In this final lesson of the book, I will teach you about the Oracle8 Web Publishing Assistant, a new product that provides a simple yet very effective method of publishing database information on the World Wide Web. You will learn how to use the Web Publishing Assistant to create Web pages. I'll also introduce you to the new and exciting world of the Oracle Network Computing Architecture (NCA). Finally, you will learn about some of Oracle's products, including the Web Commerce server, the Web Application server, and data cartridges.
The Web Publishing Assistant is a new product with Oracle8 for NT for publishing Web pages. Rather than being a sophisticated system for creating Web pages on the fly, the Web Publishing Assistant is a lightweight, easy-to-use utility for creating Web pages from database data. These Web pages are static but are re-created on a regular basis, so they remain up to date.
Perform the steps that follow to extract data from an Oracle database and create a static Web page. Later you will take steps to instigate the automatic re-creation of this Web page on a regular basis. This allows you to keep Web page information current without having to access that data online.
The initial screen of the Oracle Web Publishing Assistant.
The main screen of Web Publishing Assistant; no Web pages have been created, so none are defined.
4. Regardless of how you invoked the wizard, you will now see the wizard's first screen. Use this screen to define the database connection that will be used to retrieve the data. This screen requires you to enter the following data. These values will be used for the database connection (see Figure 21.3).
NOTE: Access into Oracle is based on username, password, and database (SID). This allows multiple users to create Web pages based on their own access into the Oracle database.
NOTE: To simplify complex table accesses within the Web Publishing Assistant, you can use other means to create a view into these tables. After the view has been created you can use the Web Publishing Assistant and specify that view as the data source.
The first screen of the Create Web Page wizard.
The second screen of the Create Web Page wizard.
The third screen of the Create Web Page wizard.
The final screen of the Create Web Page wizard.
Summary of the actions taken by the Create Web Page wizard.
The main page of the Web Publishing Assistant; note that the new Web page appears on this screen.
The Web page created by the Web Publishing Assistant. Note the added graphics.
I think the Web Publishing Assistant is straightforward, easy to use, and quite effective. You simply rebuild a Web page on a regular basis from data in the database. You can modify the refresh rate and Web page template to suit your needs.
The Network Computing Architecture (NCA) is a framework developed in part by Oracle for network computing. The NCA can be used to define applications that can be run either over the Internet or an intranet.
The NCA is a common set of technologies and products designed to help all systems work more closely together. The NCA's purpose is to join database servers, application servers, and Web servers under a common architecture, open to all vendors, that applications can use to communicate with each other.
The NCA consists of many different components, and in this lesson I provide brief overviews of several. Some of these components consist of the standards that make up the NCA such as CORBA 2.0 and HTTP/HTML. Other components consist programming languages such as Java. Still other components consist of distributed objects, data cartridges, thin clients, and so on.
The NCA is based on open standards that are available to all vendors. These standards allow independent programs to work together and to fit into the architecture regardless of who developed them. The main standards that the NCA employs are CORBA 2.0 and HTTP/HTML. Due to the development of a standards-based architecture, all vendors have an equal chance of developing high-quality applications; no vendor receives special advantages.
The Common Object Request Broker Architecture (CORBA) standard is a specification developed by a consortium called the Object Management Group (OMG), which is made up of over 600 companies from all areas of the computer industry. The CORBA standard defines a distributed architecture with an open communication channel between objects. When vendors program to this communication channel, their application can communicate and exchange information with other CORBA-compliant applications.
TCP/IP has been defined as the network-transport protocol for intersystem communication. For communication between different systems, an Internet Object Request Broker has been defined. This Internet Object Request Broker uses TCP/IP as its transport layer. If one adheres to these standards, intersystem and inter-OS communication is possible.
The Hypertext Transport Protocol (HTTP) defines today's World Wide Web. This standard allows Web browsers to communicate with Web servers. This protocol, in conjunction with the Hypertext Markup Language (HTML), is what makes Web browsers work.
HTTP is the specification that defines the communication between servers and browsers. This specification is freely available to all vendors; indeed, it is freely available via the World Wide Web. Simply go to your favorite search engine and search for HTTP.
HTML is the language used to define Web pages. If you look at the source code of a Web page, you will see the HTML code that builds that page.
Web browsers use HTTP to communicate and HTML to define what they will be displaying on the Web page. It is necessary for both of these components to exist for you to properly receive and display World Wide Web information.
The NCA is made up of various components that work together to form the architecture. These components include
Applications are the most visible part of the NCA because they are what you, the end user or developer, will work with. The applications that comprise the NCA include but are not limited to the following:
These components have one goal: to deliver information to the user. This delivery of information can occur regardless of the operating system of the client or server, and regardless of the brand of Web browser you use, as long as these components meet the specification.
The application server is one of the NCA's key components. An application server is essentially a Web server that supports application cartridges for HTTP/HTML-based programs. You can think of application servers as controlling the application. Application servers, in conjunction with the database servers, provide the application code and data that end-users need and want.
