[DS-732] Browse performance

git-svn-id: http://scm.dspace.org/svn/repo/dspace/trunk@5699 9c30dcfa-912a-0410-8fc2-9e0234be79fd

dspace-api/src/main/java/org/dspace/browse/BrowseCreateDAO.java

@@ -336,6 +336,8 @@ public interface BrowseCreateDAO
 	 * @throws BrowseException
 	 */
 	public String createCommunityView(String table, String view, boolean execute) throws BrowseException;
+
+    public List<Integer> deleteMappingsByItemID(String mapTable, int itemID) throws BrowseException;
 	
 	/**
 	 * Create the table which will hold the distinct metadata values that appear in multiple
@@ -385,7 +387,7 @@ public interface BrowseCreateDAO
      * @param withdrawn TODO
      * @throws BrowseException
      */
-    public void pruneMapExcess(String map, boolean withdrawn) throws BrowseException;
+    public void pruneMapExcess(String map, boolean withdrawn, List<Integer> distinctIds) throws BrowseException;
 
 	/**
 	 * So that there are no distinct values indexed which are no longer referenced from the
@@ -396,5 +398,5 @@ public interface BrowseCreateDAO
 	 * @param map		the name of the associated distinct mapping table.
 	 * @throws BrowseException
 	 */
-	public void pruneDistinct(String table, String map) throws BrowseException;
+	public void pruneDistinct(String table, String map, List<Integer> distinctIds) throws BrowseException;
 }

dspace-api/src/main/java/org/dspace/browse/BrowseCreateDAOOracle.java

@@ -805,18 +805,72 @@ public class BrowseCreateDAOOracle implements BrowseCreateDAO
         return true;
     }
 
+    public List<Integer> deleteMappingsByItemID(String mapTable, int itemID) throws BrowseException
+    {
+        List<Integer> distinctIds = new ArrayList<Integer>();
+        TableRowIterator tri = null;
+        try
+        {
+            tri = DatabaseManager.queryTable(context, mapTable, "SELECT * FROM " + mapTable + " WHERE item_id=?", itemID);
+            if (tri != null)
+            {
+                while (tri.hasNext())
+                {
+                    TableRow tr = tri.next();
+                    distinctIds.add(tr.getIntColumn("distinct_id"));
+                    DatabaseManager.delete(context, tr);
+                }
+            }
+        }
+        catch (SQLException e)
+        {
+            log.error("caught exception: ", e);
+            throw new BrowseException(e);
+        }
+        finally
+        {
+            if (tri != null)
+            {
+                tri.close();
+            }
+        }
+
+        return distinctIds;
+    }
+
     /* (non-Javadoc)
      * @see org.dspace.browse.BrowseCreateDAO#pruneDistinct(java.lang.String, java.lang.String)
      */
-    public void pruneDistinct(String table, String map) throws BrowseException
+    public void pruneDistinct(String table, String map, List<Integer> distinctIds) throws BrowseException
     {
         try
         {
-            String query = "DELETE FROM " + table +
+            StringBuilder query = new StringBuilder();
-                            " WHERE NOT EXISTS (SELECT 1 FROM " + map +
+            query.append("DELETE FROM ").append(table).append(" WHERE NOT EXISTS (SELECT 1 FROM ");
-                            " WHERE " + map + ".distinct_id = " + table +".id)";
+            query.append(map).append(" WHERE ").append(map).append(".distinct_id = ").append(table).append(".id)");
 
-            DatabaseManager.updateQuery(context, query);
+            if (distinctIds != null && distinctIds.size() > 0)
+            {
+                query.append(" AND ").append(table).append(".id IN (");
+                for (int i = 0; i < distinctIds.size(); i++)
+                {
+                    if (i > 0)
+                    {
+                        query.append(", ?");
+                    }
+                    else
+                    {
+                        query.append("?");
+                    }
+                }
+                query.append(")");
+
+                DatabaseManager.updateQuery(context, query.toString(), distinctIds.toArray(new Integer[distinctIds.size()]));
+            }
+            else
+            {
+                DatabaseManager.updateQuery(context, query.toString());
+            }
         }
         catch (SQLException e)
         {
@@ -832,10 +886,20 @@ public class BrowseCreateDAOOracle implements BrowseCreateDAO
     {
         try
         {
-            String itemCriteria = withdrawn ? "item.withdrawn = 1" : "item.in_archive = 1 AND item.withdrawn = 0";
+            StringBuilder query = new StringBuilder();
 
