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Introducing Oracle9iAS Discoverer

1.1 Introducing Oracle9iAS Discoverer

This chapter introduces Oracle9iAS Discoverer and contains the following topics:

• Section 1.2, "About this guide"

• Section 1.3, "What is Oracle9iAS Discoverer?"

• Section 1.4, "About Oracle9iAS Discoverer and Oracle9i Application Server"

• Section 1.5, "What is the Oracle9iAS Discoverer architecture?"

• Section 1.6, "About the Discoverer client tier"

• Section 1.7, "About the Discoverer Services tier"

• Section 1.8, "About the Discoverer database tier"

• Section 1.9, "How does Oracle9iAS Discoverer work?"

1.2 About this guide

This section explains how to find the information that you need to maintain and configure Discoverer. For example:

• you might have installed Oracle9iAS and want to run Discoverer Viewer and Discoverer Plus 'out of the box'

• you might have installed Oracle9iAS and now you want to set up a multi-machine configuration and use Web Cache to improve performance

• you might want to find out more about Discoverer's architecture

The table below lists configuration tasks and where to find information about each task.

What do you want to do?	Look in this chapter:
Change user preferences (e.g. query behavior, data format, default EUL)	Section 7.1, "Editing Discoverer preferences"
Configure Discoverer to work with firewalls and demilitarized zones	Section 13.1, "Maintaining data security with Discoverer"
Configure Discoverer using the Oracle Enterprise Manager (e.g. manage public connections, specify communications protocols for Discoverer Plus)	Section 2.1, "Using Discoverer with Oracle Enterprise Manager"
Customize the Discoverer Viewer user interface (e.g. fonts and styles)	Section 10.1, "Customizing Discoverer Viewer"
Deploy Oracle9iAS Discoverer in a multi-machine environment	Section 5.1, "Installing Oracle9iAS Discoverer in a multiple machine environment"
Deploy Oracle9iAS Discoverer with Oracle Applications	Section 14.2, "About Discoverer connections and Oracle Applications"
Deploy Oracle9iAS Discoverer with Oracle9iAS Portal	Section 11.1, "Using Discoverer with Oracle9iAS Portal"
Deploy Oracle9iAS Discoverer with Oracle9iAS Web Cache to improve performance	Section 9.1, "Using Discoverer with Oracle9iAS Web Cache"
Diagnose common problems with Oracle9iAS Discoverer	Section B.1, "Generating trace information in Discoverer"
Optimize Oracle9iAS Discoverer's performance (e.g. stylesheet pooling, query optimization)	Section 12.1, "Optimizing Discoverer performance and scalability"
Run Discoverer Plus or Discoverer Viewer to confirm a successful installation	Section 3.1, "Running Oracle9iAS Discoverer"
Run the Oracle9iAS demo in Discoverer	Section 3.2, "About the Oracle9iAS demo database"
Start Oracle9iAS Discoverer automatically from a Web URL or go straight to a particular workbook	Section 8.1, "Starting Discoverer using URL parameters"

The table below lists reference information chapters.

What do you want to find out more about?	Look in this chapter:
Oracle9iAS Discoverer configuration files (e.g. configuration.xml, blaf.css)	Section A.1, "Discoverer configuration files"
Oracle9iAS Discoverer maintenance (e.g. manually stopping and starting components)	Section 4.1, "Maintaining Oracle9iAS Discoverer"
Oracle9iAS Discoverer's architecture (e.g. Discoverer multi-tier structure)	Section 1.1, "Introducing Oracle9iAS Discoverer"
Frequently asked questions about Oracle9iAS Discoverer	Section C.1, "Frequently asked questions"
Oracle9iAS's CORBA components (e.g. session and preference components)	Section 6.1, "Managing the Discoverer CORBA components"

1.3 What is Oracle9iAS Discoverer?

Oracle9iAS Discoverer is a business intelligence tool for analyzing data and is a key component of Oracle9i Application Server (Oracle9iAS). Discoverer provides an integrated business intelligence solution comprising a set of intuitive ad-hoc query, reporting, analysis, and Web-publishing tools. These tools enable non-technical users to gain immediate access to information from data marts, data warehouses, and online transaction processing systems. Oracle9iAS Discoverer integrates seamlessly with Oracle9iAS Portal, enabling rapid deployment of Discoverer workbooks and worksheets to Web portals.

There are two Oracle9iAS Discoverer business analysis tools:

• Discoverer Plus is a Web tool enabling users to analyze data and create reports without having to understand difficult database concepts. Using Wizard dialogs and menus, Discoverer Plus guides users through the steps to create powerful reports and charts that can be accessed using Discoverer Plus or Discoverer Viewer.

  Figure 1-1 Oracle9iAS Discoverer Plus

  
  
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• Discoverer Viewer is a Web tool for accessing interactive reports and charts created using Discoverer Plus. Because Discoverer Viewer is implemented in HTML, users require only an Internet browser to run Discoverer Viewer. Discoverer Viewer can also be used to publish reports into a portal, and is easily customized to conform to a particular web site look and feel. Discoverer Viewer is optimized for performance and designed to minimize network traffic.

