Using Primary Keys in Dataset's DataTable

Hi,

I have a dataset that has one table and 5 columns in it and I have set 2 columns in the dataset table as primary key Columns. Now, how can I make use of these primary key columns

For eg: If I want to say that get me all rows where PrimaryKeyColumn1 = '11' and primaryKeyColumn2 = '44' then how would I say that

Would I have to use DataTable.Select method

Dataset.Datable(0).Select ("PrimaryKeyColumn1 = 11 and primaryKeyColumn2 = 44)

If so, then whats the benefit of adding primary key columns I can still use the select statement as it is by specifying the same column names without adding the columns as primarykey columns in the dataset.

Thanks