The most compelling reason to write scripts, in my mind, is to encapsulate knowledge. Suppose, for example, that you have developed a query that returns index definitions for a table. You certainly don't want to have to think through the entire process of developing that query each time you need to see an index. If you have a good script available, you just run it. Likewise, if someone asks you how to see index definitions for a table, you can give them a copy of the script.
Another reason for developing scripts is that they save time and effort, making it easy to run a series of commands repeatedly. Look at the script in Example 5-5 used to produce the Project Hours and Dollars Report. It contains 16 commands, some quite long. Who wants to retype all that each time they generate a report? I sure don't, do you?
Finally, scripts can simplify tasks for you and others. When you know you have a good, reliable script, you can run it, answer the questions, and sit back while it does all the work. You don't need to worry, thinking "Did I enter the correct command?" "Did I log on as the correct user ?" "Did I get that query just right?"
Any time you find yourself performing a task repeatedly, think about writing a script to do it for you. You'll save yourself time. You'll save yourself stress. You'll be able to share your knowledge more easily.
Introduction to SQL*Plus
A Lightning SQL Tutorial
Generating Reports with SQL*Plus
Creating HTML Reports
Writing SQL*Plus Scripts
Extracting and Loading Data
Exploring Your Database
Tuning and Timing
The Product User Profile
Customizing Your SQL*Plus Environment
Appendix A. SQL*Plus Command Reference
Appendix B. SQL*Plus Format Elements
Oracle SQL*Plus: The Definitive Guide (Definitive Guides)
Authors: Jonathan Gennick