Output issue after data source modification

Hi experts,

I modified a flat file datasource by reducing the number of fields used.

Now, when i load data to DSO, i have the value of a field showed with 20 char but before only 3 chars were showed, and also 3 chars are shown in the other environments.

I'm afraid of this output modification because we have some abap tests on this field. So what can i do to show the values as before.

Thanks.

Amine