referenceChunk);
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IValueMapping.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IFeatureMapping.java
index 90f1a68e86..8b471ad3db 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IValueMapping.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IFeatureMapping.java
@@ -12,20 +12,12 @@ package org.eclipse.emf.cdo.server.db;
 
 import org.eclipse.emf.cdo.protocol.model.CDOFeature;
 
-import org.eclipse.net4j.db.IDBTable;
-
-import java.util.List;
-
 /**
  * @author Eike Stepper
  */
-public interface IValueMapping extends IMapping
+public interface IFeatureMapping
 {
-  public IDBTable getTable();
-
-  public List<IAttributeMapping> getAttributeMappings();
-
-  public List<IReferenceMapping> getReferenceMappings();
+  public IClassMapping getClassMapping();
 
-  public IReferenceMapping getReferenceMapping(CDOFeature feature);
+  public CDOFeature getFeature();
 }
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IMappingStrategy.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IMappingStrategy.java
index c7704798aa..9335dbe1a3 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IMappingStrategy.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IMappingStrategy.java
@@ -39,7 +39,7 @@ public interface IMappingStrategy
 
   public void setProperties(Map<String, String> properties);
 
-  public IMapping getMapping(CDOClass cdoClass);
+  public IClassMapping getClassMapping(CDOClass cdoClass);
 
   public CloseableIterator<CDOID> readObjectIDs(IDBStoreAccessor storeAccessor, boolean withTypes);
 
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IReferenceMapping.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IReferenceMapping.java
index 6d3aeca92a..376e42f499 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IReferenceMapping.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/db/IReferenceMapping.java
@@ -11,7 +11,6 @@
 package org.eclipse.emf.cdo.server.db;
 
 import org.eclipse.emf.cdo.internal.protocol.revision.CDORevisionImpl;
-import org.eclipse.emf.cdo.protocol.model.CDOFeature;
 import org.eclipse.emf.cdo.server.IStoreChunkReader.Chunk;
 
 import org.eclipse.net4j.db.IDBTable;
@@ -21,12 +20,8 @@ import java.util.List;
 /**
  * @author Eike Stepper
  */
-public interface IReferenceMapping
+public interface IReferenceMapping extends IFeatureMapping
 {
-  public IValueMapping getValueMapping();
-
-  public CDOFeature getFeature();
-
   public IDBTable getTable();
 
   public void writeReference(IDBStoreAccessor storeAccessor, CDORevisionImpl revision);
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/AttributeMapping.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/AttributeMapping.java
index 7331fef0a0..3d6811258b 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/AttributeMapping.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/AttributeMapping.java
@@ -20,10 +20,10 @@ public abstract class AttributeMapping extends FeatureMapping implements IAttrib
 {
   private IDBField field;
 
-  public AttributeMapping(ValueMapping valueMapping, CDOFeature feature)
+  public AttributeMapping(ClassMapping classMapping, CDOFeature feature)
   {
-    super(valueMapping, feature);
-    field = valueMapping.addField(feature, valueMapping.getTable());
+    super(classMapping, feature);
+    field = classMapping.addField(feature, classMapping.getTable());
   }
 
   public IDBField getField()
@@ -74,9 +74,9 @@ public abstract class AttributeMapping extends FeatureMapping implements IAttrib
    */
   public static class AMString extends AttributeMapping
   {
-    public AMString(ValueMapping valueMapping, CDOFeature feature)
+    public AMString(ClassMapping classMapping, CDOFeature feature)
     {
-      super(valueMapping, feature);
+      super(classMapping, feature);
     }
 
     @Override
@@ -91,9 +91,9 @@ public abstract class AttributeMapping extends FeatureMapping implements IAttrib
    */
   public static class AMShort extends AttributeMapping
   {
-    public AMShort(ValueMapping valueMapping, CDOFeature feature)
+    public AMShort(ClassMapping classMapping, CDOFeature feature)
     {
-      super(valueMapping, feature);
+      super(classMapping, feature);
     }
 
     @Override
@@ -108,9 +108,9 @@ public abstract class AttributeMapping extends FeatureMapping implements IAttrib
    */
   public static class AMObject extends AttributeMapping
   {
-    public AMObject(ValueMapping valueMapping, CDOFeature feature)
+    public AMObject(ClassMapping classMapping, CDOFeature feature)
     {
-      super(valueMapping, feature);
+      super(classMapping, feature);
     }
 
     @Override
@@ -131,9 +131,9 @@ public abstract class AttributeMapping extends FeatureMapping implements IAttrib
    */
   public static class AMLong extends AttributeMapping
   {
-    public AMLong(ValueMapping valueMapping, CDOFeature feature)
+    public AMLong(ClassMapping classMapping, CDOFeature feature)
     {
-      super(valueMapping, feature);
+      super(classMapping, feature);
     }
 
     @Override
@@ -148,9 +148,9 @@ public abstract class AttributeMapping extends FeatureMapping implements IAttrib
    */
   public static class AMInteger extends AttributeMapping
   {
-    public AMInteger(ValueMapping valueMapping, CDOFeature feature)
+    public AMInteger(ClassMapping classMapping, CDOFeature feature)
     {
-      super(valueMapping, feature);
+      super(classMapping, feature);
     }
 
     @Override
@@ -165,9 +165,9 @@ public abstract class AttributeMapping extends FeatureMapping implements IAttrib
    */
   public static class AMFloat extends AttributeMapping
   {
-    public AMFloat(ValueMapping valueMapping, CDOFeature feature)
+    public AMFloat(ClassMapping classMapping, CDOFeature feature)
     {
-      super(valueMapping, feature);
+      super(classMapping, feature);
     }
 
     @Override
@@ -182,9 +182,9 @@ public abstract class AttributeMapping extends FeatureMapping implements IAttrib
    */
   public static class AMDouble extends AttributeMapping
   {
-    public AMDouble(ValueMapping valueMapping, CDOFeature feature)
+    public AMDouble(ClassMapping classMapping, CDOFeature feature)
     {
-      super(valueMapping, feature);
+      super(classMapping, feature);
     }
 
