Changing Data Keys after init

I have search to find a solution but I guess I'm not searching for the right thing.

$('#example').DataTable( {
    data: data,
    columns: [
        { data: 'name' },
        { data: 'position' },
        { data: 'salary' },
        { data: 'office' }
    ]
} );

I am attempting to change the data keys after I create the DataTable. If it helps I am currently using

            oTable.fnClearTable();
            oTable.fnAddData(this.get("controller.currentTableData"));

to push new data into the table but the keys have changed with the new data.