UTF-8 encoding and UTF encoding provide support for more than 57 languages and character sets. Extensive localization is provided for example, for data formats , and customized localization can be added through the Oracle Locale Builder. Oracle includes a Globalization Toolkit for creating applications that will be used in multiple languages. The Internet and corporate intranets have created a growing demand for storage and manipulation of nontraditional datatypes within the database.
There is a need for extensions to the standard functionality of a database for storing and manipulating image, audio, video, spatial, and time series information. These capabilities are enabled through extensions to standard SQL. For more details regarding these features of Oracle, see Chapter Oracle Multimedia formerly interMedia provides text manipulation and additional image, audio, video, and locator functions in the database.
Oracle Multimedia offers the following major capabilities:. The text portion of Multimedia Oracle Text can identify the gist of a document by searching for themes and key phrases within the document.
The image portion of Multimedia can store and retrieve images of various formats; starting with Oracle Database 11 g , these include DICOM medical images. The audio and video portions of Multimedia can store and retrieve audio and video clips, respectively.
The locator portion of Multimedia can retrieve data that includes spatial coordinate information. Document retrieval is based on user access rights. In addition, Oracle offers an alternative Secure Enterprise Search offering that is more flexible in non-Oracle environments. It can optimize the display and retrieval of data linked to coordinates and is used in the development of spatial information systems.
Several vendors of Geographic Information Systems GIS products now bundle this option and leverage it as their search and retrieval engine. The connection between the client and the database server is a key component of the overall architecture. The database connection is responsible for supporting all communications between an application and the data it uses. Oracle includes a number of features that establish and tune your database connections, described in the following subsections.
Database users connect to the database by establishing a network connection. You can also link database servers via network connections. 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. Each connection to the database takes up valuable network resources, which can impact the overall performance of a database application.
Connection multiplexing provides the greatest benefit when there are a large number of active users. 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.
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:. Oracle Application Server Web Cache introduced a middle tier for the caching of web pages or portions of pages.
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. Oracle Reports, which provides a scalable middle tier for the reporting of prebuilt query results. These capabilities are discussed in Chapter Oracle Wireless formerly known as Oracle Portal-to-Go includes:.
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.
We provide more details about Oracle Application Server in Chapter BAM is used for building real-time dashboards displaying key performance indicators KPIs populated with data from alerts monitored via the Web. A publishing and report layout tool used in generating high-fidelity reports from XML data. This bundle includes TimesTen, and also provides a SIP Servlet Container, enabler framework and enablers, voice access, and mobile access.
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. 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 s. Distributed queries can retrieve data from multiple databases.
Distributed transactions can insert, update, or delete data on distributed databases. 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. 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. 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. 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.
You can 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. We introduce these next. Transportable tablespaces first appeared in Oracle8 i. 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.
Starting with Oracle Database 10 g , you can move data with transportable tablespaces between heterogeneous platforms or operating systems. 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. 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 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. We describe it further in Chapter Oracle Data Integrator is based on a product and company that Oracle acquired named Sunopsis. Oracle includes several features specifically designed to boost performance in certain situations. Database tasks implemented in parallel speed up querying, tuning, and maintenance of the database.
By breaking up a single task into smaller tasks and assigning each subtask to an independent process, you can dramatically improve the performance of certain types of database operations. Examples of query features implemented in parallel include:.
In addition to parallel query, many other Oracle features and capabilities are parallelized. Parallel operations are further identified and described in Chapter 7. While parallel features improve the overall performance of the Oracle database, Oracle also has particular performance enhancements for business intelligence and data warehousing applications.
We introduce many of them here, but see Chapter 10 for more detailed explanations of products and features specific to data warehousing and business intelligence. Oracle added support for stored bitmap indexes to Oracle 7. Bitmap indexes typically work best for columns that have few different values relative to the overall number of rows in a table. Bitmap indexes are described in more detail in Chapter 4.
Typical data warehousing queries occur against a large fact table with foreign keys to much smaller dimension tables. Oracle added an optimization for this type of star query in Oracle 7. Performance gains are realized through the use of Cartesian product joins of dimension tables with a single join back to the large fact table.
Oracle8 introduced a further mechanism called a parallel bitmap star join , which uses bitmap indexes on the foreign keys to the dimension tables to speed star joins involving a large number of dimension tables. Since Oracle8 i , materialized views have provided another means of achieving a significant speedup of query performance. Summary-level information derived from a fact table and grouped along dimension values is stored as a materialized view. Queries that can use this view are directed to the view, transparently to the user and the SQL they submit.