     @Override
@@ -199,9 +199,9 @@ public abstract class AttributeMapping extends FeatureMapping implements IAttrib
    */
   public static class AMDate extends AttributeMapping
   {
-    public AMDate(ValueMapping valueMapping, CDOFeature feature)
+    public AMDate(ClassMapping classMapping, CDOFeature feature)
     {
-      super(valueMapping, feature);
+      super(classMapping, feature);
     }
 
     @Override
@@ -217,9 +217,9 @@ public abstract class AttributeMapping extends FeatureMapping implements IAttrib
    */
   public static class AMCharacter extends AttributeMapping
   {
-    public AMCharacter(ValueMapping valueMapping, CDOFeature feature)
+    public AMCharacter(ClassMapping classMapping, CDOFeature feature)
     {
-      super(valueMapping, feature);
+      super(classMapping, feature);
     }
 
     @Override
@@ -240,9 +240,9 @@ public abstract class AttributeMapping extends FeatureMapping implements IAttrib
    */
   public static class AMByte extends AttributeMapping
   {
-    public AMByte(ValueMapping valueMapping, CDOFeature feature)
+    public AMByte(ClassMapping classMapping, CDOFeature feature)
     {
-      super(valueMapping, feature);
+      super(classMapping, feature);
     }
 
     @Override
@@ -257,9 +257,9 @@ public abstract class AttributeMapping extends FeatureMapping implements IAttrib
    */
   public static class AMBoolean extends AttributeMapping
   {
-    public AMBoolean(ValueMapping valueMapping, CDOFeature feature)
+    public AMBoolean(ClassMapping classMapping, CDOFeature feature)
     {
-      super(valueMapping, feature);
+      super(classMapping, feature);
     }
 
     @Override
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ValueMapping.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ClassMapping.java
index 442904a61d..22f3a0b8a3 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ValueMapping.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ClassMapping.java
@@ -16,27 +16,43 @@ import org.eclipse.emf.cdo.protocol.model.CDOClass;
 import org.eclipse.emf.cdo.protocol.model.CDOFeature;
 import org.eclipse.emf.cdo.protocol.model.CDOType;
 import org.eclipse.emf.cdo.server.db.IAttributeMapping;
+import org.eclipse.emf.cdo.server.db.IClassMapping;
+import org.eclipse.emf.cdo.server.db.IDBStore;
 import org.eclipse.emf.cdo.server.db.IDBStoreAccessor;
 import org.eclipse.emf.cdo.server.db.IReferenceMapping;
-import org.eclipse.emf.cdo.server.db.IValueMapping;
 import org.eclipse.emf.cdo.server.internal.db.bundle.OM;
 
 import org.eclipse.net4j.db.DBException;
+import org.eclipse.net4j.db.DBType;
 import org.eclipse.net4j.db.DBUtil;
+import org.eclipse.net4j.db.IDBAdapter;
+import org.eclipse.net4j.db.IDBField;
+import org.eclipse.net4j.db.IDBTable;
 import org.eclipse.net4j.internal.util.om.trace.ContextTracer;
 import org.eclipse.net4j.util.ImplementationError;
 
 import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.sql.Statement;
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 /**
  * @author Eike Stepper
  */
-public abstract class ValueMapping extends Mapping implements IValueMapping
+public abstract class ClassMapping implements IClassMapping
 {
-  private static final ContextTracer TRACER = new ContextTracer(OM.DEBUG, ValueMapping.class);
+  private static final ContextTracer TRACER = new ContextTracer(OM.DEBUG, ClassMapping.class);
+
+  private MappingStrategy mappingStrategy;
+
+  private CDOClass cdoClass;
+
+  private IDBTable table;
+
+  private Set<IDBTable> affectedTables = new HashSet<IDBTable>();
 
   private List<IAttributeMapping> attributeMappings;
 
@@ -46,17 +62,165 @@ public abstract class ValueMapping extends Mapping implements IValueMapping
 
   private String selectPrefixWithVersion;
 
-  public ValueMapping(MappingStrategy mappingStrategy, CDOClass cdoClass, CDOFeature[] features)
+  public ClassMapping(MappingStrategy mappingStrategy, CDOClass cdoClass, CDOFeature[] features)
   {
-    super(mappingStrategy, cdoClass);
-    initTable(getTable(), hasFullRevisionInfo());
-    attributeMappings = createAttributeMappings(features);
-    referenceMappings = createReferenceMappings(features);
+    this.mappingStrategy = mappingStrategy;
+    this.cdoClass = cdoClass;
+
+    table = addTable(cdoClass.getName());
+    initTable(table, hasFullRevisionInfo());
+
+    if (features != null)
+    {
+      attributeMappings = createAttributeMappings(features);
+      referenceMappings = createReferenceMappings(features);
+    }
 
     selectPrefix = createSelectPrefix(false);
     selectPrefixWithVersion = createSelectPrefix(true);
   }
 
