DBUnit dataset export by set of primery key.

Question

I tried to export a dataset from an oracle database by a set of primery keys using:

TablesDependencyHelper.getDataset(connection, fullTableName , 
                    new TreeSet(Arrays.asList(
                        new BigDecimal[]{new BigDecimal(1)})));

That throws me a data file of 45mb!!!, checking the file I realize that the problem was a reference to a table with composite key(6 foreign keys), instead of exporting the unique referenced registry, it took the whole table data. ¿I think this is a bug of DBUnit, anyone knows a solution to this aproach?