I have two tables
For autocomplete purpose you can use the jQuery Autocomplete tool, it is easy to implement.
Now to get the data while autocomplete, you can use a cache mechanism(considering you dont have bulk data to come up as autocomplete feature..) around the database. An api(GET) functionality can be useful here.
In case the user need to see something that does not appear in autocomplete, a "GetData" or "Search" functionality will be needed that actually hits the database and updates the cache to help future users.
Hope it helps.