+  public MappingStrategy getMappingStrategy()
+  {
+    return mappingStrategy;
+  }
+
+  public CDOClass getCDOClass()
+  {
+    return cdoClass;
+  }
+
+  public IDBTable getTable()
+  {
+    return table;
+  }
+
+  public Set<IDBTable> getAffectedTables()
+  {
+    return affectedTables;
+  }
+
+  protected void initTable(IDBTable table, boolean full)
+  {
+    table.addField(CDODBSchema.ATTRIBUTES_ID, DBType.BIGINT);
+    table.addField(CDODBSchema.ATTRIBUTES_VERSION, DBType.INTEGER);
+    if (full)
+    {
+      table.addField(CDODBSchema.ATTRIBUTES_CLASS, DBType.INTEGER);
+      table.addField(CDODBSchema.ATTRIBUTES_CREATED, DBType.BIGINT);
+      table.addField(CDODBSchema.ATTRIBUTES_REVISED, DBType.BIGINT);
+      table.addField(CDODBSchema.ATTRIBUTES_RESOURCE, DBType.BIGINT);
+      table.addField(CDODBSchema.ATTRIBUTES_CONTAINER, DBType.BIGINT);
+      table.addField(CDODBSchema.ATTRIBUTES_FEATURE, DBType.INTEGER);
+    }
+  }
+
+  protected void appendRevisionInfos(StringBuilder builder, CDORevisionImpl revision, boolean full)
+  {
+    builder.append(revision.getID().getValue());
+    builder.append(", ");
+    builder.append(revision.getVersion());
+    if (full)
+    {
+      builder.append(", ");
+      builder.append(ServerInfo.getDBID(revision.getCDOClass()));
+      builder.append(", ");
+      builder.append(revision.getCreated());
+      builder.append(", ");
+      builder.append(revision.getRevised());
+      builder.append(", ");
+      builder.append(revision.getResourceID().getValue());
+      builder.append(", ");
+      builder.append(revision.getContainerID().getValue());
+      builder.append(", ");
+      builder.append(revision.getContainingFeatureID());
+    }
+  }
+
+  protected int sqlUpdate(IDBStoreAccessor storeAccessor, String sql) throws DBException
+  {
+    if (TRACER.isEnabled())
+    {
+      TRACER.trace(sql);
+    }
+
+    try
+    {
+      Statement statement = storeAccessor.getStatement();
+      return statement.executeUpdate(sql);
+    }
+    catch (SQLException ex)
+    {
+      throw new DBException(ex);
+    }
+  }
+
+  protected String mangleTableName(String name, int attempt)
+  {
+    return getDBAdapter().mangleTableName(name, attempt);
+  }
+
+  protected String mangleFieldName(String name, int attempt)
+  {
+    return getDBAdapter().mangleFieldName(name, attempt);
+  }
+
+  protected IDBTable addTable(String name)
+  {
+    for (int attempt = 0;; ++attempt)
+    {
+      String tableName = mangleTableName(name, attempt);
+
+      try
+      {
+        IDBTable table = mappingStrategy.getStore().getSchema().addTable(tableName);
+        affectedTables.add(table);
+        return table;
+      }
+      catch (DBException ex)
+      {
+        if (TRACER.isEnabled())
+        {
+          TRACER.format("{0}. attempt to add table: {1} ({2})", attempt + 1, tableName, ex.getMessage());
+        }
+      }
+    }
+  }
+
+  protected IDBField addField(CDOFeature cdoFeature, IDBTable table) throws DBException
+  {
+    DBType fieldType = getDBType(cdoFeature.getType());
+    for (int attempt = 0;; ++attempt)
+    {
+      String fieldName = mangleFieldName(cdoFeature.getName(), attempt);
+
+      try
+      {
+        IDBField field = table.addField(fieldName, fieldType);
+        affectedTables.add(table);
+        return field;
+      }
+      catch (DBException ex)
+      {
+        if (TRACER.isEnabled())
+        {
+          TRACER.format("{0}. attempt to add field: {1} ({2})", attempt + 1, fieldName, ex.getMessage());
+        }
+      }
+    }
+  }
+
+  protected DBType getDBType(CDOType type)
+  {
+    return DBStore.getDBType(type);
+  }
+
+  protected IDBAdapter getDBAdapter()
+  {
+    IDBStore store = mappingStrategy.getStore();
+    return store.getDBAdapter();
+  }
+
   protected String createSelectPrefix(boolean readVersion)
   {
     StringBuilder builder = new StringBuilder();
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ClassServerInfo.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ClassServerInfo.java
index 5693ffb71a..cbb44c219d 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ClassServerInfo.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ClassServerInfo.java
@@ -11,7 +11,7 @@
 package org.eclipse.emf.cdo.server.internal.db;
 
 import org.eclipse.emf.cdo.protocol.model.CDOClass;
-import org.eclipse.emf.cdo.server.db.IMapping;
+import org.eclipse.emf.cdo.server.db.IClassMapping;
 
 import org.eclipse.net4j.util.ImplementationError;
 
@@ -24,7 +24,7 @@ public final class ClassServerInfo extends ServerInfo
 
   public static final int CDO_RESOURCE_CLASS_DBID = -2;
 
-  private IMapping mapping;
+  private IClassMapping classMapping;
 
   private ClassServerInfo(int id)
   {
@@ -38,13 +38,13 @@ public final class ClassServerInfo extends ServerInfo
     return serverInfo;
   }
 
-  public static IMapping getMapping(CDOClass cdoClass)
+  public static IClassMapping getClassMapping(CDOClass cdoClass)
   {
     ClassServerInfo serverInfo = getServerInfo(cdoClass);
-    return serverInfo == null ? null : serverInfo.mapping;
+    return serverInfo == null ? null : serverInfo.classMapping;
   }
 
-  public static void setMapping(CDOClass cdoClass, IMapping mapping)
+  public static void setClassMapping(CDOClass cdoClass, IClassMapping classMapping)
   {
     ClassServerInfo serverInfo = getServerInfo(cdoClass);
     if (serverInfo == null)
@@ -52,7 +52,7 @@ public final class ClassServerInfo extends ServerInfo
       throw new ImplementationError("No serverInfo for class " + cdoClass);
     }
 
-    serverInfo.mapping = mapping;
+    serverInfo.classMapping = classMapping;
   }
 
   protected static ClassServerInfo getServerInfo(CDOClass cdoClass)
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/DBStoreAccessor.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/DBStoreAccessor.java
index f903571ef1..3701df0af8 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/DBStoreAccessor.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/DBStoreAccessor.java
@@ -32,7 +32,7 @@ import org.eclipse.emf.cdo.server.ISession;
 import org.eclipse.emf.cdo.server.IStoreChunkReader;
 import org.eclipse.emf.cdo.server.IView;
 import org.eclipse.emf.cdo.server.db.IDBStoreAccessor;
-import org.eclipse.emf.cdo.server.db.IMapping;
+import org.eclipse.emf.cdo.server.db.IClassMapping;
 import org.eclipse.emf.cdo.server.db.IMappingStrategy;
 import org.eclipse.emf.cdo.server.internal.db.bundle.OM;
 
@@ -394,7 +394,7 @@ public class DBStoreAccessor implements IDBStoreAccessor
     }
 
     CDOClassImpl cdoClass = revision.getCDOClass();
-    IMapping mapping = ClassServerInfo.getMapping(cdoClass);
+    IClassMapping mapping = ClassServerInfo.getClassMapping(cdoClass);
     mapping.writeRevision(this, revision);
   }
 
