I need to add a text field to a table, but at most, only about 5% of the records in the table will ever use this text field, the rest will just hold a NULL value.

My question is whether it would be better design or not to make another table for this text field with a 1-to-1 relationship to the existing table.

Thanks a lot for you input,
Greg

A NULL column shouldn't occupy much space (if any) so there should be harm in having the column in the main table. In Oracle, if the column is at the end of the row it will take up NO space when empty.