private void assignIDsToTuples() throws MainException{
		try{
			for(int i=0; i<nodeTables.size(); i++){
				String tableName = nodeTables.get(i);
				CachedRowSet keyData = tableKeyData.get(tableName);
				List<String> keyCols = keyMaps.get(tableName);
				int k = 1; 
				while(keyData.next()){
					String id = tableName + k;
					List<String> keyVals = getSelectedVals(tableName, keyCols, keyData);
					TupleIDMap tidm = new TupleIDMap(tableName, id, keyVals);
					List<TupleIDMap> tim = tableDataIDs.get(tableName);
					tim.add(tidm);
					k++;
				}
			}
		}catch(SQLException ex){

		}
	}