@@ -429,7 +429,7 @@ public class DBStoreAccessor implements IDBStoreAccessor
     CDOClassImpl cdoClass = getObjectType(id);
     CDORevisionImpl revision = new CDORevisionImpl(revisionManager, cdoClass, id);
 
-    IMapping mapping = ClassServerInfo.getMapping(cdoClass);
+    IClassMapping mapping = ClassServerInfo.getClassMapping(cdoClass);
     mapping.readRevision(this, revision, referenceChunk);
     return revision;
   }
@@ -445,7 +445,7 @@ public class DBStoreAccessor implements IDBStoreAccessor
     CDOClassImpl cdoClass = getObjectType(id);
     CDORevisionImpl revision = new CDORevisionImpl(revisionManager, cdoClass, id);
 
-    IMapping mapping = ClassServerInfo.getMapping(cdoClass);
+    IClassMapping mapping = ClassServerInfo.getClassMapping(cdoClass);
     mapping.readRevisionByTime(this, revision, timeStamp, referenceChunk);
     return revision;
   }
@@ -461,13 +461,14 @@ public class DBStoreAccessor implements IDBStoreAccessor
     CDOClassImpl cdoClass = getObjectType(id);
     CDORevisionImpl revision = new CDORevisionImpl(revisionManager, cdoClass, id);
 
-    IMapping mapping = ClassServerInfo.getMapping(cdoClass);
+    IClassMapping mapping = ClassServerInfo.getClassMapping(cdoClass);
     mapping.readRevisionByVersion(this, revision, version, referenceChunk);
     return revision;
   }
 
   public CDOID readResourceID(String path)
   {
+    IMappingStrategy mappingStrategy = getStore().getMappingStrategy();
     // TODO Implement method DBStoreAccessor.readResourceID()
     throw new UnsupportedOperationException("Not yet implemented");
   }
@@ -537,7 +538,7 @@ public class DBStoreAccessor implements IDBStoreAccessor
       IMappingStrategy mappingStrategy = store.getMappingStrategy();
       for (CDOClassImpl cdoClass : cdoClasses)
       {
-        IMapping mapping = mappingStrategy.getMapping(cdoClass);
+        IClassMapping mapping = mappingStrategy.getClassMapping(cdoClass);
         if (mapping != null)
         {
           affectedTables.addAll(mapping.getAffectedTables());
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/DBStoreChunkReader.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/DBStoreChunkReader.java
index 610a9c4f12..6c99db4075 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/DBStoreChunkReader.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/DBStoreChunkReader.java
@@ -14,14 +14,12 @@ import org.eclipse.emf.cdo.internal.server.StoreChunkReader;
 import org.eclipse.emf.cdo.protocol.model.CDOClass;
 import org.eclipse.emf.cdo.protocol.model.CDOFeature;
 import org.eclipse.emf.cdo.protocol.revision.CDORevision;
+import org.eclipse.emf.cdo.server.db.IClassMapping;
 import org.eclipse.emf.cdo.server.db.IDBStoreAccessor;
 import org.eclipse.emf.cdo.server.db.IDBStoreChunkReader;
-import org.eclipse.emf.cdo.server.db.IMapping;
 import org.eclipse.emf.cdo.server.db.IMappingStrategy;
 import org.eclipse.emf.cdo.server.db.IReferenceMapping;
 
-import org.eclipse.net4j.util.ImplementationError;
-
 import java.util.List;
 
 /**
@@ -37,16 +35,8 @@ public class DBStoreChunkReader extends StoreChunkReader implements IDBStoreChun
   {
     super(storeAccessor, revision, feature);
     IMappingStrategy mappingStrategy = storeAccessor.getStore().getMappingStrategy();
-    CDOClass cdoClass = revision.getCDOClass();
-    IMapping mapping = mappingStrategy.getMapping(cdoClass);
-    if (mapping instanceof ValueMapping)
-    {
-      referenceMapping = ((ValueMapping)mapping).getReferenceMapping(feature);
-    }
-    else
-    {
-      throw new ImplementationError();
-    }
+    IClassMapping mapping = mappingStrategy.getClassMapping(revision.getCDOClass());
+    referenceMapping = mapping.getReferenceMapping(feature);
   }
 
   @Override
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/FeatureMapping.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/FeatureMapping.java
index 676a390b6e..cd595f89ba 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/FeatureMapping.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/FeatureMapping.java
@@ -19,19 +19,19 @@ import org.eclipse.net4j.db.IDBAdapter;
  */
 public class FeatureMapping
 {
-  private ValueMapping valueMapping;
+  private ClassMapping classMapping;
 
   private CDOFeature feature;
 
-  public FeatureMapping(ValueMapping valueMapping, CDOFeature feature)
+  public FeatureMapping(ClassMapping classMapping, CDOFeature feature)
   {
-    this.valueMapping = valueMapping;
+    this.classMapping = classMapping;
     this.feature = feature;
   }
 
-  public ValueMapping getValueMapping()
+  public ClassMapping getClassMapping()
   {
-    return valueMapping;
+    return classMapping;
   }
 
   public CDOFeature getFeature()
@@ -41,6 +41,6 @@ public class FeatureMapping
 
   protected IDBAdapter getDBAdapter()
   {
-    return getValueMapping().getMappingStrategy().getStore().getDBAdapter();
+    return getClassMapping().getMappingStrategy().getStore().getDBAdapter();
   }
 }
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/HorizontalMapping.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/HorizontalClassMapping.java
index 7e75541c7f..9734475716 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/HorizontalMapping.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/HorizontalClassMapping.java
@@ -15,9 +15,9 @@ import org.eclipse.emf.cdo.protocol.model.CDOClass;
 /**
  * @author Eike Stepper
  */
-public class HorizontalMapping extends ValueMapping
+public class HorizontalClassMapping extends ClassMapping
 {
-  public HorizontalMapping(HorizontalMappingStrategy mappingStrategy, CDOClass cdoClass)
+  public HorizontalClassMapping(HorizontalMappingStrategy mappingStrategy, CDOClass cdoClass)
   {
     super(mappingStrategy, cdoClass, cdoClass.getAllFeatures());
   }
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/HorizontalMappingStrategy.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/HorizontalMappingStrategy.java
index b4174969b2..376514d778 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/HorizontalMappingStrategy.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/HorizontalMappingStrategy.java
@@ -13,7 +13,7 @@ package org.eclipse.emf.cdo.server.internal.db;
 import org.eclipse.emf.cdo.protocol.model.CDOClass;
 import org.eclipse.emf.cdo.protocol.model.CDOPackage;
 import org.eclipse.emf.cdo.server.IPackageManager;
-import org.eclipse.emf.cdo.server.db.IMapping;
+import org.eclipse.emf.cdo.server.db.IClassMapping;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -38,14 +38,14 @@ public class HorizontalMappingStrategy extends MappingStrategy
   }
 
