According to PhpMyAdmin:
xf_post: 134.6mb (~240,912 rows)
xf_search: 248.6mb (~27,589 rows)
xf_search_index: 187.6mb (209,680 rows)
I doubt my users are generating 20K+ searches a day.
As well... shouldn't the number of rows in xf_search_index be the same as xf_post?