=== modified file 'dhis-2/dhis-services/dhis-service-datamart-default/src/main/java/org/hisp/dhis/datamart/aggregation/cache/MemoryAggregationCache.java'
--- dhis-2/dhis-services/dhis-service-datamart-default/src/main/java/org/hisp/dhis/datamart/aggregation/cache/MemoryAggregationCache.java	2010-06-17 22:42:56 +0000
+++ dhis-2/dhis-services/dhis-service-datamart-default/src/main/java/org/hisp/dhis/datamart/aggregation/cache/MemoryAggregationCache.java	2010-07-04 08:53:02 +0000
@@ -32,7 +32,6 @@
 import java.util.HashMap;
 import java.util.Map;
 
-import org.hisp.dhis.organisationunit.OrganisationUnitHierarchy;
 import org.hisp.dhis.organisationunit.OrganisationUnitService;
 import org.hisp.dhis.period.Period;
 import org.hisp.dhis.period.PeriodService;
@@ -40,7 +39,6 @@
 
 /**
  * @author Lars Helge Overland
- * @version $Id: MemoryAggregationCache.java 4646 2008-02-26 14:54:29Z larshelg $
  */
 public class MemoryAggregationCache
     implements AggregationCache
@@ -51,14 +49,10 @@
     // Cache
     // -------------------------------------------------------------------------
 
-    private final ThreadLocal<OrganisationUnitHierarchy> latestHierarchyCache = new ThreadLocal<OrganisationUnitHierarchy>();
-    
-    private final ThreadLocal<Map<String, Collection<OrganisationUnitHierarchy>>> hierarchyCache = new ThreadLocal<Map<String,Collection<OrganisationUnitHierarchy>>>();
-    
-    private final ThreadLocal<Map<String, Collection<Integer>>> childrenCache = new ThreadLocal<Map<String,Collection<Integer>>>();
-    
     private final ThreadLocal<Map<String, Collection<Integer>>> intersectingPeriodCache = new ThreadLocal<Map<String,Collection<Integer>>>();
 
+    private final ThreadLocal<Map<String, Collection<Integer>>> periodsBetweenDatesCache = new ThreadLocal<Map<String,Collection<Integer>>>();
+
     private final ThreadLocal<Map<String, Period>> periodCache = new ThreadLocal<Map<String,Period>>();
 
     private final ThreadLocal<Map<String, Integer>> organisationUnitLevelCache = new ThreadLocal<Map<String, Integer>>();
@@ -109,6 +103,30 @@
         return periods;
     }
     
+    public Collection<Integer> getPeriodsBetweenDates( final Date startDate, final Date endDate )
+    {
+        final String key = startDate.toString() + SEPARATOR + endDate.toString();
+        
+        Map<String, Collection<Integer>> cache = periodsBetweenDatesCache.get();
+        
+        Collection<Integer> periods = null;
+        
+        if ( cache != null && ( periods = cache.get( key ) ) != null )
+        {
+            return periods;
+        }
+        
+        periods = ConversionUtils.getIdentifiers( Period.class, periodService.getPeriodsBetweenDates( startDate, endDate ) );
+        
+        cache = ( cache == null ) ? new HashMap<String, Collection<Integer>>() : cache;
+        
+        cache.put( key, periods );
+        
+        periodsBetweenDatesCache.set( cache );
+        
+        return periods;
+    }
+    
     public Period getPeriod( final int id )
     {
         final String key = String.valueOf( id );
@@ -159,10 +177,9 @@
     
     public void clearCache()
     {
-        latestHierarchyCache.remove();
-        hierarchyCache.remove();
-        childrenCache.remove();
         intersectingPeriodCache.remove();
+        periodsBetweenDatesCache.remove();
         periodCache.remove();
+        organisationUnitLevelCache.remove();
     }
 }