   @Override
-  protected IMapping createMapping(CDOClass cdoClass)
+  protected IClassMapping createClassMapping(CDOClass cdoClass)
   {
     if (cdoClass.isAbstract())
     {
       return null;
     }
 
-    return new HorizontalMapping(this, cdoClass);
+    return new HorizontalClassMapping(this, cdoClass);
   }
 
   @Override
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/Mapping.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/Mapping.java
deleted file mode 100644
index 1cae9ad4fd..0000000000
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/Mapping.java
+++ /dev/null
@@ -1,196 +0,0 @@
-/***************************************************************************
- * Copyright (c) 2004 - 2007 Eike Stepper, Germany.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Eclipse Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/epl-v10.html
- * 
- * Contributors:
- *    Eike Stepper - initial API and implementation
- **************************************************************************/
-package org.eclipse.emf.cdo.server.internal.db;
-
-import org.eclipse.emf.cdo.internal.protocol.revision.CDORevisionImpl;
-import org.eclipse.emf.cdo.protocol.model.CDOClass;
-import org.eclipse.emf.cdo.protocol.model.CDOFeature;
-import org.eclipse.emf.cdo.protocol.model.CDOType;
-import org.eclipse.emf.cdo.server.db.IDBStore;
-import org.eclipse.emf.cdo.server.db.IDBStoreAccessor;
-import org.eclipse.emf.cdo.server.db.IMapping;
-import org.eclipse.emf.cdo.server.internal.db.bundle.OM;
-
-import org.eclipse.net4j.db.DBException;
-import org.eclipse.net4j.db.DBType;
-import org.eclipse.net4j.db.IDBAdapter;
-import org.eclipse.net4j.db.IDBField;
-import org.eclipse.net4j.db.IDBTable;
-import org.eclipse.net4j.internal.util.om.trace.ContextTracer;
-
-import java.sql.SQLException;
-import java.sql.Statement;
-import java.util.HashSet;
-import java.util.Set;
-
-/**
- * @author Eike Stepper
- */
-public abstract class Mapping implements IMapping
-{
-  private static final ContextTracer TRACER = new ContextTracer(OM.DEBUG, Mapping.class);
-
-  private MappingStrategy mappingStrategy;
-
-  private CDOClass cdoClass;
-
-  private IDBTable table;
-
-  private Set<IDBTable> affectedTables = new HashSet<IDBTable>();
-
-  public Mapping(MappingStrategy mappingStrategy, CDOClass cdoClass)
-  {
-    this.mappingStrategy = mappingStrategy;
-    this.cdoClass = cdoClass;
-    table = addTable(cdoClass.getName());
-  }
-
-  public MappingStrategy getMappingStrategy()
-  {
-    return mappingStrategy;
-  }
-
-  public CDOClass getCDOClass()
-  {
-    return cdoClass;
-  }
-
-  public IDBTable getTable()
-  {
-    return table;
-  }
-
-  public Set<IDBTable> getAffectedTables()
-  {
-    return affectedTables;
-  }
-
-  protected void initTable(IDBTable table, boolean full)
-  {
-    table.addField(CDODBSchema.ATTRIBUTES_ID, DBType.BIGINT);
-    table.addField(CDODBSchema.ATTRIBUTES_VERSION, DBType.INTEGER);
-    if (full)
-    {
-      table.addField(CDODBSchema.ATTRIBUTES_CLASS, DBType.INTEGER);
-      table.addField(CDODBSchema.ATTRIBUTES_CREATED, DBType.BIGINT);
-      table.addField(CDODBSchema.ATTRIBUTES_REVISED, DBType.BIGINT);
-      table.addField(CDODBSchema.ATTRIBUTES_RESOURCE, DBType.BIGINT);
-      table.addField(CDODBSchema.ATTRIBUTES_CONTAINER, DBType.BIGINT);
-      table.addField(CDODBSchema.ATTRIBUTES_FEATURE, DBType.INTEGER);
-    }
-  }
-
-  protected void appendRevisionInfos(StringBuilder builder, CDORevisionImpl revision, boolean full)
-  {
-    builder.append(revision.getID().getValue());
-    builder.append(", ");
-    builder.append(revision.getVersion());
-    if (full)
-    {
-      builder.append(", ");
-      builder.append(ServerInfo.getDBID(revision.getCDOClass()));
-      builder.append(", ");
-      builder.append(revision.getCreated());
-      builder.append(", ");
-      builder.append(revision.getRevised());
-      builder.append(", ");
-      builder.append(revision.getResourceID().getValue());
-      builder.append(", ");
-      builder.append(revision.getContainerID().getValue());
-      builder.append(", ");
-      builder.append(revision.getContainingFeatureID());
-    }
-  }
-
-  protected int sqlUpdate(IDBStoreAccessor storeAccessor, String sql) throws DBException
-  {
-    if (TRACER.isEnabled())
-    {
-      TRACER.trace(sql);
-    }
-
-    try
-    {
-      Statement statement = storeAccessor.getStatement();
-      return statement.executeUpdate(sql);
-    }
-    catch (SQLException ex)
-    {
-      throw new DBException(ex);
-    }
-  }
-
-  protected String mangleTableName(String name, int attempt)
-  {
-    return getDBAdapter().mangleTableName(name, attempt);
-  }
-
-  protected String mangleFieldName(String name, int attempt)
-  {
-    return getDBAdapter().mangleFieldName(name, attempt);
-  }
-
-  protected IDBTable addTable(String name)
-  {
-    for (int attempt = 0;; ++attempt)
-    {
-      String tableName = mangleTableName(name, attempt);
-
-      try
-      {
-        IDBTable table = mappingStrategy.getStore().getSchema().addTable(tableName);
-        affectedTables.add(table);
-        return table;
-      }
-      catch (DBException ex)
-      {
-        if (TRACER.isEnabled())
-        {
-          TRACER.format("{0}. attempt to add table: {1} ({2})", attempt + 1, tableName, ex.getMessage());
-        }
-      }
-    }
-  }
-
-  protected IDBField addField(CDOFeature cdoFeature, IDBTable table) throws DBException
-  {
-    DBType fieldType = getDBType(cdoFeature.getType());
-    for (int attempt = 0;; ++attempt)
-    {
-      String fieldName = mangleFieldName(cdoFeature.getName(), attempt);
-
-      try
-      {
-        IDBField field = table.addField(fieldName, fieldType);
-        affectedTables.add(table);
-        return field;
-      }
-      catch (DBException ex)
-      {
-        if (TRACER.isEnabled())
-        {
-          TRACER.format("{0}. attempt to add field: {1} ({2})", attempt + 1, fieldName, ex.getMessage());
-        }
-      }
-    }
-  }
-
-  protected DBType getDBType(CDOType type)
-  {
-    return DBStore.getDBType(type);
-  }
-
-  protected IDBAdapter getDBAdapter()
-  {
-    IDBStore store = mappingStrategy.getStore();
-    return store.getDBAdapter();
-  }
-}
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/MappingStrategy.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/MappingStrategy.java
index c4f6c81f02..8d6d235dde 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/MappingStrategy.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/MappingStrategy.java
@@ -15,7 +15,7 @@ import org.eclipse.emf.cdo.protocol.model.CDOClass;
 import org.eclipse.emf.cdo.protocol.model.CDOClassRef;
 import org.eclipse.emf.cdo.server.db.IDBStore;
 import org.eclipse.emf.cdo.server.db.IDBStoreAccessor;
-import org.eclipse.emf.cdo.server.db.IMapping;
+import org.eclipse.emf.cdo.server.db.IClassMapping;
 import org.eclipse.emf.cdo.server.db.IMappingStrategy;
 
