Note on Soundex searches: If this file is one in which search speed is more important than data entry speed (meaning you are adding records one at a time or in small batches rather than large batches) you may find in much faster to add a field to your database in which you store the soundex value of the phonetically searched field. You will find that searching on this fields with a straight index in MUCH faster than searching on a field using the SOUNDEX() fucntion in the index.

Note: This definitely violates normalization rules: if your program is using business objects you may be able to set up a rule in the business object so the two fields don't get out of synch. Otherwise you may want to set up triggers. As per Jim Booth, you will definitely want to document in that if the orginal fields and soundex conflict that the original is to be considered correct and the soundex recalculated.