The data in a date column in DB2 will always have the 4-digit year. This is intrinsic to the internal date format and you can not change it. Unless the dates were stored in varchar columns …
When you select the data then you can get the dates in different formats, or massage them at will.
In the <pre>SELECT </pre>sentence you can use the <pre>VARCHAR_FORMAT</pre> scalar function to make your dates look as you want.