 import org.eclipse.net4j.db.DBException;
@@ -122,18 +122,18 @@ public abstract class MappingStrategy implements IMappingStrategy
     return referenceTables;
   }
 
-  public IMapping getMapping(CDOClass cdoClass)
+  public IClassMapping getClassMapping(CDOClass cdoClass)
   {
-    IMapping mapping = ClassServerInfo.getMapping(cdoClass);
-    if (mapping == NoMapping.INSTANCE)
+    IClassMapping mapping = ClassServerInfo.getClassMapping(cdoClass);
+    if (mapping == NoClassMapping.INSTANCE)
     {
       return null;
     }
 
     if (mapping == null)
     {
-      mapping = createMapping(cdoClass);
-      ClassServerInfo.setMapping(cdoClass, mapping == null ? NoMapping.INSTANCE : mapping);
+      mapping = createClassMapping(cdoClass);
+      ClassServerInfo.setClassMapping(cdoClass, mapping == null ? NoClassMapping.INSTANCE : mapping);
     }
 
     return mapping;
@@ -151,7 +151,7 @@ public abstract class MappingStrategy implements IMappingStrategy
         while (classIt.hasNext())
         {
           CDOClass cdoClass = classIt.next();
-          ValueMapping mapping = (ValueMapping)ClassServerInfo.getMapping(cdoClass);
+          ClassMapping mapping = (ClassMapping)ClassServerInfo.getClassMapping(cdoClass);
           if (mapping != null)
           {
             IDBTable table = mapping.getTable();
@@ -193,7 +193,7 @@ public abstract class MappingStrategy implements IMappingStrategy
     String suffix = " WHERE " + CDODBSchema.ATTRIBUTES_ID + "=" + id;
     for (CDOClass cdoClass : getClassesWithObjectInfo())
     {
-      ValueMapping mapping = (ValueMapping)ClassServerInfo.getMapping(cdoClass);
+      ClassMapping mapping = (ClassMapping)ClassServerInfo.getClassMapping(cdoClass);
       if (mapping != null)
       {
         IDBTable table = mapping.getTable();
@@ -244,7 +244,7 @@ public abstract class MappingStrategy implements IMappingStrategy
     return getType();
   }
 
-  protected abstract IMapping createMapping(CDOClass cdoClass);
+  protected abstract IClassMapping createClassMapping(CDOClass cdoClass);
 
   protected abstract List<CDOClass> getClassesWithObjectInfo();
 }
\ No newline at end of file
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/NoMapping.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/NoClassMapping.java
index 51b22f5136..9a5d0230af 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/NoMapping.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/NoClassMapping.java
@@ -12,23 +12,27 @@ package org.eclipse.emf.cdo.server.internal.db;
 
 import org.eclipse.emf.cdo.internal.protocol.revision.CDORevisionImpl;
 import org.eclipse.emf.cdo.protocol.model.CDOClass;
+import org.eclipse.emf.cdo.protocol.model.CDOFeature;
+import org.eclipse.emf.cdo.server.db.IAttributeMapping;
 import org.eclipse.emf.cdo.server.db.IDBStoreAccessor;
-import org.eclipse.emf.cdo.server.db.IMapping;
+import org.eclipse.emf.cdo.server.db.IClassMapping;
 import org.eclipse.emf.cdo.server.db.IMappingStrategy;
+import org.eclipse.emf.cdo.server.db.IReferenceMapping;
 
 import org.eclipse.net4j.db.IDBTable;
 
 import java.util.Collections;
+import java.util.List;
 import java.util.Set;
 
 /**
  * @author Eike Stepper
  */
-public class NoMapping implements IMapping
+public class NoClassMapping implements IClassMapping
 {
-  public static final IMapping INSTANCE = new NoMapping();
+  public static final IClassMapping INSTANCE = new NoClassMapping();
 
