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{{Infobox Software
| name = Oracle Database
| logo = [[Image:Oracle logo.svg|200px]]
| screenshot =
| caption =
| developer = [[Oracle Corporation]]
| released = 1979
| latest_release_version = 11g
| latest_release_date = [[11 July]] [[2007]]
| latest_preview_version =
| latest_preview_date =
| release_location = Equitable Auditorium, 787 Seventh Avenue, New York, NY 10019
| operating system = [[Cross-platform]] ([[#Host platforms|List]])
| programming language = [[C_(programming language)|C]]
| language = [[#Languages|Multiple languages]]
| genre = [[Relational database management system|RDBMS]]
| license = [[Proprietary]]
| website = http://www.oracle.com/
}}
The [[relational database management system]] (RDBMS) officially called '''Oracle Database''' (and commonly referred to as '''Oracle RDBMS''' or simply as '''Oracle''') has become a major presence in [[database]] [[computing]]. [[Oracle Corporation]] produces and markets this software.

[[Larry Ellison]] and his friends and former co-workers [[Bob Miner]] and [[Ed Oates]] started the consultancy Software Development Laboratories (SDL) in 1977. SDL developed the original version of the Oracle software. The name ''Oracle'' comes from the code-name of a [[Central Intelligence Agency|CIA]]-funded project Ellison had worked on while previously employed by [[Ampex]].

Many widespread computing platforms have come to use the Oracle database software extensively.

== Physical and logical structuring ==
An Oracle database system comprises at least one instance of the application, along with data storage. An instance comprises a set of operating-system [[process (computing)|processes]] and [[memory (computers)|memory]]-structures that interact with the [[Computer storage|storage]]. Typical processes include PMON (the process monitor) and SMON (the system monitor).

Users of Oracle databases refer to the server-side memory-structure as the SGA (System Global Area). The SGA typically holds [[cache]] information such as data-buffers, [[SQL]] commands and user information. In addition to storage, the database consists of online redo logs (which hold [[Database transaction|transactional]] history). Processes can in turn [[archive]] the online redo logs into archive logs (offline redo logs), which provide the basis (if necessary) for [[data recovery]] and for some forms of [[data replication]].

The Oracle RDBMS stores data [[physical and logical storage|logically]] in the form of [[tablespace]]s and physically in the form of data [[Computer file|file]]s. Tablespaces can contain various types of [[memory segment]]s; for example, Data Segments, Index Segments etc. Segments in turn comprise one or more extents. Extents comprise groups of contiguous data blocks. Data blocks form the basic units of data storage. At the physical level, data-files comprise one or more data blocks, where the [[Block size (data storage and transmission)|block size]] can vary between data-files.

Oracle database management keeps track of its [[computer data storage]] with the help of information stored in the <code>SYSTEM</code> tablespace. The <code>SYSTEM</code> tablespace contains the [[data dictionary]] — and often (by default) [[Index (database)|index]]es and [[cluster]]s. (A data dictionary consists of a special collection of [[table (database)|table]]s that contains information about all user-[[object (computer science)|object]]s in the database). Since version 8i, the Oracle RDBMS also supports "locally managed" tablespaces which can store space management information in bitmaps in their own [[header]]s rather than in the <code>SYSTEM</code> tablespace (as happens with the default "dictionary-managed" tablespaces).

If the Oracle [[database administrator]] has instituted [[Oracle RAC]] (Real Application Clusters), then multiple instances, usually on different [[Server (computing)|server]]s, attach to a central [[Disk array|storage array]]. This scenario offers numerous advantages, most importantly performance, scalability and redundancy. However, support becomes more complex, and many sites do not use RAC. In version 10g, [[grid computing]] has introduced shared resources where an instance can use (for example) [[central processing unit|CPU]] resources from another node (computer) in the grid.

The Oracle DBMS can store and execute [[stored procedure]]s and [[function (programming)|function]]s within itself. [[PL/SQL]] (Oracle Corporation's proprietary procedural extension to [[SQL]]), or the object-oriented language [[Java (programming language)|Java]] can invoke such code objects and/or provide the programming structures for writing them.

=== [[Database schema]] ===

Oracle database conventions refer to defined groups of ownership (generally associated with a "username") as ''schemas''.

Most Oracle database installations traditionally come with a default schema called <code>SCOTT</code>. After the installation process has set up the sample tables, the user can log into the database with the username <code>scott</code> and the password <code>tiger</code>. The name of the <code>SCOTT</code> schema originated with Bruce Scott, one of the first employees at Oracle (then Software Development Laboratories), who had a cat named Tiger<ref>[http://www.orafaq.com/faqora.htm#SCOTT Oracle FAQ]</ref>.

