General rules for simplifying SQL statements

Question

I\'m looking for some \"inference rules\" (similar to set operation rules or logic rules) which I can use to reduce a SQL query in complexity or size. Does there exist some

Answer 1

Given the nature of SQL, you absolutely have to be aware of the performance implications of any refactoring. Refactoring SQL Applications is a good resource on refactoring with a heavy emphasis on performance (see Chapter 5).