Chapter 7

1. INNER, OUTER, cross, natural, and self joins.
2. Returns only matching records from each joined table.
3. dbname.tablename AS a
4. LEFT, RIGHT, FULL, right excluding, and left excluding.
5. Includes all rows from the right table that don't match records in the left table.
6. Associates columns of the same name in the joined tables with each other. It's similar to an inner join or left outer join.
7. It returns a combination of every row from two tables.
8. UNION removes duplicates and UNION ALL doesn't.
9. By using DISTINCT in SELECT clause and an INNER JOIN.
10. By ensuring you use the indexes that are on the tables or by adding indexes to the tables.