I have a query that pulls from small tables in MySQL:
SELECT C.cid, C.email, R.flight_number FROM customer C INNER JOIN reservation R ON C.cid = R.cid WHERE C.email LIKE '%d.com';
There exists an index in the customer table on the email column.
Based on what I've read on the subject, my thinking is that a full index scan would only slow down the query, and performing a full table scan and ignoring the index would be better than performing a full index scan in this case. However the visual plan shows that the query uses a full index scan over a full table scan. Why?