The <code>SCOTT</code> schema has seen less use as it uses so few of the features of a modern release of Oracle. Most recent examples reference the default HR or OE schemas.

Other default schemas<ref>[http://www.adp-gmbh.ch/ora/misc/known_schemas.html Known schemas in Oracle]</ref> include:

* <code>SYS<code> (essential core database structures and utilities)
* <code>SYSTEM<code> (additional core database structures and utilities, and privileged account)
* <code>OUTLN</code> (utilized to store metadata for stored outlines for stable query-optimizer execution plans <ref>[http://www.adp-gmbh.ch/ora/tuning/cbo/plan_stability.html Optimizer plan stability definition]</ref>.
* <code>BI</code>, <code>IX</code>, <code>HR</code>, <code>OE</code>, <code>PM</code>, and <code>SH</code> (expanded sample schemas<ref>[http://www.adp-gmbh.ch/ora/misc/sample_schemas.html Oracle's sample schemas]</ref> containing more data and structures than the older <code>SCOTT</code> schema)

=== [[Tablespace]]s ===

Default tablespaces include:
* <code>SYSTEM</code> (essential core database structures and utilities)
* <code>SYSAUX</code> (extra/extended data to supplement the <code>SYSTEM</code> schema)
* <code>TEMP<code> (temporary tablespace)
* <code>UNDOTBS1<code> (undo tablespace)
* <code>USERS</code> (default users tablespace created by the Database Configuration Assistant - but replaceable by the DBA)

=== Memory architecture ===
==== System Global Area ====
{{main|System Global Area}}

Each Oracle instance uses a [[System Global Area]] or SGA &mdash; a [[shared memory|shared-memory]] area &mdash; to store its data and control-information. <ref>[http://www.world-class-programme.com/Oracle-Architecture-2.asp Oracle Architecture, System Global Area]</ref>

Each Oracle instance allocates itself an SGA when it starts and de-allocates it at shut-down time. The information in the SGA consists of the following elements, each of which has a fixed size, established at instance startup:

* the database buffer cache: this stores the most recently-used data blocks. These blocks can contain modified data not yet written to disk (sometimes known as "dirty blocks"), unmodified blocks, or blocks written to disk since modification (sometimes known as clean blocks). Because the buffer cache keeps blocks based on a most-recently-used algorithm, the most active buffers stay in memory to reduce I/O and to improve performance.
* the redo log buffer: this stores redo entries — a log of changes made to the database. The instance writes redo log buffers to the redo log as quickly and efficiently as possible. The redo log aids in instance recovery in the event of a system failure.
* the shared pool: this area of the SGA stores shared-memory structures such as shared SQL areas in the library cache and internal information in the data dictionary. An insufficient amount of memory allocated to the shared pool can cause performance degradation.

==== Library cache ====

The library cache<ref>[http://www.world-class-programme.com/Oracle-Architecture-2.asp Oracle architecture, the library cache section]</ref> stores shared SQL, caching the parse tree and the execution plan for every unique SQL statement.

If multiple applications issue the same SQL statement, each application can access the shared SQL area. This reduces the amount of memory needed and reduces the processing-time used for parsing and execution planning.

==== Data dictionary cache ====

The [[data dictionary]] comprises a set of tables and views that map the structure of the database.

Oracle stores information here about the logical and physical structure of the database. The data dictionary contains information such as the following:

* User information, such as user privileges
* Integrity constraints defined for tables in the database
* Names and datatypes of all columns in database tables
* Information on space allocated and used for schema objects

The Oracle instance frequently accesses the data dictionary in order to [[parsing|parse]] SQL statements. The operation of Oracle depends on ready access to the data dictionary: performance bottlenecks in the data dictionary affect all Oracle users. Because of this, database administrators should make sure that the data dictionary cache<ref>[http://www.world-class-programme.com/Oracle-Architecture-2.asp Oracle Architecture, data dictionary cache]</ref> has sufficient capacity to cache this data. Without enough memory for the data-dictionary cache, users see a severe performance degradation. Allocating sufficient memory to the shared pool where the data dictionary cache resides precludes these particular performance problems.

==== Program Global Area ====

The Program Global Area<ref>[http://www.world-class-programme.com/Oracle-Architecture-2.asp Oracle architecture, Program Global Area section]</ref> or PGA memory-area contains data and control-information for Oracle's server-processes.

The size and content of the PGA depends on the Oracle-server options installed. This area consists of the following components:

* stack-space: the memory that holds the session's variables, arrays, and so on.
* session-information: unless using the multithreaded server, the instance stores its session-information in the PGA. (In a multithreaded server, the session-information goes in the SGA.)
* private SQL-area: an area in the PGA which holds information such as bind-variables and runtime-buffers.
* sorting area: an area in the PGA which holds information on sorts, hash-joins, etc.

