Bug 192132 [enhancement] reduce numbers of queries being executed for olap and xtab report
steps to reproduce: - use the attached report - preview in web viewer by profiling execution at web server and database server, it was noticed that when defining a data cube, each dimension executed new query requiring data from database, even though there was only one based table used by the data cube. could we enhance it by doing it once, then slice dimension data from query result?
data/org.eclipse.birt.report.data.adapter/src/org/eclipse/birt/report/data/adapter/impl/DataRequestSessionImpl.java
{
		assert dataSet != null;
		
		
		
		
		
		
		QueryDefinition query = new QueryDefinition( );
		query.setDataSetName( dataSet.getQualifiedName( ) );
		GroupDefinition group = new GroupDefinition( boundColumnName );
		group.setKeyColumn( boundColumnName );
		query.addGroup( group );
		query.setUsesDetails( false );
		ModuleHandle moduleHandle = sessionContext.getModuleHandle( );
		if ( moduleHandle == null )
			moduleHandle = dataSet.getModuleHandle( );
		QueryExecutionHelper execHelper = new QueryExecutionHelper( this.dataEngine,
				this.modelAdaptor,
				this.sessionContext );
		IQueryResults results = execHelper.executeQuery( query,
				inputParamBindings,
				null,
				columnBindings );
		return results;
	}
	/**
	 * This method is used to validate the column binding to see if it contains aggregations.
	 * If so then return true, else return false;
	 *