Oracle Essentials Oracle Database 11g (6 page)

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can use Oracle Net over a wide variety of network protocols, although TCP/IP is by far the most common protocol today. Features associated with Oracle Net, such as shared servers, are referred to as Oracle Net Services.

Oracle Internet Directory

The Oracle Internet Directory (OID) was introduced with Oracle8
i
. OID replaced Oracle Names used in prior database releases since it gives users a way to connect to an Oracle Server without having a client-side configuration file. OID is an LDAP

(Lightweight Directory Access Protocol) directory and so it supports Oracle Net and other LDAP-enabled protocols.

Oracle Connection Manager

Each connection to the database takes up valuable network resources, which can impact the overall performance of a database application. Oracle’s Connection Manager (CMAN), illustrated in
Figure 1-3,
reduces the number of Oracle Net client network connections to the database through the use of
concentrators
, which provide connection multiplexing to implement multiple connections over a single network connection. Connection multiplexing provides the greatest benefit when there are a large number of active users.

Database Server

Connection Managers

Clients

Figure 1-3. Concentrators with Connection Managers for a large number of users
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Chapter 1: Introducing Oracle

You can also use the Connection Manager to provide multiprotocol connectivity if youstill have some clients and servers not using TCP/IP. Oracle Database 10
g
introduced dynamic Connection Manager configuration, enabling the changing of CMAN

parameters without shutting down the CMAN process.

Oracle Application Server

The popularity of Internet and intranet applications led to a change in deployment from client/server (with fat clients running a significant piece of the application) to a three-tier architecture (with a browser supplying everything needed for a thin client).

Oracle Application Server enables deployment of the middle tier in a three-tier solution for web-based applications, component-based applications, and enterprise application integration. Oracle Application Server is a key part of Oracle’s Fusion Middleware and can be scaled across multiple middle-tier servers.

This product includes a web listener based on the popular Apache listener, servlets and JavaServer Pages (JSPs), business logic, and/or data access components. Business logic often is deployed as Enterprise JavaBeans (EJBs). Data access components can include JDBC, SQLJ, and EJBs. TopLink provides a mapping tool that links Java objects to the database via JDBC such that the Java developer need not build SQL

calls and or face broken Java applications resulting from database schema changes.

Oracle Application Server offers additional solutions in the cache, portal, business intelligence, and wireless areas:

Cache

Oracle Application Server Web Cache introduced a middle tier for the caching of web pages or portions of pages. An earlier cache, Oracle Application Server Database Cache, was used for caching PL/SQL procedures and anonymous PL/SQL

blocks but is no longer supported as of Oracle Application Server 10
g
.

Portal

Oracle Application Server Portal is also a part of the Oracle Developer Suite (discussed later in this chapter) and is used for building easy-to-use enterprise dashboards. The developed portal is deployed to the Application Server.

Business Intelligence

Application Server Business Intelligence components include the Portal as well as Oracle’s original business intelligence tools:

• Oracle Reports, which provides a scalable middle tier for the reporting of prebuilt query results

• Oracle Discoverer, for ad hoc query and analysis

• A deployment platform for JDeveloper custom-built OLAP and data mining applications

These capabilities are discussed in Chapter 10.

Database Connection Features

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Oracle Wireless

Oracle Wireless (formerly known as Oracle Portal-to-Go) includes:

• Content adapters for transforming content to XML

• Device transformers for transforming XML to device-specific markup languages

• Personalization portals for service personalization of alerts, alert addresses, location marks, and profiles; wireless personalization portal also used for the creation, servicing, testing, and publishing of URL service and for user management

Oracle Application Server is packaged in several editions: Enterprise Edition, Standard Edition, Standard Edition One, and Java Edition, which includes key components for Java developers. Portal, TopLink with the Application Development Framework, and the Web Cache are included in the Standard Edition and in Standard Edition One. The Enterprise Edition adds the following capabilities: Forms Services, Reports Services, Discoverer Viewer, Oracle Internet Directory, Oracle Application Interconnect, Wireless Option, and integration with Enterprise Service Bus (ESB). The Java Edition bundle includes an HTTP Server, OC4J, and TopLink with the Application Development Framework. We provide more details about Ora-

cle Application Server in Chapter 15.

Oracle Application Server Enterprise Edition has several available options including:
BPEL Process Manager Option

Oracle’s Business Process Execution Language (BPEL) tool is designed for Service-Oriented Architecture (SOA) environments and used for creating, managing, and deploying cross-application business processes. It supports standards such as BPEL, Web Services, XML, XSLT, XPATH, JMS, and JCA.

Business Activity Monitoring (BAM)

BAM is used for building real-time dashboards displaying key performance indicators (KPIs) populated with data from alerts monitored via the Web.

BI Publisher

A publishing and report layout tool used in generating high-fidelity reports from XML data.

Service Registry

The Oracle Service Registry enables publishing and advertising of services and provides a System of Record for SOA services.

SOA Suite for Oracle Middleware

The Suite bundles Oracle Fusion Middleware SOA offerings, including BPEL, BAM, business rules engine, Enterprise Service Bus (for messaging, routing, and transformations), Web Services Management (including a policy manager and monitoring dashboard), Web Services Registry, and applications and technology adapters.

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Chapter 1: Introducing Oracle

Communication and Mobility Server

This bundle includes TimesTen, and also provides a SIP Servlet Container, enabler framework and enablers, voice access, and mobile access.

