Setting Up an Oracle Environment
If you want to set up a typical PL/SQL environment, you need the following components:
- Database server: This is a computer (or set of computers) that runs the Oracle database. Oracle runs in many popular computer environments. The most commonly used with Oracle are UNIX, Linux, or some version of Microsoft Windows.
- PL/SQL usually runs on the database server. But Oracle also has a number of products that can use PL/SQL (Forms Developer 10g, Reports Developer 10g, and so on).
- Database Management system (DBMS): This is the Oracle software itself. This software is installed on the database server. You must have this installed prior to creating a database.
- Database: A database is primarily a set of tables and data that constitute the persistent (permanent) information for your system. You will also store many other things in the database such as code, indexes (to help queries run faster), and so on. Most of the interesting things you can do with a database (for example, Java classes, snapshots, and links to other databases) are beyond the scope of this book.
- When you install the database software, Oracle gives you the option of installing a sample database. If you take advantage of this option, it can help you get started.
- Application server: This is the computer where your application code is stored and executed. Now that most application development is done for the Web, you need a place to store and execute these programs. Those programs are usually executed on an application server. They can also be run on any common operating system, but are usually run on Microsoft Windows or UNIX.
- Application server software: To make applications work on an application server, you need special software to manage and run those programs. The most commonly used products are Orion and Apache. In an Oracle environment, you often see Oracle's own application server, called Internet Application Server (IAS), which is an extension of the Orion server software.
- Client computer and software: Batch routines are usually run directly on the database server, but client programs are run from a PC. Web applications are run on an Internet browser, and client/server programs execute directly on the client PC. Web applications mainly run on the application server and present the screen output to the client machine only through the browser.
- Network: The database server, application server and client computers have to be able to talk to each other through some kind of network or over the Internet.
If you're setting up an environment just to figure out how PL/SQL works, you at least need access to a database server and a client PC. If you're trying to learn from home, you can put everything on the same computer. (This assumes that you have a fairly powerful PC.)
Hardware and software requirements
If you're connecting to an existing Oracle database on a dedicated server, you don't need a very powerful machine. However, if you want to run the entire Oracle environment on the same PC, you need a PC with sufficient resources to run smoothly. You can use Oracle's listed minimum requirements as a guideline for the required hardware and software. However, you'll have an easier time if you have the following hardware and/or software resources available:
- CPU: Intel Pentium 4 or AMD Athlon 1.5 GHz and up.
- Memory: 1GB or more.
- Hard disk drive: 2.5GB or more free.
- Operating system:
• Microsoft-based: MS Windows 2000 or MS Windows XP.
• UNIX-based: If your workstation is UNIX-based, you're probably pretty technical already. Check the OTN (see below) for any issues you will need to consider.
- Security software: Oracle uses multiple TCP/IP ports, so be careful when configuring firewalls. If the database is trying to access something via TCP/IP, don't block it. This issue arose recently when Microsoft provided a built-in firewall for Windows XP Service Pack 2, and many users had configuration problems. Therefore, expect some firewall messages to pop up after the installation.
Accessing the Oracle Technology Network
Oracle Corporation supports a forum to publicize technical information called the Oracle Technology Network (OTN). The OTN contains a wealth of information for Oracle professionals. Because PL/SQL is the language of Oracle databases, the OTN includes many valuable resources to help you discover how to use PL/SQL effectively.
The OTN Web site gives you access to learning materials, discussion forums, documentation libraries, and best of all, a place from which to download the software. Because of the large size of some of the files, a reasonably fast connection speed is probably a must.
To register, go to the OTN Web site and click the New OTN Visitors link. Then click the Join OTN link, and on the next page, click the line to create an account. Registration is free, very simple, and should take you only a minute or two.
After you register, you're all set to download whatever you need (free of charge as long as you're just getting to know Oracle).
Installing the database
As of this writing, the most current version is called Oracle Database 10g. For getting to know PL/SQL, you should install the latest version of 10g available for your environment. This will allow you to practice with all the available new features. With every release, Oracle improves the PL/SQL language by adding new features and improving performance.
Which version should you use? The Enterprise Edition is preferable because it includes some features that you might be interested in later during your work with PL/SQL.
After you've downloaded the appropriate version of the database, you need to install it. Here's some helpful information that you should be aware of during the database installation process:
- Be sure to record the service name of the database when you install it.
- A preconfigured database with example schemas is very helpful. (Schemas are sets of objects belonging to the particular database user. If an object belongs to the user SCOTT, it is part of schema SCOTT.)
- Don't forget to unlock and set passwords for the most common schemas (SCOTT, HR, OE).
- The OTN contains a lot of useful information, including the whole Oracle documentation library. Check out the Quick Installation Guide (preferable for beginners) or the Installation Guide for installation details specific to your operating system. Both guides include steps that are fairly easy to follow.
If you've had some experience in installing other large products, you should be able to successfully install the database. Of course, as with any complex software, you might have some problems, but many Internet resources are available to help you if necessary.