=== Process architecture ===

The Oracle RDBMS typically relies on a group of processes running simultaneously in the [[Background (computer software) | background]] and interacting to further and monitor database operations. Such processes (and their standard abbreviations) can include:<ref>
[http://download.oracle.com/docs/cd/B28359_01/server.111/b28318/process.htm#i16977 Oracle Process architecture concepts]
</ref>

* archiver processes (ARCn)
* checkpoint process (CKPT)
* database writer processes (DBWn)
* dispatcher processes (Dnnn): multiplex server-processes on behalf of users
* memory-manager process (MMAN): used for internal database tasks such as Automatic Shared Memory Management
* job-queue processes (CJQn)
* log-writer process (LGWR)
* log-write network-server (LNSn): transmits redo logs in Data Guard environments
* logical standby coordinator process (LSP0): controls [[Oracle Data Guard| Data Guard]] log-application
* media-recovery process (MRP): detached recovery-server process
* memory-monitor process (MMON)
* memory-monitor light process (MMNL): gathers and stores Automatic Workload Repository (AWR) data
* process-monitor process (PMON)
* process-spawner (PSP0): spawns Oracle processes
* queue-monitor processes (QMNn)
* recoverer process (RECO)
* remote file-server process (RFS)
* shared server processes (Snnn): serve client-requests
* system monitor process (SMON)

== Languages ==
Oracle Database software comes in 63 language-versions (including regional variations such as American and British). Variations between versions cover the names of days and months, abbreviations, time-symbols such as A.M. and A.D., and sorting<ref name="titleLocale Data">{{cite web |url=http://download.oracle.com/docs/cd/B19306_01/server.102/b14225/applocaledata.htm#i634428 |title=Locale Languages |accessdate=2008-02-26 |}}</ref>.

Oracle Corporation has translated Oracle Database error-messages into Arabic, Catalan, Chinese, Czech, Danish, Dutch, Finnish, French, German, Greek, Hebrew, Hungarian, Italian, Japanese, Korean, Norwegian, Polish, Portuguese, Romanian, Russian, Slovak, Spanish, Swedish, Thai and Turkish.<ref name="titleMessages Data">{{cite web |url=http://download.oracle.com/docs/cd/B19306_01/server.102/b14225/applocaledata.htm#i634673
|title=Error Message languagues |accessdate=2008-02-26 |}}
</ref>
<!-- could not find list of documentation translations yet-->

