Oracle7 Server Application Developer's Guide
Writing SQL
All operations performed on the information in an Oracle database are executed using SQL statements. After you have completed the design of your application, you need to begin designing the SQL statements that you will use to implement this design. You should have a thorough understanding of SQL before you begin to write your application. A general description of how SQL statements are executed is provided in Chapter 3 of this document. For more detailed information, see the Oracle7 Server SQL Reference manual.
You can significantly improve the performance of your application by tuning the SQL statements it uses. Tuning SQL statements is explained in detail in the Oracle7 Server Tuning manual.