The Oracle Universal Server provides the performance and scalable data storage that today's applications demand. With the advent of the NCA, the Universal Server has been extended to provide many new data types to accommodate the type of corporate data used today. These new data types include
These data types, in conjunction with traditional data types, provide a full spectrum of information to the user.
Web clients have become fairly standard, but tremendous competition remains as new technologies develop every day. What is important is that along with any proprietary components added to the Web browser, the core standards such as HTML and Java are available. In this way you can develop applications that adhere to these standards without worrying about whether they'll work on certain systems.
I prefer to program to the lowest common denominator by not using proprietary extensions. If you do the same, your application will work on a variety of platforms without requiring major rewriting of code.
The Network Computer
Oracle and others are working on a new type of system called the Network Computer (NC), which is essentially a thin client or Internet Web browser in a box. The NC is very inexpensive and has the advantage of no operating system and no disk drive. Having no OS and no disk drive means that there are fewer parts to break. The component of a computer system that is most likely to fail is the disk drive because disk drives are mechanical and will eventually wear out.
I think the NC will supplement, not supersede, the PC. There are many circumstances where a PC and its local storage are not required, and the NC will work well in those cases. For example, to provide Web access to guests in a hotel, you would not want to place PCs in every room. With a PC you would have to reformat the disk and reload the OS after each guest departed to guarantee that the he or she did not leave any information on the system. Other examples of circumstances where NCs would work nicely include any places where a traditional terminal is in use and more data access is necessary, such as
Cartridges are plug-in applications that are typically specific to a single application. You can provide a wide range of applications by installing several different cartridges that can work together.
Think of a cartridge as an object that might serve one or more purposes. This object uses an Interface Definition Language (IDL) that allows it to identify itself to other objects in a distributed system. A cartridge can be written in a variety of languages, such as Java, Visual Basic, C++, SQL, and so on.
The cartridge itself also uses a software bus called the Inter-Cartridge Exchange (ICX). ICX allows cartridges that are part of a distributed system to communicate with each other. With ICX, a cartridge can communicate with other cartridges, clients, servers, database servers, and so on.
Other key components of the NCA are the components and standards that comprise it, such as TCP/IP, HTML/HTTP, and CORBA 2.0. These were described earlier today in the section on NCA standards.
Today you learned about the Web Publishing Assistant and were introduced to the Oracle Network Computing Architecture (NCA). The Web Publishing Assistant is a new and innovative product that creates Web pages accessible by whatever Web server you use. These static Web pages are periodically updated by the Web Publishing Assistant. The NCA standard specification is designed to join database servers, application servers, and Web servers under a common architecture to allow common access over a network. This infrastructure is open to all vendors to promote a common architecture that applications can use to communicate with each other. In this lesson you were introduced to the NCA and the components that comprise it, such as CORBA, HTTP/HTML, and Java. The NCA is just getting started; you will hear more and more about it in the next few years.
As you have seen in the past 21 days, the Oracle Server product offers a tremendous amount of information and functionality. The purpose of this book has been to introduce the Oracle8 server. Nonetheless, I have tried to be thorough; there was so much information in many cases that I was required to speak at a more advanced level.
I hope these 21 days gave you the knowledge necessary to perform the functions of an Oracle DBA or an informed user, but book knowledge is no substitute for experience. Your next step is to practice and gain experience as an Oracle8 DBA or user.
Because you have finished reading the book, your next step is to practice what you have learned. I hope you have access to an Oracle8 system and can use Enterprise Manager to build databases, tablespaces, and tables. Try different things to see what new skills you can acquire. If you have problems grasping a function or concept, don't give up. If you persevere, you will eventually understand. Fully understanding each component will serve you well in the long run; most aspects of the Oracle RDBMS build on each other.
Database technology is an exciting field that changes every day; new products and new technologies generate tremendous excitement. So above all, enjoy.
A The Web Publishing Assistant is used to create static Web pages from database data on a regular basis.
Q What is the difference between the Web Publishing Assistant and the Oracle Web Application Server?
A The Oracle Web Publishing Assistant creates static Web pages from database data whereas the Web Application Server dynamically creates Web pages based on database data.
Q What is the NCA?
A The NCA, or Network Computing Architecture, is a set of standards that defines how computing over the Internet or an intranet will be conducted in the future.
Q What is the NC (Network Computer)?
A The NC is a thin client or computer that is designed to run network applications without using local disk storage or an operating system.
The workshop provides quiz questions to help you solidify your understanding of the material covered and exercises to provide you with experience in using what you've learned. For answers to quiz questions, see Appendix A, "Answers."
2. What does CORBA stand for?
3. What is HTTP?
4. What is HTML?
5. What is a cartridge?
6. What is a static Web page?
7. What kind of Web pages can you create with the Web Publishing Assistant?
8. What is an NC?
9. What new types of data can the Oracle Universal Server handle?
10. What types of applications would be suitable for an NC?
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