== History ==
=== Corporate/technical timeline ===
{{proseline}}

* 1979: [[Larry Ellison]] and friends founded Software Development Laboratories.
* 1979: SDL changed its company-name to "Relational Software, Inc." (RSI) and introduced its product Oracle V2 as an early commercially-available relational database system. The version did not support [[database transaction|transaction]]s, but implemented the basic [[SQL]] functionality of [[query|queries]] and [[join (SQL)|join]]s. (RSI never released a version 1 - instead calling the first version ''version 2'' as a [[marketing strategies|marketing gimmick]].)<ref>As Larry Ellison said in an Oracle OpenWorld keynote [http://www.news.com/8301-10784_3-9814858-7.html presentation] on [[2007-11-11]]: "Who'd buy a version 1.0 from four guys in California?"</ref>
* 1982: RSI in its turn changed its name, becoming known as "[[Oracle Corporation]]",<ref>http://www.oracle.com/oramag/profit/07-may/p27anniv_timeline.pdf</ref> to align itself more closely with its flagship-product.
* 1983: The company released Oracle version 3, which it had re-written using the [[C (programming language)|C programming language]] and which supported <code>[[Commit (data management)|COMMIT]]</code> and <code>[[Rollback (data management)|ROLLBACK]]</code> functionality for transactions. Version 3 extended platform support from the existing [[Digital Equipment Corporation|Digital]] [[VAX/VMS]] systems to include [[Unix]] environments.<ref>http://www.oracle.com/oramag/profit/07-may/p27anniv_timeline.pdf</ref>
* 1984: Oracle Corporation released Oracle version 4, which supported [[consistency model|read-consistency]].
* 1985: the Oracle RDBMS began supporting the [[client-server]] model, with networks becoming more widely available in the mid-1980s. Oracle version 5.0 supported [[distributed computing|distributed]] queries.
* 1988: Oracle RDBMS version 6 came out with support for [[PL SQL|PL/SQL]] embedded within Oracle Forms v3 (version 6 could not store PL/SQL in the database proper), row-level [[lock (computer science)|lock]]ing and hot [[backup]]s.<ref> Compare http://www.oracle.com/oramag/profit/07-may/p27anniv_timeline.pdf </ref>
* 1989: Oracle Corporation entered the [[application software|application product]]s market and developed its [[Enterprise resource planning|ERP]] product, (later to become part of the [[Oracle E-Business Suite]]), based on the Oracle relational database.
* 1990: the release of [[Oracle Applications]] release 8<ref>http://www.oracle.com/oramag/profit/07-may/p27anniv_timeline.pdf</ref>
* 1992: Oracle version 7 appeared with support for [[referential integrity]], [[stored procedure]]s and [[database trigger|trigger]]s.
* 1997: Oracle Corporation released version 8, which supported [[object orientation|object-oriented]] development and [[multimedia]] applications.
* 1999: The release of Oracle8i aimed to provide a database inter-operating better with the [[Internet]] (the ''i'' in the name stands for "Internet"). The Oracle 8i database incorporated a native [[Java virtual machine]] ([[Oracle JVM]]).
* 2000: Oracle E-Business Suite 11i pioneers integrated enterprise application software<ref>http://www.oracle.com/oramag/profit/07-may/p27anniv_timeline.pdf</ref>
* 2001: Oracle9i went into release with 400 new features, including the ability to read and write [[XML]] documents. 9i also provided an option for [[Oracle RAC]], or "Real Application Clusters", a [[computer cluster|computer-cluster]] database, as a replacement for the Oracle Parallel Server (OPS) option.
* 2003: Oracle Corporation released Oracle Database 10g. (The ''g'' stands for "grid"; emphasizing a marketing thrust of presenting 10g as "grid-computing ready".)
* 2005: Oracle Database 10.2.0.1 &mdash; also known as Oracle Database 10g Release 2 (10gR2) &mdash; appeared.
* 2006: Oracle Corporation announces [[Unbreakable Linux]]<ref>http://www.oracle.com/oramag/profit/07-may/p27anniv_timeline.pdf</ref>
* 2007: Oracle Database 10g Release 2 Sets New [[World Record]] TPC-H 300 GB [[Benchmark]] Result<ref>{{cite web |url=http://www.itmanagement.com/press-releases/oracle-tpc-h-record-060806/ |title=Oracle Database 10g Sets New Record for TPC-H Three TB Benchmark |accessdate=2008-01-31 |format= |work= }}</ref>
* 2007: Oracle Corporation released Oracle Database 11g for [[Linux]] and for [[Microsoft Windows]].
* 2008: Oracle Corporation acquires BEA Web systems.

=== Version-numbering ===

Oracle products have historically followed their own release-numbering and naming conventions. With the Oracle RDBMS 10g release, Oracle Corporation started standardizing all current versions of its major products using the "10g" label, although some sources continued to refer to Oracle Applications Release 11i as ''Oracle 11i''. Major database-related products and some of their versions include:

* [[Oracle Application Server]] 10g (also known as "Oracle AS 10g"): a [[middleware]] product;
* [[Oracle Applications]] Release 11i (aka Oracle e-Business Suite, Oracle Financials or Oracle 11i): a [[software suite|suite]] of [[business]] applications;
* [[Oracle Developer Suite]] 10g (9.0.4);
* [[Oracle JDeveloper]] 10g: a [[Java (programming language)|Java]] [[integrated development environment]];

Since version 7, Oracle's [[Relational database management system|RDBMS]] release numbering has used the following codes:

* Oracle7: 7.0.16 — 7.3.4
* Oracle8 Database: 8.0.3 — 8.0.6
* Oracle8i Database Release 1: 8.1.5.0 — 8.1.5.1
* Oracle8i Database Release 2: 8.1.6.0 — 8.1.6.3
* Oracle8i Database Release 3: 8.1.7.0 — 8.1.7.4
* Oracle9i Database Release 1: 9.0.1.0 — 9.0.1.5 (Latest current patchset as of December 2003)
* Oracle9i Database Release 2: 9.2.0.1 — 9.2.0.8 (Latest current [[Patch (computing)|patchset]] [[as of 2007|as of April 2007]])
* Oracle Database 10g Release 1: 10.1.0.2 — 10.1.0.5 (Latest current patchset [[as of 2006|as of February 2006]])
* Oracle Database 10g Release 2: 10.2.0.1 — 10.2.0.3 (Latest current patchset [[as of 2006|as of November 2006]])
* Oracle Database 11g Release 1: 11.1.0.6 — no patchset available [[as of 2007|as of October 2007]]

The version numbering syntax within each release follows the pattern: major.maintenance.application-server.component-specific.platform-specific.
For example, "10.2.0.1 for 64-bit Solaris" means: 10th major version of Oracle, maintenance level 2, Oracle Application Server (OracleAS) 0, level 1 for Solaris 64-bit.