-            String delete = "DELETE FROM " + table + " WHERE NOT EXISTS (SELECT 1 FROM item WHERE item.item_id=" + table + ".item_id AND " + itemCriteria + ")";
+            query.append("DELETE FROM ").append(table).append(" WHERE NOT EXISTS (SELECT 1 FROM item WHERE item.item_id=");
-            DatabaseManager.updateQuery(context, delete);
+            query.append(table).append(".item_id AND ");
+            if (withdrawn)
+            {
+                query.append("item.withdrawn = 1");
+            }
+            else
+            {
+                query.append("item.in_archive = 1 AND item.withdrawn = 0");
+            }
+            query.append(")");
+            DatabaseManager.updateQuery(context, query.toString());
         }
         catch (SQLException e)
         {
@@ -847,14 +911,45 @@ public class BrowseCreateDAOOracle implements BrowseCreateDAO
     /* (non-Javadoc)
      * @see org.dspace.browse.BrowseCreateDAO#pruneMapExcess(java.lang.String, boolean)
      */
-    public void pruneMapExcess(String map, boolean withdrawn) throws BrowseException
+    public void pruneMapExcess(String map, boolean withdrawn, List<Integer> distinctIds) throws BrowseException
     {
         try
         {
-            String itemCriteria = withdrawn ? "item.withdrawn = 1" : "item.in_archive = 1 AND item.withdrawn = 0";
+            StringBuilder query = new StringBuilder();
 
-            String deleteDistinct = "DELETE FROM " + map + " WHERE NOT EXISTS (SELECT 1 FROM item WHERE item.item_id=" + map + ".item_id AND " + itemCriteria + ")";
+            query.append("DELETE FROM ").append(map).append(" WHERE NOT EXISTS (SELECT 1 FROM item WHERE item.item_id=");
-            DatabaseManager.updateQuery(context, deleteDistinct);
+            query.append(map).append(".item_id AND ");
+            if (withdrawn)
+            {
+                query.append("item.withdrawn = 1");
+            }
+            else
+            {
+                query.append("item.in_archive = 1 AND item.withdrawn = 0");
+            }
+            query.append(")");
+            if (distinctIds != null && distinctIds.size() > 0)
+            {
+                query.append(" AND ").append(map).append(".distinct_id IN (");
+                for (int i = 0; i < distinctIds.size(); i++)
+                {
+                    if (i > 0)
+                    {
+                        query.append(", ?");
+                    }
+                    else
+                    {
+                        query.append("?");
+                    }
+                }
+                query.append(")");
+
+                DatabaseManager.updateQuery(context, query.toString(), distinctIds.toArray(new Integer[distinctIds.size()]));
+            }
+            else
+            {
+                DatabaseManager.updateQuery(context, query.toString());
+            }
         }
         catch (SQLException e)
         {

dspace-api/src/main/java/org/dspace/browse/BrowseCreateDAOPostgres.java

@@ -802,19 +802,73 @@ public class BrowseCreateDAOPostgres implements BrowseCreateDAO
         return true;
     }
 
+    public List<Integer> deleteMappingsByItemID(String mapTable, int itemID) throws BrowseException
+    {
+        List<Integer> distinctIds = new ArrayList<Integer>();
+        TableRowIterator tri = null;
+        try
+        {
+            tri = DatabaseManager.queryTable(context, mapTable, "SELECT * FROM " + mapTable + " WHERE item_id=?", itemID);
+            if (tri != null)
+            {
+                while (tri.hasNext())
+                {
+                    TableRow tr = tri.next();
+                    distinctIds.add(tr.getIntColumn("distinct_id"));
+                    DatabaseManager.delete(context, tr);
+                }
+            }
+        }
+        catch (SQLException e)
+        {
+            log.error("caught exception: ", e);
+            throw new BrowseException(e);
+        }
+        finally
+        {
+            if (tri != null)
+            {
+                tri.close();
+            }
+        }
+
+        return distinctIds;
+    }
+
     /* (non-Javadoc)
      * @see org.dspace.browse.BrowseCreateDAO#pruneDistinct(java.lang.String, java.lang.String)
      */
-    public void pruneDistinct(String table, String map)
+    public void pruneDistinct(String table, String map, List<Integer> distinctIds)
         throws BrowseException
     {
         try
         {
-            String query = "DELETE FROM " + table +
+            StringBuilder query = new StringBuilder();
-                            " WHERE NOT EXISTS (SELECT 1 FROM " + map +
+            query.append("DELETE FROM ").append(table).append(" WHERE NOT EXISTS (SELECT 1 FROM ");
-                            " WHERE " + map + ".distinct_id = " + table +".id)";
+            query.append(map).append(" WHERE ").append(map).append(".distinct_id = ").append(table).append(".id)");
 