-  private NoMapping()
+  private NoClassMapping()
   {
   }
 
@@ -42,11 +46,31 @@ public class NoMapping implements IMapping
     return null;
   }
 
+  public IDBTable getTable()
+  {
+    return null;
+  }
+
   public Set<IDBTable> getAffectedTables()
   {
     return Collections.emptySet();
   }
 
+  public List<IAttributeMapping> getAttributeMappings()
+  {
+    return null;
+  }
+
+  public IReferenceMapping getReferenceMapping(CDOFeature feature)
+  {
+    return null;
+  }
+
+  public List<IReferenceMapping> getReferenceMappings()
+  {
+    return null;
+  }
+
   public void writeRevision(IDBStoreAccessor storeAccessor, CDORevisionImpl revision)
   {
   }
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ReferenceMapping.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ReferenceMapping.java
index b9b5e7c01c..00696bb78c 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ReferenceMapping.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ReferenceMapping.java
@@ -44,11 +44,11 @@ public class ReferenceMapping extends FeatureMapping implements IReferenceMappin
 
   private String selectPrefix;
 
-  public ReferenceMapping(ValueMapping valueMapping, CDOFeature feature, ToMany toMany)
+  public ReferenceMapping(ClassMapping classMapping, CDOFeature feature, ToMany toMany)
   {
-    super(valueMapping, feature);
+    super(classMapping, feature);
     this.toMany = toMany;
-    mapReference(valueMapping.getCDOClass(), feature);
+    mapReference(classMapping.getCDOClass(), feature);
 
     int dbFeatureID = withFeature ? FeatureServerInfo.getDBID(getFeature()) : 0;
     insertPrefix = createInsertPrefix(dbFeatureID);
@@ -79,7 +79,7 @@ public class ReferenceMapping extends FeatureMapping implements IReferenceMappin
       builder.append(target);
       builder.append(")");
       String sql = builder.toString();
-      getValueMapping().sqlUpdate(storeAccessor, sql);
+      getClassMapping().sqlUpdate(storeAccessor, sql);
     }
   }
 
@@ -237,7 +237,7 @@ public class ReferenceMapping extends FeatureMapping implements IReferenceMappin
 
     case PER_REPOSITORY:
       withFeature = true;
-      IRepository repository = getValueMapping().getMappingStrategy().getStore().getRepository();
+      IRepository repository = getClassMapping().getMappingStrategy().getStore().getRepository();
       table = mapReferenceTable(repository, repository.getName() + "_refs");
       break;
 
@@ -248,7 +248,7 @@ public class ReferenceMapping extends FeatureMapping implements IReferenceMappin
 
   protected IDBTable mapReferenceTable(Object key, String tableName)
   {
-    Map<Object, IDBTable> referenceTables = getValueMapping().getMappingStrategy().getReferenceTables();
+    Map<Object, IDBTable> referenceTables = getClassMapping().getMappingStrategy().getReferenceTables();
     IDBTable table = referenceTables.get(key);
     if (table == null)
     {
@@ -261,7 +261,7 @@ public class ReferenceMapping extends FeatureMapping implements IReferenceMappin
 
   protected IDBTable addReferenceTable(String tableName)
   {
-    IDBTable table = getValueMapping().addTable(tableName);
+    IDBTable table = getClassMapping().addTable(tableName);
     if (withFeature)
     {
       table.addField(CDODBSchema.REFERENCES_FEATURE, DBType.INTEGER);
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/RootClassMapping.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/RootClassMapping.java
new file mode 100644
index 0000000000..3c09de2824
--- /dev/null
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/RootClassMapping.java
@@ -0,0 +1,42 @@
+/***************************************************************************
+ * Copyright (c) 2004 - 2007 Eike Stepper, Germany.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * Contributors:
+ *    Eike Stepper - initial API and implementation
+ **************************************************************************/
+package org.eclipse.emf.cdo.server.internal.db;
+
+import org.eclipse.emf.cdo.protocol.model.core.CDOObjectClass;
+
+/**
+ * @author Eike Stepper
+ */
+public class RootClassMapping extends ClassMapping
+{
+  public RootClassMapping(VerticalMappingStrategy mappingStrategy)
+  {
+    super(mappingStrategy, getRootClass(mappingStrategy), null);
+    initTable(getTable(), true);
+  }
+
+  @Override
+  public VerticalMappingStrategy getMappingStrategy()
+  {
+    return (VerticalMappingStrategy)super.getMappingStrategy();
+  }
+
+  @Override
+  protected boolean hasFullRevisionInfo()
+  {
+    return true;
+  }
+
+  private static CDOObjectClass getRootClass(VerticalMappingStrategy mappingStrategy)
+  {
+    return mappingStrategy.getStore().getRepository().getPackageManager().getCDOCorePackage().getCDOObjectClass();
+  }
+}
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/RootMapping.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/RootMapping.java
deleted file mode 100644
index 7714b2ce6f..0000000000
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/RootMapping.java
+++ /dev/null
@@ -1,69 +0,0 @@
-/***************************************************************************
- * Copyright (c) 2004 - 2007 Eike Stepper, Germany.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Eclipse Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/epl-v10.html
- * 
- * Contributors:
- *    Eike Stepper - initial API and implementation
- **************************************************************************/
-package org.eclipse.emf.cdo.server.internal.db;
-
-import org.eclipse.emf.cdo.internal.protocol.revision.CDORevisionImpl;
-import org.eclipse.emf.cdo.protocol.model.core.CDOObjectClass;
-import org.eclipse.emf.cdo.server.db.IDBStoreAccessor;
-
-/**
- * @author Eike Stepper
- */
-public class RootMapping extends Mapping
-{
-  public RootMapping(VerticalMappingStrategy mappingStrategy)
-  {
-    super(mappingStrategy, getRootClass(mappingStrategy));
-    initTable(getTable(), true);
-  }
-
-  @Override
-  public VerticalMappingStrategy getMappingStrategy()
-  {
-    return (VerticalMappingStrategy)super.getMappingStrategy();
-  }
-
-  public void writeRevision(IDBStoreAccessor storeAccessor, CDORevisionImpl revision)
-  {
-    StringBuilder builder = new StringBuilder();
-    builder.append("INSERT INTO ");
-    builder.append(getTable());
-    builder.append(" VALUES (");
-    appendRevisionInfos(builder, revision, true);
-    builder.append(")");
-    sqlUpdate(storeAccessor, builder.toString());
-  }
-
-  public void readRevision(IDBStoreAccessor storeAccessor, CDORevisionImpl revision, int referenceChunk)
-  {
-    // TODO Implement method RootMapping.readRevision()
-    throw new UnsupportedOperationException("Not yet implemented");
-  }
-
-  public void readRevisionByTime(IDBStoreAccessor storeAccessor, CDORevisionImpl revision, long timeStamp,
-      int referenceChunk)
-  {
-    // TODO Implement method RootMapping.readRevisionByTime()
-    throw new UnsupportedOperationException("Not yet implemented");
-  }
-
-  public void readRevisionByVersion(IDBStoreAccessor storeAccessor, CDORevisionImpl revision, int version,
-      int referenceChunk)
-  {
-    // TODO Implement method RootMapping.readRevisionByVersion()
-    throw new UnsupportedOperationException("Not yet implemented");
-  }
-
-  private static CDOObjectClass getRootClass(VerticalMappingStrategy mappingStrategy)
-  {
-    return mappingStrategy.getStore().getRepository().getPackageManager().getCDOCorePackage().getCDOObjectClass();
-  }
-}
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ToOneReferenceMapping.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ToOneReferenceMapping.java
index f8be13cae6..0a850b1c8b 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ToOneReferenceMapping.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/ToOneReferenceMapping.java
@@ -19,9 +19,9 @@ import org.eclipse.emf.cdo.protocol.model.CDOFeature;
  */
 public class ToOneReferenceMapping extends AttributeMapping.AMObject
 {
-  public ToOneReferenceMapping(ValueMapping valueMapping, CDOFeature feature)
+  public ToOneReferenceMapping(ClassMapping classMapping, CDOFeature feature)
   {
-    super(valueMapping, feature);
+    super(classMapping, feature);
   }
 