The ''Oracle Administrator's Guide'' offers further information on Oracle release numbers. Oracle Corporation provides a table<ref>[http://www.oracle.com/technology/support/patches.htm Oracle Database Patch Sets]</ref> showing the latest patch-set releases by major release, operating-system, and hardware-architecture.

=== List of claimed firsts ===

{{Refimprove|date=December 2007}}

Oracle Corporation claims to have provided:

* the first commercially-available [[SQL]]-based database (1979)<ref>Greenwald, R., Stackowiak R., & Stern, J. (2001). Oracle Essentials: Oracle9i, Oracle8i & Oracle8 (2nd edition). Cambridge, MA: O'Reilly.</ref>
* the first database to support [[symmetric multiprocessing]] (SMP) (1983)
* the first [[distributed database]] (1986)
* the first database product tested to comply with the [[SQL#Standardization|ANSI SQL standard]] (1993)<ref>Greenwald, R., Stackowiak R., & Stern, J. (2001). Oracle Essentials: Oracle9i, Oracle8i & Oracle8 (2nd edition). Cambridge, MA: O'Reilly.</ref>
* the first [[64-bit]] database (1995)
* the first [[web database]] (1997)
* the first database to incorporate a native [[Java Runtime Environment|JRE]] (1998)
* the first proprietary [[Relational database management system|RDBMS]] to become available on [[Linux]] (1998)<ref>http://www.oracle.com/technologies/open-source/docs/oracle-opensource-ds.pdf; but compare Informix's claim to priority: http://www.linuxjournal.com/article/3110, retrieved [[2008-02-13]]</ref>
* the first database to support [[XML]] (1999)

== Editions ==

Over and above the different versions of the Oracle database management software, Oracle Corporation subdivides its product into varying "editions" - apparently for marketing and license-tracking reasons. In approximate order of decreasing scale, we find:

* '''Enterprise Edition<ref>[http://www.oracle.com/database/enterprise_edition.html Enterprise Edition]</ref>''' (EE) includes more features than the 'Standard Edition', especially in the areas of performance and security. Oracle Corporation licenses this product on the basis of users or of processors, typically for servers running 4 or more CPUs. EE has no memory limits, and can utilize clustering using [[Oracle RAC]] software.
* '''Standard Edition<ref>[http://www.oracle.com/database/standard_edition.html Standard Edition]</ref>''' (SE) contains base database functionality. Oracle Corporation licenses this product on the basis of users or of processors, typically for servers running from one to four CPUs. If the number of CPUs exceeds 4 CPUs, the user must convert to an Enterprise license. SE has no memory limits, and can utilize clustering with [[Oracle RAC]] at no additional charge.
* '''Standard Edition One<ref>[http://www.oracle.com/database/std_one.html Standard Edition One]</ref>''', introduced with Oracle 10g, has some additional feature-restrictions. Oracle Corporation markets it for use on systems with one or two CPUs. It has no memory limitations.
* '''Express Edition<ref>[http://www.oracle.com/technology/products/database/xe/index.html Express Edition]</ref>''' ('Oracle Database XE'), introduced in 2005, offers Oracle 10g free to distribute on Windows and Linux platforms (with a footprint of only 150 MB and restricted to the use of a single CPU, a maximum of 4 GB of user data and 1 GB of memory). Support for this version comes exclusively through on-line forums and not through Oracle support.
* '''Oracle Personal Edition<ref>[http://www.oracle.com/database/Personal_Edition.html Oracle Personal Edition]</ref>''' provides the functionality of the "high end" Enterprise Edition but marketed to (and licensed for) single-user developers working on personal [[workstation]]s.
* '''[http://www.oracle.com/database/lite_edition.html Oracle Database Lite]''', intended to run on [[mobile device]]s. The [[database]], partially located on the mobile device, can synchronize with a server-based installation.

== Host platforms ==

Prior to releasing Oracle9i, Oracle Corporation ported the database engine to a wide variety of platforms. More recently, Oracle Corporation has consolidated on a smaller range of operating system platforms.

[[As of 2006#October|As of October 2006]], Oracle Corporation supported the following operating systems and hardware platforms for Oracle Database 10g:

* [[Apple Computer|Apple]] [[Mac OS X Server]]: [[PowerPC]]
* [[Hewlett-Packard|HP]] [[HP-UX]]: [[PA-RISC]], [[Itanium]]
* HP [[Tru64|Tru64 UNIX]]: [[DEC Alpha|Alpha]]
* HP [[OpenVMS]]: Alpha, Itanium
* [[IBM]] [[IBM AIX (operating system)|AIX5L]]: [[IBM POWER]]
* IBM [[z/OS]]: [[zSeries]]
* [[Linux]]: [[x86]], [[x86-64]], PowerPC, zSeries, Itanium
* [[Microsoft]] [[Microsoft Windows|Windows]]: x86, x86-64, Itanium
* [[Sun Microsystems|Sun]] [[Solaris (operating system)|Solaris]]: [[SPARC]], x86, x86-64

== Related software ==

For links to some of Oracle Corporation's software which integrates with Oracle databases, see the [[:Category:Oracle Corporation|Oracle Corporation category]] and the [[:Category:Oracle software|Oracle software category]] pages.

