SQL programmers have very different goals from DBA's. To a programmer, the main goal is to get a working SQL statement as quickly as possible
without any regard for the performance of the SQL statement. This problem is compounded by the declarative nature of Oracle SQL, where any
single requirement can be fulfilled by many SQL statements, each producing the same result set but with radically different execution times.
The purpose of this module is to show you how to work with and educate your SQL programmers about the issues surrounding SQL tuning.
Databases have been in use long before the personal computer became readily available.
IBM developed the Structured Query Language standard more than 50 years ago as a way to retrieve data from their new “relational” database. A decade later, Oracle released the first commercial relational database that used SQL, and
SQL has become the de-facto query language for relational databases.
The history of database research over the past 30 years is one of exceptional productivity that has led to the database system becoming arguably the most important development in the field of software engineering. The database is now the underlying framework of the information system, and has fundamentally changed the way many organizations operate.
In particular, the developments in this technology over the last few years have produced systems that are more powerful and more intuitive to use.
This has resulted in database systems becoming increasingly available to a wider variety of users.
Unfortunately, the apparent simplicity of these systems has led to users creating databases and applications without the necessary knowledge to produce an effective and efficient system.