-            DatabaseManager.updateQuery(context, query);
+            if (distinctIds != null && distinctIds.size() > 0)
+            {
+                query.append(" AND ").append(table).append(".id IN (");
+                for (int i = 0; i < distinctIds.size(); i++)
+                {
+                    if (i > 0)
+                    {
+                        query.append(", ?");
+                    }
+                    else
+                    {
+                        query.append("?");
+                    }
+                }
+                query.append(")");
+
+                DatabaseManager.updateQuery(context, query.toString(), distinctIds.toArray(new Integer[distinctIds.size()]));
+            }
+            else
+            {
+                DatabaseManager.updateQuery(context, query.toString());
+            }
         }
         catch (SQLException e)
         {
@@ -829,6 +883,29 @@ public class BrowseCreateDAOPostgres implements BrowseCreateDAO
     public void pruneExcess(String table, boolean withdrawn)
         throws BrowseException
     {
+        try
+        {
+            StringBuilder query = new StringBuilder();
+
+            query.append("DELETE FROM ").append(table).append(" WHERE NOT EXISTS (SELECT 1 FROM item WHERE item.item_id=");
+            query.append(table).append(".item_id AND ");
+            if (withdrawn)
+            {
+                query.append("item.withdrawn = true");
+            }
+            else
+            {
+                query.append("item.in_archive = true AND item.withdrawn = false");
+            }
+            query.append(")");
+            DatabaseManager.updateQuery(context, query.toString());
+        }
+        catch (SQLException e)
+        {
+            log.error("caught exception: ", e);
+            throw new BrowseException(e);
+        }
+
         try
         {
             String itemCriteria = withdrawn ? "item.withdrawn = true" : "item.in_archive = true AND item.withdrawn = false";
@@ -846,15 +923,46 @@ public class BrowseCreateDAOPostgres implements BrowseCreateDAO
     /* (non-Javadoc)
      * @see org.dspace.browse.BrowseCreateDAO#pruneMapExcess(java.lang.String, boolean)
      */
-    public void pruneMapExcess(String map, boolean withdrawn)
+    public void pruneMapExcess(String map, boolean withdrawn, List<Integer> distinctIds)
         throws BrowseException
     {
         try
         {
-            String itemCriteria = withdrawn ? "item.withdrawn = true" : "item.in_archive = true AND item.withdrawn = false";
+            StringBuilder query = new StringBuilder();
 
-            String deleteDistinct = "DELETE FROM " + map + " WHERE NOT EXISTS (SELECT 1 FROM item WHERE item.item_id=" + map + ".item_id AND " + itemCriteria + ")";
+            query.append("DELETE FROM ").append(map).append(" WHERE NOT EXISTS (SELECT 1 FROM item WHERE item.item_id=");
-            DatabaseManager.updateQuery(context, deleteDistinct);
+            query.append(map).append(".item_id AND ");
+            if (withdrawn)
+            {
+                query.append("item.withdrawn = true");
+            }
+            else
+            {
+                query.append("item.in_archive = true AND item.withdrawn = false");
+            }
+            query.append(")");
+            if (distinctIds != null && distinctIds.size() > 0)
+            {
+                query.append(" AND ").append(map).append(".distinct_id IN (");
+                for (int i = 0; i < distinctIds.size(); i++)
+                {
+                    if (i > 0)
+                    {
+                        query.append(", ?");
+                    }
+                    else
+                    {
+                        query.append("?");
+                    }
+                }
+                query.append(")");
+
+                DatabaseManager.updateQuery(context, query.toString(), distinctIds.toArray(new Integer[distinctIds.size()]));
+            }
+            else
+            {
+                DatabaseManager.updateQuery(context, query.toString());
+            }
         }
         catch (SQLException e)
         {

dspace-api/src/main/java/org/dspace/browse/IndexBrowse.java

@@ -301,6 +301,16 @@ public class IndexBrowse
         dao.deleteByItemID(table, itemID);
     }
 