=== Database options ===

Oracle Corporation refers to some extensions to the core functionality of the Oracle database as "database options".<ref>
[http://www.oracle.com/database/database-options.html Oracle database options]
</ref>
[[As of 2008]] such options include:

* [http://www.oracle.com/database/in-memory-database-cache.html In-Memory Database Cache]
* [http://www.oracle.com/database/active-data-guard.html Active Data Guard]
* [http://www.oracle.com/database/advanced-security.html Advanced Security]
* [http://www.oracle.com/database/contentdb.html Content database]
* [http://www.oracle.com/database/database-vault.html Database Vault]
* [http://www.oracle.com/database/total-recall.html Total Recall]
* [http://www.oracle.com/technology/products/bi/odm/index.html Data Mining] (ODM)
* [http://www.oracle.com/database/label-security.html Label Security]
* [http://www.oracle.com/technology/products/oem/extensions/index.html Management Packs] (various)
* [http://www.oracle.com/appserver/business-intelligence/standard-edition-one.html Oracle Answers]
* [http://www.oracle.com/solutions/business_intelligence/olap.html Oracle OLAP]
* [http://www.oracle.com/technology/products/oracle9i/datasheets/partitioning.html Partitioning]
* [[Oracle RAC|Real Application Clusters]] (RAC)
* [http://www.oracle.com/database/recordsdb.html Records database]
* [[Oracle Spatial]]
* [[Oracle Warehouse Builder]] (in various forms and sub-options)
* [[Oracle Real Application Testing]]
{{expand_list}}

In most cases, using these options entails extra licensing costs.

=== Suites ===

In addition to its [[Relational database management system|RDBMS]], Oracle Corporation has released several related suites of tools and applications relating to implementations of Oracle databases. For example:

* [[Oracle Application Server]], a J2EE-based [[application server]], aids in developing and deploying applications which utilise [[Internet]] technologies and a browser.
* [[Oracle Collaboration Suite]] contains messaging, groupware and collaboration applications.
* [[Oracle Developer Suite]] contains software development tools, including [[JDeveloper]].
* [[Oracle E-Business Suite]] collects together applications for [[enterprise resource planning]] (including [[Oracle Financials]]), [[customer relationship management]] and [[human resources]] management ([[Oracle HR]]).
* [[Oracle Enterprise Manager]] (OEM) used by [[database administrator]]s (DBAs) to manage the DBMS, and [[as of 2007 | recently]] in version 10g, a web-based rewrite of OEM called "Oracle Enterprise Manager Database Control". Oracle Corporation has dubbed the super-Enterprise-Manager used to manage a grid of multiple DBMS and Application Servers "Oracle Enterprise Manager Grid Control".

=== Database "features" ===

Apart from the clearly-defined database options, Oracle databases may include many semi-autonomous software sub-systems, which Oracle Corporation sometimes refers to as "features" in a sense subtly different from the normal usage of the word.<ref>
For example, [[Oracle Data Guard]] counts officially as a "feature", but the command-stack within SQL*Plus, though a usability feature, does not appear in the list of "features" in http://download.oracle.com/docs/cd/B19306_01/license.102/b14199/editions.htm#CJACGHEB
</ref>
Such "features" may include (for example):

