All database compacts (or pack, or whatever they call them in each version)
do re-indexing as far as I know. Access definitely re-indexes it's files.
Keep in mind that it will not change the index number if the index is a key,
but it will reorder based upon that key or another indexed field. Therefore
if you use an alpha index on a field in a table with a autonumbered key, it
will re-index to the alpha field.