   @Override
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/VerticalMapping.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/VerticalClassMapping.java
index 8f92f88daf..8bb3a3ea27 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/VerticalMapping.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/VerticalClassMapping.java
@@ -13,7 +13,7 @@ package org.eclipse.emf.cdo.server.internal.db;
 import org.eclipse.emf.cdo.internal.protocol.revision.CDORevisionImpl;
 import org.eclipse.emf.cdo.protocol.model.CDOClass;
 import org.eclipse.emf.cdo.server.db.IDBStoreAccessor;
-import org.eclipse.emf.cdo.server.db.IMapping;
+import org.eclipse.emf.cdo.server.db.IClassMapping;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -21,21 +21,21 @@ import java.util.List;
 /**
  * @author Eike Stepper
  */
-public class VerticalMapping extends ValueMapping
+public class VerticalClassMapping extends ClassMapping
 {
-  private List<IMapping> superMappings;
+  private List<IClassMapping> superMappings;
 
-  public VerticalMapping(VerticalMappingStrategy mappingStrategy, CDOClass cdoClass)
+  public VerticalClassMapping(VerticalMappingStrategy mappingStrategy, CDOClass cdoClass)
   {
     super(mappingStrategy, cdoClass, cdoClass.getFeatures());
     for (CDOClass superType : cdoClass.getSuperTypes())
     {
-      IMapping superMapping = mappingStrategy.getMapping(superType);
+      IClassMapping superMapping = mappingStrategy.getClassMapping(superType);
       if (superMapping != null)
       {
         if (superMappings == null)
         {
-          superMappings = new ArrayList<IMapping>(0);
+          superMappings = new ArrayList<IClassMapping>(0);
         }
 
         superMappings.add(superMapping);
@@ -55,7 +55,7 @@ public class VerticalMapping extends ValueMapping
     return false;
   }
 
-  public List<IMapping> getSuperMappings()
+  public List<IClassMapping> getSuperMappings()
   {
     return superMappings;
   }
@@ -66,7 +66,7 @@ public class VerticalMapping extends ValueMapping
     super.writeRevision(storeAccessor, revision);
     if (superMappings != null)
     {
-      for (IMapping superMapping : superMappings)
+      for (IClassMapping superMapping : superMappings)
       {
         superMapping.writeRevision(storeAccessor, revision);
       }
diff --git a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/VerticalMappingStrategy.java b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/VerticalMappingStrategy.java
index ad52612ca8..f9caac8b9f 100644
--- a/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/VerticalMappingStrategy.java
+++ b/plugins/org.eclipse.emf.cdo.server.db/src/org/eclipse/emf/cdo/server/internal/db/VerticalMappingStrategy.java
@@ -11,7 +11,7 @@
 package org.eclipse.emf.cdo.server.internal.db;
 
 import org.eclipse.emf.cdo.protocol.model.CDOClass;
-import org.eclipse.emf.cdo.server.db.IMapping;
+import org.eclipse.emf.cdo.server.db.IClassMapping;
 
 import java.util.Collections;
 import java.util.List;
@@ -21,7 +21,7 @@ import java.util.List;
  */
 public class VerticalMappingStrategy extends MappingStrategy
 {
-  private RootMapping rootMapping;
+  private RootClassMapping rootMapping;
 
   public VerticalMappingStrategy()
   {
@@ -38,20 +38,20 @@ public class VerticalMappingStrategy extends MappingStrategy
     return true;
   }
 
-  public RootMapping getRootMapping()
+  public RootClassMapping getRootMapping()
   {
     if (rootMapping == null)
     {
-      rootMapping = new RootMapping(this);
+      rootMapping = new RootClassMapping(this);
     }
 
     return rootMapping;
   }
 
   @Override
-  protected IMapping createMapping(CDOClass cdoClass)
+  protected IClassMapping createClassMapping(CDOClass cdoClass)
   {
-    return new VerticalMapping(this, cdoClass);
+    return new VerticalClassMapping(this, cdoClass);
   }
 
   @Override