anyone know how I can use

.textSearch()

using a partial match? e.g. "J" would return all records where the search column starts with a "J"

First if you can use like or ilike for column starts with that would be faster. Partial match for textsearch is 'J:*' but it will match any word that starts with J, not just the first. You should be able to google "postgres textsearch partial" or something like that and get many articles/discussions on it.