Oracle has continued to improve optimizer usage of materialized views with each new release of the database. A growing trend in Oracle and other databases is inclusion of SQL-accessible analytic and statistical functions in the database. Today, the functionality provided also includes ranking functions, windowing aggregate functions, lag and lead functions, reporting aggregate functions, statistical aggregates, linear regression, descriptive statistics, correlations, crosstabs, hypothesis testing, distribution fitting, and Pareto analysis.
As a result, any business intelligence tool that submits SQL to an Oracle database can transparently take advantage of the improved performance offered by deployment of this option. Refreshes of the values in these cubes are now maintained similar to refreshing materialized views.
Oracle data warehouses are often accessed using business intelligence tools from other popular vendors. Essbase is available as an option for providing an OLAP cube and functionality independently of the data warehouse database. Oracle also offers business intelligence applications that include data models and reporting and analysis with prepopulated business metadata. Oracle includes many features that make the database easier to manage. Ease in Oracle management fundamentally improved with the introduction of Oracle Database 10 g , and has continued to evolve toward being more self-tuning and self-managing with the release of Oracle Database 11 g.
If you are still managing Oracle databases using techniques such as scripts from previous releases and are moving to one of the newer releases, now is the time to reevaluate your thinking on management. Some of the newer fully automated features, such as Automatic Memory Management, also leverage data gathered in the AWR. Oracle has a near real-time view of current database conditions as it makes automated recommendations.
Such recommendations will often be more accurate than would be possible with the manual processes you might have used in the past. EM provides a database management tool framework and an HTML-based interface used to manage database users, instances, and features. New with Oracle Database 11 g is the Support Workbench and diagnosability infrastructure leveraged in reporting problems to Oracle Support.
Multiple database administrators can access the EM repository at the same time. Introduced in , Information Lifecycle Management ILM provides a means to define classes of data and storage tiers and move the data to the storage tiers that provide the right combination of performance and cost.
For more details, see Chapter 5. As every database administrator knows, backing up a database is a rather mundane but necessary task. An improper backup makes recovery difficult, if not impossible.
Unfortunately, people often realize the extreme importance of this everyday task only after losing business-critical data resulting from a failure of a related system. The following sections introduce some features used in performing database backup operations. We discuss backup and recovery strategies and options in much greater detail in Chapter Typical kinds of backups include complete database backups the most common type , tablespace backups, datafile backups, control file backups, and archivelog backups.
Oracle8 introduced the Recovery Manager RMAN for the server-managed backup and recovery of the database, leveraging a Recovery Catalog stored in the database. RMAN can automatically locate, back up, restore, and recover datafiles, control files, and archived redo logs.
Since Oracle9 i , RMAN can restart backups and restore and implement recovery window policies when backups expire. Oracle Enterprise Manager 10 g introduced an improved job scheduler that can be used with RMAN for managing automatic backups to disk.
RMAN can also perform point-in-time recovery, which allows the recovery of data until just prior to an undesirable event such as the mistaken dropping of a table. Optionally, Oracle offers an enterprise-class backup solution simply named Oracle Secure Backup. Database availability depends upon the reliability and management of the database, the underlying operating system, and the specific hardware components of the system.
Oracle has improved availability by reducing backup and recovery times by:. Oracle introduced partitioning as an option with Oracle8 to provide a higher degree of manageability and availability. You can take individual partitions offline for maintenance while other partitions remain available for user access. In data warehousing implementations, partitioning is sometimes used to implement rolling windows based on date ranges.
Other partitioning types include hash partitioning used to divide data into partitions using a hashing function and providing an even distribution of data and list partitioning enabling partitioning of data based on discrete values such as geography.
Starting with Oracle Database 11 g , interval partitioning can also be used to automatically create new fixed ranges as needed during data insertions. Examples of composite partitions in Oracle Database 11 g include range-range, range-hash, range-list, list-range, list-hash, and list-list. Oracle first introduced a standby database feature in Oracle 7. The standby database provides a copy of the production database to be used if the primary database is lost—for example, in the event of primary site failure or during routine maintenance.