+    private void removeDistinctIndex(int itemID, String distinctTable, String mapTable)
+        throws BrowseException
+    {
+        List<Integer> distinctIds = dao.deleteMappingsByItemID(mapTable, itemID);
+        if (distinctIds != null && distinctIds.size() > 0)
+        {
+            dao.pruneDistinct(distinctTable, mapTable, distinctIds);
+        }
+    }
+
     /**
      * Prune indexes - called from the public interfaces or at the end of a batch indexing process
      */
@@ -312,8 +322,7 @@ public class IndexBrowse
             if (bis[i].isMetadataIndex())
             {
                 log.debug("Pruning metadata index: " + bis[i].getTableName());
-                dao.pruneMapExcess(bis[i].getMapTableName(), false);
+                pruneDistinctIndex(bis[i], null);
-                dao.pruneDistinct(bis[i].getDistinctTableName(), bis[i].getMapTableName());
             }
         }
 
@@ -321,6 +330,12 @@ public class IndexBrowse
         dao.pruneExcess(BrowseIndex.getWithdrawnBrowseIndex().getTableName(), true);
     }
 
+    private void pruneDistinctIndex(BrowseIndex bi, List<Integer> removedIds) throws BrowseException
+    {
+        dao.pruneMapExcess(bi.getMapTableName(), false, removedIds);
+        dao.pruneDistinct(bi.getDistinctTableName(), bi.getMapTableName(), removedIds);
+    }
+
     /**
      * Index the given item
      * 
@@ -344,7 +359,7 @@ public class IndexBrowse
             indexItem(new ItemMetadataProxy(item));
 
             // Ensure that we remove any invalid entries
-            pruneIndexes();
+            //pruneIndexes();
         }
     }
     
@@ -494,7 +509,7 @@ public class IndexBrowse
                     if (distIDSet.isEmpty())
                     {
                         // remove any old mappings
-                        removeIndex(item.getID(), bis[i].getMapTableName());
+                        removeDistinctIndex(item.getID(), bis[i].getDistinctTableName(), bis[i].getMapTableName());
                     }
                     else
                     {
@@ -506,6 +521,10 @@ public class IndexBrowse
                             distIDarr[didx++] = distID;
                         }
                         MappingResults results = dao.updateDistinctMappings(bis[i].getMapTableName(), item.getID(), distIDarr);
+                        if (results.getRemovedDistinctIds() != null && results.getRemovedDistinctIds().size() > 0)
+                        {
+                            pruneDistinctIndex(bis[i], results.getRemovedDistinctIds());
+                        }
                     }
                 }
             }
@@ -645,7 +664,7 @@ public class IndexBrowse
         dao.deleteCommunityMappings(itemID);
 
         // Ensure that we remove any invalid entries
-        pruneIndexes();
+        //pruneIndexes();
 
         return true;
 	}
@@ -1158,7 +1177,7 @@ public class IndexBrowse
     		
     		// penultimately we have to delete any items that couldn't be located in the
     		// index list
-            pruneIndexes();
+            //pruneIndexes();
             
             // Make sure the deletes are written back
             context.commit();

dspace-api/src/test/java/org/dspace/browse/MockBrowseCreateDAOOracle.java

@@ -36,6 +36,7 @@ package org.dspace.browse;
 
 import java.sql.SQLException;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
@@ -286,12 +287,10 @@ public class MockBrowseCreateDAOOracle
         }
     }
 
-    /* (non-Javadoc)
-     * @see org.dspace.browse.BrowseCreateDAO#updateDistinctMapping(java.lang.String, int, int)
-     */
     @Mock
-    public boolean updateDistinctMappings(String table, int itemID, int[] distinctIDs) throws BrowseException
+    public MappingResults updateDistinctMappings(String table, int itemID, int[] distinctIDs) throws BrowseException
     {
+        BrowseMappingResults results = new BrowseMappingResults();
         try
         {
             checkContext();
@@ -299,7 +298,9 @@ public class MockBrowseCreateDAOOracle
             for (int i = 0; i < distinctIDs.length; i++)
             {
                 if (!isFirstOccurrence(distinctIDs, i))
+                {
                     distinctIDs[i] = -1;
+                }
             }
 
