Please Explain - Index by Word

[Kay C Lan]

The online information is relatively brief and I understand the size
issues if you choose to enable 'Index by Word', but I'm wondering if
there any other advantages and disadvantages, when it should and
shouldn't be used, and any special 'features' of how to use it.

In particular I'm in the process of creating a very small database.
One of the tables = customers, and has fields = fullname, email,
phone.

I've entered only 1 record for testing purposes: John Doe,
johndoe at email.com, 555 5555-5555

With 'index by word' selected if I

SELECT fullname,email FROM customer WHERE fullname = 'John Doe'

Nothing is returned and I get this in the Warning pane:

Index-By_Words search : FindValue customers::fullname

If I change the search from = to LIKE:

SELECT fullname,email FROM customer WHERE fullname LIKE 'John Doe'

I get what I originally expected

John Doe, johndoe at email.com

If I turn 'index by Word' off and do the original = search I get

John Doe, johndoe at email.com

Is that the correct output. If I use 'Index by Words' should I not use
= but use LIKE for my SELECT statements even if I'm looking for an
exact match?

I've reindexed the fields, tables, database. Defraged and compacted
the database. No change.

Any insight appreciated.