  Figure 1-2 Oracle9iAS Discoverer Viewer

  
  
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A typical workflow for Discoverer is:

• Discoverer Plus users (sometimes referred to as power users) create interactive reports and charts. Reports typically include powerful business intelligence components that enable end users to analyze data (e.g. parameters, drills, conditions, totals).

• Discoverer Viewer users access the interactive reports in read-only mode, though they can typically customize reports in a restricted number of ways (e.g. drilling to the data that they require, applying parameters and conditions).

1.4 About Oracle9iAS Discoverer and Oracle9i Application Server

Oracle9iAS Discoverer is installed as part of Oracle9i Application Server. The default installation is to install all Discoverer components on a single machine. However, you can install different components on different machines to improve performance and reliability (for more information, refer to Chapter 5.1, "Installing Oracle9iAS Discoverer in a multiple machine environment").

1.5 What is the Oracle9iAS Discoverer architecture?

Oracle9iAS Discoverer has a multi-tier architecture. This architecture takes advantage of the distributed nature of the Web environment. While it is possible to install all tiers of the Oracle9iAS Discoverer architecture on the same machine, we recommend distributing your installation over multiple machines to maximize performance and reliability.

Figure 1-3 Discoverer's multi-tier architecture

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Note: Multiple application servers can be installed on the same machine.

Discoverer's multi-tier architecture comprises:

• The Discoverer client tier, from which Web browsers access Discoverer (for more information, see Section 1.6, "About the Discoverer client tier").

• The Discoverer Services tier (also referred to as the Discoverer middle tier). For more information, see Section 1.7, "About the Discoverer Services tier".

• The Discoverer database tier, containing data and metadata (for more information, see Section 1.8, "About the Discoverer database tier").

Notes:

• For more information about configuring Discoverer on multiple machines, see Section 5.1, "Installing Oracle9iAS Discoverer in a multiple machine environment".

1.6 About the Discoverer client tier

The Discoverer client tier is the Internet browser accessing Discoverer Plus or Discoverer Viewer. To run Discoverer Plus and Discoverer Viewer, you must provide end users with the appropriate URL (for more information, see Section 3.1, "Running Oracle9iAS Discoverer").

1.6.1 About the Discoverer client tier and Discoverer Plus

For Discoverer Plus, the only requirement for the client machine is that it runs a Java-enabled Web browser (e.g. Microsoft Internet Explorer version 5 or later, or Netscape Navigator version 4.7 or later, both with Oracle JInitiator).

The first time that a machine is used to connect to Discoverer, the Discoverer Plus applet is downloaded from the Discoverer Services tier and cached on the client machine. The Discoverer Plus applet provides the Discoverer Plus user interface and functionality for analyzing business intelligence data. When the user logs on subsequently, the Discoverer Plus applet runs from the local cache and does not need to be downloaded.

Note: If you upgrade Discoverer, users might have to download the Discoverer Plus applet again to Discoverer client machines (for more information, see Section 3.1, "Running Oracle9iAS Discoverer".

1.6.2 About the Discoverer client tier and Discoverer Viewer

For Discoverer Viewer, the minimum requirement for the client machine is that it can run HTML through a web browser (e.g. Microsoft Internet Explorer (version 5 or later), or Netscape Navigator (version 4.7 or later)). To make use of the JavaScript enhanced user interface (e.g. drag and drop), both JavaScript and cookies must be enabled in the browser.

1.7 About the Discoverer Services tier

The Discoverer Services tier is the portion of the Discoverer architecture that the Discoverer middle tier manager installs and maintains.

Figure 1-4 Discoverer Services tier

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The Discoverer Services tier consists of:

• The Discoverer J2EE components (for more information, see Section 1.7.1, "About the Discoverer J2EE components")

• The Discoverer CORBA components (for more information, see Section 1.7.2, "About the Discoverer CORBA components")

Notes:

• The Discoverer Services tier also stores the Discoverer Plus applet, which is downloaded to client machines.

• All machines running the Discoverer middle tier components must be on the same subnet.

1.7.1 About the Discoverer J2EE components

The Discoverer J2EE components comprise the following:

• the Discoverer servlet (for more information, see Section 1.7.1.1, "What is the Discoverer servlet?")

• the Discoverer Plus servlet (for more information, see Section 1.7.1.2, "What is the Discoverer Plus servlet?")

• the Discoverer Portlet Provider servlet (for more information, see Section 1.7.1.3, "What is the Discoverer Portlet Provider servlet?")

Figure 1-5 Discoverer J2EE components

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A servlet comprises modules of Java code that run on a server machine to answer requests from client machines. Using a servlet minimizes client-side processing.

The Discoverer servlets are deployed into the OC4J (Oracle Components for Java) environment, which includes a servlet engine to run servlets.

1.7.1.1 What is the Discoverer servlet?

The Discoverer servlet generates HTML pages from HTTP requests using an XML/XSL processor.

1.7.1.2 What is the Discoverer Plus servlet?

The Discoverer Plus servlet provides the connection pages for Discoverer Plus and Discoverer Viewer.