             // Find all existing mappings for this item
@@ -320,6 +321,7 @@ public class MockBrowseCreateDAOOracle
                             // Found this mapping
                             if (distinctIDs[i] == trDistinctID)
                             {
+                                results.addRetainedDistinctId(trDistinctID);
                                 // Flag it, and remove (-1) from the item mappings
                                 itemIsMapped = true;
                                 distinctIDs[i] = -1;
@@ -328,7 +330,10 @@ public class MockBrowseCreateDAOOracle
 
                         // The item is no longer mapped to this community, so remove the database record
                         if (!itemIsMapped)
+                        {
+                            results.addRemovedDistinctId(trDistinctID);
                             DatabaseManager.delete(internalContext, tr);
+                        }
                     }
                 }
                 finally
@@ -338,14 +343,15 @@ public class MockBrowseCreateDAOOracle
             }
 
             // Any remaining mappings need to be added to the database
-            for (int i = 0; i < distinctIDs.length; i++)
+            for (int distinctID : distinctIDs)
             {
-                if (distinctIDs[i] > -1)
+                if (distinctID > -1)
                 {
                     TableRow row = DatabaseManager.create(internalContext, table);
                     row.setColumn("item_id", itemID);
-                    row.setColumn("distinct_id", distinctIDs[i]);
+                    row.setColumn("distinct_id", distinctID);
                     DatabaseManager.update(internalContext, row);
+                    results.addAddedDistinctId(distinctID);
                 }
             }
         }
@@ -360,7 +366,7 @@ public class MockBrowseCreateDAOOracle
             cleanContext();
         }
 
-        return false;
+        return results;
     }
 
     /* (non-Javadoc)
@@ -904,20 +910,84 @@ public class MockBrowseCreateDAOOracle
         return true;
     }
 
+    @Mock
+    public List<Integer> deleteMappingsByItemID(String mapTable, int itemID) throws BrowseException
+    {
+        System.out.println("Map: " + mapTable + ", item: " + itemID);
+        List<Integer> distinctIds = new ArrayList<Integer>();
+        TableRowIterator tri = null;
+        try
+        {
+            checkContext();
+            try
+            {
+                tri = DatabaseManager.queryTable(internalContext, mapTable, "SELECT * FROM " + mapTable + " WHERE item_id=?", itemID);
+                if (tri != null)
+                {
+                    while (tri.hasNext())
+                    {
+                        TableRow tr = tri.next();
+                        distinctIds.add(tr.getIntColumn("distinct_id"));
+                        DatabaseManager.delete(internalContext, tr);
+                    }
+                }
+            }
+            catch (SQLException e)
+            {
+                log.error("caught exception: ", e);
+                throw new BrowseException(e);
+            }
+            finally
+            {
+                if (tri != null)
+                {
+                    tri.close();
+                }
+            }
+        }
+        finally
+        {
+            cleanContext();
+        }
+
+        return distinctIds;
+    }
+
     /* (non-Javadoc)
      * @see org.dspace.browse.BrowseCreateDAO#pruneDistinct(java.lang.String, java.lang.String)
      */
     @Mock
-    public void pruneDistinct(String table, String map) throws BrowseException
+    public void pruneDistinct(String table, String map, List<Integer> distinctIds) throws BrowseException
     {
         try
         {
             checkContext();
-            String query = "DELETE FROM " + table +
+            StringBuilder query = new StringBuilder();
-                            " WHERE id IN (SELECT id FROM " + table +
+            query.append("DELETE FROM ").append(table).append(" WHERE NOT EXISTS (SELECT 1 FROM ");
-                            " MINUS SELECT distinct_id AS id FROM " + map + ")";
+            query.append(map).append(" WHERE ").append(map).append(".distinct_id = ").append(table).append(".id)");
 
