Jon Heller - Pro Oracle SQL Development: Best Practices for Writing Advanced Queries

Declarative: Declarative languages let us tell the computer what we want, without having to specify how to do it. Declarative languages are different than traditional imperative languages and can be difficult at first. (Whenever we find ourselves wanting to use a loop in SQL, thats a clue were thinking in the wrong programming paradigm.) Declarative languages let the compiler handle the details, leading to simpler and faster code. But if we need to control exactly how our code runs, we still have imperative options, such as PL/SQL, hints, and the MODEL clause.

Popular: Oracle is one of the most popular databases in the world. And SQL is one of the most popular programming languages in the world.

Portable: SQL and PL/SQL are entirely platform independent. Other than a rare bug, we never need to worry about which operating system is running our SQL.

Clear and concise: The basic syntax is simple and readable, and the relational model is built on a few simple ideas. (If this description doesnt match your reality, Part III will explain how to make your code look better.)

Interpreted: Statements run immediately, without a separate compilation step. Integrated development environments can take advantage of interpreted languages and let us instantly run programs, debug our code, and get results.

Powerful: Oracle SQL has enough features to solve almost any problem. For those rare exceptions, PL/SQL can handle them and integrate perfectly with SQL.

Fast: Oracle SQL is powerful enough to let us bring algorithms to our data, instead of bringing data to our algorithms. Ignore those shallow benchmarks that compare running SELECT COUNT(*) FROM EMPLOYEE a thousand times. Real-world performance is more complicated than that and depends more on an optimizer than the speed of running trivial commands.

Database developers: If youre already frequently using an Oracle database, then you have the most to gain from this book. This book will help you with many phases of your software development life cycle. Even if you already know many of the advanced features, you will still benefit from the discussions about setting up the environment, SQL programming styles, and SQL performance tuning.

Application/front end/full stack developers: Many applications only use simple queries like SELECT * FROM EMPLOYEES or have a framework that automatically takes care of database access. This book wont try to convince you to put all your business logic inside the database. But it will help you find great opportunities to simplify your code and improve performance, by using new SQL programming styles and advanced features.

Data analysts and testers: Oracle SQL is the perfect language for analyzing, testing, and comparing data. Much of the advice in this book will help with those tasks.

Data scientists: You probably wont use Oracle SQL for data mining (although Oracle does have a data mining option). But if youre reading or writing to an Oracle database, Oracles advanced features can at least help you with much of the tedious processing and formatting.

Database administrators: SQL is the life blood of an Oracle database. If you administer Oracle, youll need to work with those SQL statements and help others improve them. And there are many times when an advanced SQL statement can help you perform administrative tasks better.