WebCenter

WebCenter is Oracle’s latest portal framework used for deploying portlets and Ajax-based components, especially in Web 2.0 environments. It includes discussion forums, presence server, instant message client, Wiki, VOIP call setup and teardown, SIP Servlet Container, Java and Web Service APIs, Click-2-dial integration, and voice-enabled soft client.

Fusion Middleware Adapters

Adapters include Applications, Transaction Processing Monitors, EDI, and others.

The Fusion Middleware SOA Suite serves as the basis for Oracle’s Application Integration Architecture (AIA). AIA also includes prepackaged business objects and business processes known as Process Integration Packs and provides key underpin-nings used in integrating Oracle’s current and future applications.

Distributed Database Features

The Oracle database is well known for its ability to handle extremely large volumes of data and users. Oracle not only scales through deployment on increasingly powerful single platforms, but also can be deployed in distributed configurations. Oracle deployed on multiple platforms can be combined to act as a single logical distributed database.

This section describes some of the basic ways that Oracle handles database interactions in a distributed database system.

Distributed Queries and Transactions

Data within an organization is often spread among multiple databases for reasons of both capacity and organizational responsibility. Users may want to query this distributed data or update it as if it existed within a single database.

Oracle first introduced distributed databases in response to the requirements for accessing data on multiple platforms in the early 1980s.
Distributed queries
can retrieve data from multiple databases.
Distributed transactions
can insert, update, or delete data on distributed databases. Oracle’s two-phase commit mechanism, described in
Chapter 13,
guarantees that all the database servers that are part of a transaction will either commit or roll back the transaction. Background recovery processes can ensure database consistency in the event of system interruption during distributed transactions. Once the failed system comes back online, the same process will complete the distributed transactions.

Distributed Database Features

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Distributed transactions can also be implemented using popular transaction monitors (TPs) that interact with Oracle via XA, an industry-standard (X/Open) interface.

Oracle8
i
added native transaction coordination with the Microsoft Transaction Server (MTS), so you can implement a distributed transaction initiated under the control of MTS through an Oracle database.

Heterogeneous Services

Heterogeneous Services allow non-Oracle data and services to be accessed from an Oracle database through generic connectivity via ODBC and OLE-DB included with the database.

Optional Transparent Gateways use agents specifically tailored for a variety of target systems. Transparent Gateways allow users to submit Oracle SQL statements to a non-Oracle distributed database source and have them automatically translated into the SQL dialect of the non-Oracle source system, which remains transparent to the user. In addition to providing underlying SQL services, Heterogeneous Services provide transaction services utilizing Oracle’s two-phase commit with non-Oracle databases and procedural services that call third-generation language routines on non-Oracle systems. Users interact with the Oracle database as if all objects are stored in the Oracle database, and Heterogeneous Services handle the transparent interaction with the foreign database on the user’s behalf.

Data Movement Features

Moving data from one Oracle database to another is often a requirement when using distributed databases, or when a user wants to implement multiple copies of the same database in multiple locations to reduce network traffic or increase data availability. Youcan export data and data dictionaries (metadata) from one database and import them into another. Oracle Database 10
g
introduced a high-speed data pump for the import and export.

Oracle also offers many other advanced features in this category, including transportable tablespaces, Advanced Queuing/Oracle Streams, and extraction, transformation and loading (ETL) solutions. We introduce these next.

Transportable Tablespaces

Transportable tablespaces first appeared in Oracle8
i
. Instead of using the export/

import process, which dumps data and the structures that contain it into an intermediate file for loading, youcan place a tablespace in read-only mode, move or copy it from one database to another, and then mount it. The same data dictionary (metadata) describing the tablespace must exist on the source and the target. This feature can save a lot of time since it simplifies the movement of large amounts of data.

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Chapter 1: Introducing Oracle

Starting with Oracle Database 10
g
, youcan move data with transportable tablespaces between heterogeneous platforms or operating systems.

Advanced Queuing and Oracle Streams

Advanced Queuing (AQ), first introduced in Oracle8, provides the means to asynchronously send messages from one Oracle database to another. Because messages are stored in a queue in the database and sent asynchronously when a connection is made, the amount of overhead and network traffic is much lower than it would be using traditional guaranteed delivery through the two-phase commit protocol between source and target. By storing the messages in the database, AQ provides a solution with greater recoverability than other queuing solutions that store messages in filesystems.

Oracle messaging adds the capability to develop and deploy a
content
-
based publish
and subscribe solution
using a rules engine to determine relevant subscribing applications. As new content is published to a subscriber list, the rules on the list determine which subscribers should receive the content. This approach means that a single list can efficiently serve the needs of different subscriber communities. In the first release of Oracle9
i
, AQ added XML support and Oracle Internet Directory (OID) integration.

As of the second release of Oracle9
i
, AQ became part of Oracle Streams. Streams has three major components: log-based replication for data capture, queuing for data staging, and user-defined rules for data consumption. Since Oracle Database 10
g
, Streams also includes support for change data capture and file transfer solutions.

Streams is managed through Oracle Enterprise Manager and described in more detail

in Chapter 13.

Extraction, Transformation, and Loading

Oracle Warehouse Builder (OWB) is a tool used in the design of target databases, especially data warehouses, and provides a metadata repository. However, it is best known as a GUI-based tool used in building source-to-target maps and for generating extraction, transformation, and loading (ETL) scripts. OWB leverages key embedded ETL features in the Oracle database first made available in Oracle9
i
.