Using an index

If you perform a lot of searches on one field, you can tell Access to index that field.…An Index is a stored set of data so that when you do a search or a filter,…Access already knows where that information lies.…This speeds up your search results, particularly when you're working with rare…or unusual pieces of information within a large number of records.…Access's Index works a lot like looking up a word in the index at the back of…the book, so you can find that term within the chapters.…But just like an index in the back of a book, you don't need to turn on a…field's index if much of the data is identical.…

That would be like looking at word The, which appears on every page.…If the data is everywhere an Index is of no benefit.…Your primary key field is automatically indexed.…You don't have to turn it on manually.…I am in my Customers table and I'm going to switch over to the Design View.…I'll click in the Company field, and then down in the Field Properties I see…Indexed, and right now it says No.…