Primary and standby databases may be geographically separated. The standby database is created from a copy of the production database and updated through the application of archived redo logs generated by the production database. Data Guard, first introduced in Oracle9 i , fully automates this process; previously, you had to manually copy and apply the logs. Agents are deployed on both the production and standby database, and a Data Guard Broker coordinates commands.
A single Data Guard command invokes the eight steps required for failover. In addition to providing physical standby database support, Data Guard can create a logical standby database. In this scenario, Oracle archive logs are transformed into SQL transactions and applied to an open standby database. Oracle Database 10 g introduced several new features, including support for real-time application of redo data, integration with the Flashback database feature, and archivelog compression.
Starting with Oracle Database 10 g , rolling upgrades are supported. As of Oracle Database 11 g , the Active Data Guard Opton enables the standby database to be used for queries, sorting, and reporting even as changes from the production system are being applied.
The Fail Safe feature provides a higher level of reliability for an Oracle database. Failover is implemented through a second system or node that provides access to data residing on a shared disk when the first system or node fails. Oracle Fail Safe for Windows, in combination with Microsoft Cluster Services, provides a failover solution in the event of a system failure.
Fail Safe is primarily a disaster recovery tool, so some downtime does occur as part of a failover operation. The recommended solution for server availability, since Oracle9 i , is Real Application Clusters. RAC can provide failover support as well as increased scalability on Unix, Linux, and Windows clusters.
Key to improved scalability was the introduction of Cache Fusion that greatly minimizes the amount of writing to disk that was formerly used to control data locks. With Real Application Clusters, you can deploy multiple Oracle instances on multiple nodes of a clustered solution or in a grid configuration.
RAC coordinates traffic among the systems or nodes, allowing the instances to function as a single database. As a result, the database has proven to scale across dozens of nodes. Since the cluster provides a means by which multiple instances can access the same data, the failure of a single instance will not cause extensive delays while the system recovers. Applications can leverage the Oracle Call Interface OCI to provide failover to a second instance transparently to the user.
Data Guard provides automated failover with bounded recovery time in conjunction with Oracle Real Application Clusters.
In addition, it provides client rerouting from the failed instance to the instance that is available with fast reconnect and automatically captures diagnostic data. Oracle Database 10 g introduced Automated Storage Management ASM , which provides optimum striping and mirroring of data for performance and availability. Because ASM is managed through Enterprise Manager, the database administrator now can perform this critical management task.
The need to coordinate this activity with a system administrator is thus greatly reduced. Oracle Database 11 g introduced the capability to rerun production workloads and test system changes through the Real Application Testing Option. Database Replay captures production workload information, including concurrency, dependencies, and timing. It transforms the workload capture files into replay files, provides a Replay Client for processing the replay files, and provides the means to report on performance statistics and any errors that might occur.
Oracle includes basic security for managing user access through roles and privileges. Database security features allow you to implement a Virtual Private Database VPD using Oracle by creating and attaching policies to database tables, views, or synonyms.
Many organizations face the need to meet more stringent compliance requirements for improved data protection, although database usage now can extend beyond organizational boundaries. Oracle has added several options to the database to enable secure deployment in such challenging environments.
Oracle Label Security controls access to data by comparing labels assigned to rows of data with label authorizations granted to users through their privileges. Multiple authorization levels are possible within a single database. Label security authorizations are managed through a Policy Manager. Policies are enforced in the database instead of through views, thus greatly simplifying management of data accessibility and providing a more secure implementation. Oracle Database Vault Option provides fine-grained access control to data for everyone with access to the database, including database administrators.
The security administrator can set factors to define access to the database and audit specific dimensions of security. At a more granular level, realms can be defined for limiting access to specific schemas and roles.
Oracle Audit Vault Server monitors database audit tables, redo logs, and operating system audit files for suspicious activities. It can then generate reports or send alerts showing where such unusual activity is occurring.
Many Oracle tools are available to developers to help them present data and build more sophisticated Oracle database applications.
Oracle JDeveloper was introduced by Oracle in to enable the development of basic Java applications without the need to write code. JDeveloper is now available for free and can be downloaded from the Oracle Technology Network.
Although JDeveloper uses wizards to allow programmers to create Java objects without writing code, the end result is generated Java code. SQL Developer can create connections to Oracle databases, browse database objects, create and modify database objects, query and update data, export data and DDL, import data, process commands, and run and create reports. In addition, SQL Developer can be pointed at non-Oracle databases to view their database objects and data, and it provides capabilities to begin a migration to an Oracle database.