* [http://www.oracle.com/technology/pub/articles/10gdba/week6_10gdba.html Automatic Workload Repository (AWR)], providing monitoring services to Oracle database installations from Oracle version 10. Prior to the release of Oracle version 10, the Statspack facility provided similar functionality.
* Clusterware
* [http://www.oracle.com/solutions/business_intelligence/warehouse-builder.html Data Aggregation and Consolidation]
* [http://www.oracle.com/technology/deploy/availability/htdocs/DataGuardOverview.html Data Guard] for [[high availability]]
* Data Pump utilities, which aid in importing and exporting data and metadata between databases.<ref>[http://download.oracle.com/docs/cd/B28359_01/server.111/b28319/dp_overview.htm#SUTIL100 Overview of Oracle Data Pump<!-- Bot generated title -->]</ref>
* [[Oracle Flashback | Flashback]] for selective data recovery and reconstruction<ref>http://www.oracle.com/technology/deploy/availability/htdocs/Flashback_Overview.htm</ref>
* [http://www.oracle.com/technology/tech/sql_plus/index.html iSQL*Plus], a web-browser-based [[graphical user interface]] (GUI) for Oracle database [[Data Manipulation Language| data-manipulation]] (compare SQL*Plus)
* [http://download.oracle.com/docs/cd/B28359_01/server.111/b28310/omf.htm#i1007206 Oracle-managed files] (OMF) -- a feature allowing automated naming, creation and deletion of datafiles at the operating-system level.
* [http://web.archive.org/web/20051208092120/http://www.oracle.com/technology/deploy/availability/htdocs/rman_overview.htm Recovery Manager] (rman) for [[database dump|database backup]], [[restoration]] and [[data recovery|recovery]]
* [[SQL*Plus]], a program that allows users to interact with Oracle database(s) via [[SQL]] and [[PL/SQL]] commands on a [[command line interface| command-line]]. Compare iSQL*Plus.
{{expand_list}}

=== Standalone tools ===

Various tools address specific environments or specific market requirements.

Development of applications commonly takes place in Java (using Oracle JDeveloper) or through PL/SQL (using, for example, [[Oracle Forms]] and [[Oracle Reports]]). Oracle Corporation has started <!-- when ? --> a drive toward 'wizard'-driven environments with a view to enabling non-programmers to produce simple data-driven applications.

[[Oracle SQL Developer]], a free graphical tool for database development, allows developers to browse database objects, run SQL statements and SQL scripts, and edit and debug PL/SQL statements. It incorporates standard and customized reporting.

A list of some of the binaries and scripts supplied by Oracle Corporation to operate with/alongside Oracle databases and associated software appears on the [http://www.rootshell.be/~yong321/computer/oraclebin.html Oracle executables] web-page.

=== Database-related guidelines ===

Oracle Corporation also endorses certain practices and conventions as enhancing the use of its database products. These include:

* [http://search.techrepublic.com.com/search/Oracle+Maximum+Availability+Architecture.html Oracle Maximum Availability Architecture (MAA)], guidelines on developing high-availability systems
* [http://download-east.oracle.com/docs/html/B14399_01/app_ofa.htm Optimal Flexible Architecture (OFA)], blueprints for mapping Oracle-database objects to file-systems

=== Other databases marketed by Oracle Corporation ===

* [[TimesTen]], a memory-resident database that has the ability to cache [[transaction]]s and synchronize data with a centralized Oracle database server. It functions as a [[real-time computing|real-time]] infrastructure software product intended for the management of low-[[lag|latency]], high-volume data, of events and of [[transaction]]s.
* [[BerkeleyDB]], a simple, high-performance, [[Embedded Database | embedded database]]

== Using Oracle Database software ==

Users of Oracle databases may access the [http://www.oracle.com/technology/documentation online documentation], the Oracle Technology Network site, and the comp.databases.oracle [[Usenet]] discussion group. The Oracle [http://www.oracle.com/technology Technet] site offers downloads of full-featured evaluation software. Users who have Oracle support contracts should turn to Oracle's [http://metalink.oracle.com Metalink] web site (password required). Users can also check the [http://www.orafaq.com/ Oracle FAQ] site before posting questions to forums, mailing lists, etc. They can also log on to http://asktom.oracle.com to post questions to and get answers from [[Thomas Kyte|Tom Kyte]], a Vice-President of Oracle Corporation and the author of several Oracle books including ''Expert One-On-One Oracle'' (ISBN 1-59059-525-4).

The Oracle RDBMS has had a reputation among novice users as difficult to install on Linux systems. Oracle Corporation has packaged [[as of 2006|recent]] versions for several popular Linux distributions in an attempt to minimize installation challenges beyond the level of technical expertise required to install a database server. {{Fact|date=February 2007}}

== Oracle Database in the market ==
=== Competition ===

In the market for relational databases, Oracle competes against commercial products such as IBM's [[IBM DB2|DB2]] UDB and [[Microsoft SQL Server]]. Oracle and IBM tend to battle for the mid-range database market on UNIX and Linux platforms, while Microsoft dominates the mid-range database market on [[Microsoft Windows]] platforms. However, since they share many of the same customers, Oracle and IBM tend to support each other's products in many middleware and application categories (for example, [[WebSphere]], [[PeopleSoft]], and [[Siebel Systems]] [[Customer relationship management|CRM]]), and IBM's hardware divisions work closely with Oracle on performance-optimizing server-technologies (for example, Linux on zSeries). The two companies have a relationship perhaps best described as "[[coopetition]]". Niche commercial competitors include [[Teradata]] (in data warehousing and business intelligence), Software AG's [[ADABAS]], [[Sybase]], and IBM's [[Informix]], among many others.

