Bug 201013 [Automation][Regression]Invalid group key column name: _{$TEMP_GROUP_1$} occurs when preview attached report[1102]
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/QueryExecutor.java
odiQuery.setMaxRows( this.baseQueryDefn.getMaxRows( ) );
			
			prepareCacheQuery( this.odiQuery );
		}
		finally
		{
			Context.exit( );
		}
	}
	/**
	 * TODO: enhance me, this is only a temp logic
	 * Set temporary computed columns to DataSourceQuery where cache is used
	 */
	protected void prepareCacheQuery( IQuery odiQuery )
	{
		if ( odiQuery instanceof org.eclipse.birt.data.engine.executor.dscache.DataSourceQuery
				&& temporaryComputedColumns != null
				&& temporaryComputedColumns.size( ) > 0 )
		{
			( (org.eclipse.birt.data.engine.executor.dscache.DataSourceQuery) odiQuery ).setTempComputedColumn( this.temporaryComputedColumns );
		}
	}
	
	/**
	 * Populate grouping to the query.
	 * 
	 * @param cx
	 * @throws DataException
	 */
	private void populateGrouping( Context cx ) throws DataException