The Discoverer Plus servlet forwards requests from the Discoverer Plus applet to the Discoverer servlet. The Discoverer Plus servlet adds a URL parameter to the request indicating that the Discoverer Plus applet was the originator of the request.

1.7.1.3 What is the Discoverer Portlet Provider servlet?

The Discoverer Portlet Provider servlet provides a user interface for publishing Discoverer worksheets and links to Discoverer workbooks on an Oracle9iAS Portal page. For more information about Discoverer Portlet Provider, see Section 11.1, "Using Discoverer with Oracle9iAS Portal".

1.7.2 About the Discoverer CORBA components

CORBA (Common Object Request Broker Architecture) components are responsible for activating Discoverer when an end user starts a Discoverer session (i.e. when a user connects to Discoverer Plus or Discoverer Viewer).

The Discoverer CORBA components comprise the following:

• the Discoverer Session component (for more information, see Section 1.7.2.1, "What is the Discoverer Session component?")

• the Discoverer Preferences component (for more information, see Section 1.7.2.2, "What is the Discoverer Preferences component?")

• the Object Activation Daemon (OAD) and SmartAgent - these are third party Visibroker CORBA components (supplied by Inprise) that are installed with Discoverer (for more information, see Section 1.7.2.3, "What is the Object Activation Daemon?")

Figure 1-6 Discoverer CORBA components

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1.7.2.1 What is the Discoverer Session component?

The Discoverer Session component (also referred to as a CORBA server) performs Discoverer operations such as connecting to the database or opening a workbook. The Discoverer Session component provides the link between the Discoverer servlet or applet and the database. There is one Discoverer Session component per active User Login session.

Figure 1-7 OAD, Preferences component, and Session components in a single machine Oracle9iAS install

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1.7.2.2 What is the Discoverer Preferences component?

The Discoverer Preferences component provides a single location for preference settings for all Oracle9iAS Discoverer users (i.e. users of both Discoverer Plus and Discoverer Viewer). The Discoverer Services tier relies on stored preference settings to specify the default Discoverer behavior.

Note: In a multiple machine environment with different Discoverer Session components running on different machines, Discoverer uses a single Preferences component on one machine.

1.7.2.3 What is the Object Activation Daemon?

The Object Activation Daemon (OAD) is a background process that runs and manages Discoverer Session components.

The OAD is installed on each Oracle9iAS machine. A machine on which the OAD component has been installed can run multiple concurrent Discoverer Session components, each supporting a single User Login session.

In a multiple machine environment (i.e. where you install Oracle9iAS on multiple application server machines), one OAD runs on each machine. Each machine can support multiple concurrent User Login Sessions and multiple Discoverer Session components. This configuration typically improves Discoverer performance and reliability.

1.8 About the Discoverer database tier

The database tier of the Discoverer architecture contains data and metadata.

Figure 1-8 Discoverer database tier

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The Discoverer database tier consists of:

• the Discoverer workbooks used to store reports and charts

• the End User Layer (EUL) that provides an easy-to-understand view of the data

• the business intelligence data that users want to analyze

You use Discoverer Administrator to create and maintain the EUL. For more information, see the Discoverer9i Administrator Administration Guide available with Oracle9iDS.

Notes:

• Before users can use Discoverer to analyze data, the database must contain a Discoverer EUL Version 5.1. You must create or update the EUL with Oracle9i Discoverer Administrator Version 9.0.2 or later (shipped as part of Oracle9i Developer Suite).

1.9 How does Oracle9iAS Discoverer work?

This section provides information about how Discoverer Plus and Discoverer Viewer work.

1.9.1 How does Discoverer Plus work?

Figure 1-9 The Discoverer Plus Process

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1. The user launches a Web browser on a client computer and types the URL of the Discoverer Plus servlet.

2. The Web browser accesses the Discoverer Plus servlet on the Application Server, which forwards the request to the Discoverer servlet.

3. The Discoverer servlet retrieves the Connection html page and returns this to the Discoverer Plus servlet, which in turn returns the page to the client.

4. The user selects a connection, which is returned to the Application Server and forwarded by the Discoverer Plus servlet to the Discoverer servlet.

5. The Discoverer applet is transmitted to the client computer (if it is not present already).

6. Meanwhile, the Discoverer servlet uses OAD to access the Session component on the Application Server machine and a Discoverer session starts.

7. The Discoverer session requests and receives data from the database.

8. The Discoverer session transmits data to the Discoverer servlet, which forwards it to the Discoverer Plus servlet which in turn forwards it to the client machine.

1.9.2 How does Discoverer Viewer work?

Figure 1-10 The Discoverer Viewer Process

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1. The user launches a Web browser on a client computer and types the URL of the Discoverer servlet.

2. The Web browser accesses the Discoverer servlet on the Application Server.

3. The Discoverer servlet retrieves the Connection html page and returns this to the client.

4. The user selects a connection, which is returned to the Discoverer servlet on the Application Server.

5. The Discoverer servlet uses OAD to access the Session component on the Application Server machine and a Discoverer session starts.

6. The Discoverer session requests and receives data from the database.

7. The Discoverer session transmits data to the Discoverer servlet, which generates an HTML page and forwards it to the client machine.