Developer is a fourth-generation language 4GL. With a 4GL, you define applications by defining values for properties, rather than by writing procedural code.
Oracle Reports Developer provides a development and deployment environment for rapidly building and publishing web-based reports via Reports for Oracle Application Server. Data can be formatted in tables, matrices, group reports, graphs, and combinations.
Oracle Designer provides a graphical interface for Rapid Application Development RAD for the entire database development process—from building the business model to schema design, generation, and deployment.
Designs and changes are stored in a multiuser repository. The tool can reverse-engineer existing tables and database schemas for reuse and redesign from Oracle and non-Oracle relational databases. Designer can generate applications and reverse-engineer existing applications or applications that have been modified by developers.
This capability enables a process called round-trip engineering , in which a developer uses Designer to generate an application, modifies the generated application, and reverse-engineers the changes back into the Designer repository.
The purpose of this layer is to shield business analysts using Discoverer as an ad hoc query and analysis tool from SQL complexity. Wizards guide the administrator through the process of building the EUL. In addition, administrators can place limits on resources available to analysts monitored by the Discoverer query governor. Portal application systems are developed and deployed in a simple browser environment. Portals can be designed to be user-customizable and are deployed to the middle-tier Oracle Application Server.
Oracle Portal brought a key enhancement to WebDB, the ability to create and use portlets , which allow a single web page to be divided up into different areas that can independently display information and interact with the user. For example, Oracle Answers, Discoverer, and Reports can be accessed as portlets.
These database engines have unique code lines in order to provide small footprints and have different intended roles. For this reason, we will describe these briefly in the following subsections but will not explore their capabilities in great detail elsewhere in this book. Oracle TimesTen is a relational database that is stored in physical memory and is typically used where very high-performance transaction-processing workloads are present.
TimesTen databases can be deployed as exclusive or shared and can be created as permanent or temporary.
The database is refreshed by gathering data using TimesTen libraries deployed to applications or by using a Cache Connect option to an Oracle database. Because data is read and updated in memory, average update or read response times are typically measured in the millionths of seconds.
The Cache Connect option supports both read and write caching of Oracle database data. Updates can be bidirectional between TimesTen and Oracle. As is typical for embedded databases, TimesTen requires almost no ongoing administration. Replication is possible from one TimesTen database to another through an option and is, by default, asynchronous.
Oracle Berkeley DB is an extremely small-footprint embedded database engine providing record-level locking. It comes in Java and XML versions. It is designed to be deployed with and run in the same process as your applications. When Berkeley DB is deployed in this manner, no separate database administration is required.
Footprints for the database can be as small as KB. XQuery and XPath are supported. Both editions can be configured for high availability using replication. Automatic recovery is also supported. Deployment decisions such as these are made by the application designer at application design time.
Oracle Lite is a suite of products enabling mobile use of database-centric applications. ODBC is also supported. The Oracle Lite Database is also designed to be self-tuning and self-administering and is supported on handheld devices running Windows CE, Symbian, Windows, and Linux.
In typical usage of Oracle Lite, the user will link her handheld or mobile device running the Oracle Lite Database to a large-footprint Oracle Database Server.
Data is then automatically synchronized between the two systems. The user will then remove the link and work in disconnected mode. It contains chapters on:. Data is at the center of many challenges in system design today. Difficult issues need to …. To really learn data science, you should not only master the tools—data science libraries, frameworks, modules, …. Despite its wide availability and usage, few developers and DBAs have mastered the true power of …. Skip to main content. Start your free trial.
Buy on Amazon. Book description Oracle is an enormous system, with myriad technologies, options, and releases. It contains chapters on: Oracle products, options, data structures, and overall architecture for Oracle Database 11g, as well as earlier releases Oracle Database 10g, Oracle9i, and Oracle8i Installing, running, managing, monitoring, networking, and tuning Oracle, including Enterprise Manager EM and Oracle's self-tuning and management capabilities; and using Oracle security, auditing, and compliance a new chapter in this edition Multiuser concurrency, data warehouses, distributed databases, online transaction processing OLTP , high availability, and hardware architectures e.
But even if you already have a library full of Oracle documentation, you'll find that this compact book is the one you turn to, again and again, as your one-stop, truly essential reference. It's a great reference for anyone doing development or management of Oracle databases.
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