-            DatabaseManager.updateQuery(internalContext, query);
+            if (distinctIds != null && distinctIds.size() > 0)
+            {
+                query.append(" AND ").append(table).append(".id IN (");
+                for (int i = 0; i < distinctIds.size(); i++)
+                {
+                    if (i > 0)
+                    {
+                        query.append(", ?");
+                    }
+                    else
+                    {
+                        query.append("?");
+                    }
+                }
+                query.append(")");
+
+                DatabaseManager.updateQuery(internalContext, query.toString(), distinctIds.toArray(new Integer[distinctIds.size()]));
+            }
+            else
+            {
+                DatabaseManager.updateQuery(internalContext, query.toString());
+            }
         }
         catch (SQLException e)
         {
@@ -934,26 +1004,77 @@ public class MockBrowseCreateDAOOracle
      * @see org.dspace.browse.BrowseCreateDAO#pruneExcess(java.lang.String, java.lang.String)
      */
     @Mock
-    public void pruneExcess(String table, String map, boolean withdrawn) throws BrowseException
+    public void pruneExcess(String table, boolean withdrawn) throws BrowseException
     {
         try
         {
             checkContext();
-            String itemQuery = "SELECT item_id FROM item WHERE ";
+            StringBuilder query = new StringBuilder();
+
+            query.append("DELETE FROM ").append(table).append(" WHERE NOT EXISTS (SELECT 1 FROM item WHERE item.item_id=");
+            query.append(table).append(".item_id AND ");
             if (withdrawn)
-                itemQuery += "withdrawn = 1";
-            else
-                itemQuery += "in_archive = 1 AND withdrawn = 0";
-
-            String delete = "DELETE FROM " + table + " WHERE item_id IN ( SELECT item_id FROM " + table + " MINUS " + itemQuery + ")";
-
-            DatabaseManager.updateQuery(internalContext, delete);
-
-            if (map != null)
             {
-                String deleteDistinct = "DELETE FROM " + map   + " WHERE item_id IN ( SELECT item_id FROM " + map   + " MINUS " + itemQuery + ")";
+                query.append("item.withdrawn = 1");
-                DatabaseManager.updateQuery(internalContext, deleteDistinct);
+            }
-                internalContext.commit();
+            else
+            {
+                query.append("item.in_archive = 1 AND item.withdrawn = 0");
+            }
+            query.append(")");
+            DatabaseManager.updateQuery(internalContext, query.toString());
+        }
+        catch (SQLException e)
+        {
+            log.error("caught exception: ", e);
+            throw new BrowseException(e);
+        }
+        finally
+        {
+            cleanContext();
+        }
+    }
+
+    @Mock
+    public void pruneMapExcess(String map, boolean withdrawn, List<Integer> distinctIds) throws BrowseException
+    {
+        try
+        {
+            checkContext();
+            StringBuilder query = new StringBuilder();
+
+            query.append("DELETE FROM ").append(map).append(" WHERE NOT EXISTS (SELECT 1 FROM item WHERE item.item_id=");
+            query.append(map).append(".item_id AND ");
+            if (withdrawn)
+            {
+                query.append("item.withdrawn = 1");
+            }
+            else
+            {
+                query.append("item.in_archive = 1 AND item.withdrawn = 0");
+            }
+            query.append(")");
+            if (distinctIds != null && distinctIds.size() > 0)
+            {
+                query.append(" AND ").append(map).append(".distinct_id IN (");
+                for (int i = 0; i < distinctIds.size(); i++)
+                {
+                    if (i > 0)
+                    {
+                        query.append(", ?");
+                    }
+                    else
+                    {
+                        query.append("?");
+                    }
+                }
+                query.append(")");
+
+                DatabaseManager.updateQuery(internalContext, query.toString(), distinctIds.toArray(new Integer[distinctIds.size()]));
+            }
+            else
+            {
+                DatabaseManager.updateQuery(internalContext, query.toString());
             }
         }
         catch (SQLException e)
@@ -1203,4 +1324,41 @@ public class MockBrowseCreateDAOOracle
 
         return true;
     }
+
+    private static class BrowseMappingResults implements MappingResults
+    {
+        private List<Integer> addedDistinctIds    = new ArrayList<Integer>();
+        private List<Integer> retainedDistinctIds = new ArrayList<Integer>();
+        private List<Integer> removedDistinctIds  = new ArrayList<Integer>();
+
+        private void addAddedDistinctId(int id)
+        {
+            addedDistinctIds.add(id);
+        }
+
+        private void addRetainedDistinctId(int id)
+        {
+            retainedDistinctIds.add(id);
+        }
+
+        private void addRemovedDistinctId(int id)
+        {
+            removedDistinctIds.add(id);
+        }
+
+        public List<Integer> getAddedDistinctIds()
+        {
+            return addedDistinctIds;
+        }
+
+        public List<Integer> getRetainedDistinctIds()
+        {
+            return retainedDistinctIds;
+        }
+
+        public List<Integer> getRemovedDistinctIds()
+        {
+            return Collections.unmodifiableList(removedDistinctIds);
+        }
+    }
 }