We have a table of UK postcodes which is around 2 Million entries. doesn’t take all that long to return on a query. You’d probably be better off with 1 large table. depends how many columns you are going to run and what you are storing. e.g i probably wouldn’t want to store 0.5 million blob fields but simple number/text will probably be ok. Just make sure you get your index’s correct to make it as fast as possible to search.