Increasingly, the Oracle database products compete against [[open source|open-source]] relational database systems, particularly [[PostgreSQL]], [[Firebird (database server)|Firebird]], and [[MySQL]]. Oracle acquired [[Innobase]], supplier of the [[InnoDB]] codebase to MySQL, in part to compete better in the open source market. Database products developed on the basis of the open-source model generally cost significantly less to acquire than Oracle systems.

[[As of 2007|Recently]], competition with [[SAP AG]] software has occasioned litigation from Oracle Corporation<ref>[http://hirek.prim.hu/cikk/61917/ About the case] in Hungarian</ref>.

=== Pricing ===

Oracle Corporation offers term licensing for all Oracle products. It bases the list price for a term-license on a specific percentage of the perpetual license price.<ref>See the published [http://www.oracle.com/corporate/pricing/technology-price-list.pdf price list].</ref>
[[As of 2006|As of March 2006]], the "Enterprise Edition" of the Oracle database costs the most per machine-processor among Oracle database engines. Standard Edition comes cheaper: it can run on up to 4 processors but has fewer features than Enterprise Edition — it lacks proper parallelization,{{Fact|date=May 2007}} etc; but remains quite suitable for running medium-sized applications). Standard ONE edition sells even more cheaply, but remains limited to 2 CPUs. Standard Edition ONE sells on a per-seat basis with a 5-user minimum. Oracle Corporation usually sells the licenses with an extra 22% cost for support and upgrades (access to MetaLink - Oracle Corporation's support site) which customers need to renew annually.
Oracle Express Edition (Oracle XE), an addition to the Oracle database product family ([[development stage#Beta|beta]] version released in 2005, production version released in February 2006), offers a free version of the Oracle RDBMS, but one limited to 4 GB of user data and to 1 GB of RAM. XE will use no more than one CPU and lacks an internal [[Java virtual machine|JVM]].
As computers running Oracle often have eight or more processors, the software price can rise into the hundreds of thousands of dollars. The [[total cost of ownership]] exceeds this, as Oracle databases usually require experienced and trained [[database administrator]]s to do the set-up properly. Because of the product's large installed base and available training courses, Oracle specialists in some areas have become a more abundant resource than those for more exotic databases. Oracle frequently provides special training offers for database-administrators.
On Linux, Oracle's ''certified configurations'' include mostly commercial [[Linux distributions]] (RedHat Enterprise Linux 3 and 4, [[SUSE Linux Enterprise Server|SuSE SLES8]] and 9, [[Asianux]]) which can cost in a range from a few hundred to a few thousand USD per year (depending on processor architecture and the support package purchased). One can avoid paying for those [[Linux distribution | distro]]s by using free alternatives such as any [[Red Hat Enterprise Linux clones]] (such as [[CentOS]] or [[White Box Linux]]). Oracle also runs reliably on unsupported distributions.

== See also ==

* [[List of relational database management systems]]
* [[List of object-relational database management systems]]
* [[Comparison of relational database management systems]]
* [[Comparison of object-relational database management systems]]
* [[Oracle Rdb]] for [[OpenVMS]]
* [[List of ERP software packages]]
* [[Run Book Automation]]

== References ==

{{reflist}}

== External links ==

* [http://www.oracle.com/technology/software/products/database/oracle10g/ Oracle Database], a view provided by Oracle Corporation
* [http://docs.oracle.com On-line documentation]
* [http://www.psoug.org/library.html On-line demos]
* [http://metalink.oracle.com Metalink, Oracle Corporation's online support site] (requires a password)
* [http://asktom.oracle.com Ask Tom]: Oracle-related questions addressed by [[Thomas Kyte]]
* [http://forums.oracle.com/forums/index.jspa?categoryID=1 OTN]: Oracle support website
* [http://www.orafaq.com OraFAQ]: an unofficial website for users of the Oracle Database
* [http://www.spviewer.com Oracle Performance Tuning using STATSPACK/AWR]: a site presenting a set of performance tuning tools and techniques for Oracle databases using STATSPACK/AWR Oracle built-in technologies

{{Databases}}

[[Category:Database management systems]]
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[[Category:Oracle software]]

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Revision as of 01:03, 24 April 2008

Oracle Database
Developer(s)Oracle Corporation
Initial release1979
Stable release
Written inC
Operating systemCross-platform (List)
Available inMultiple languages
TypeRDBMS
LicenseProprietary
Websitehttp://www.oracle.com/

The relational database management system (RDBMS) officially called Oracle Database (and commonly referred to as Oracle RDBMS or simply as Oracle) has become a major presence in database computing. Oracle Corporation produces and markets this software.

Larry Ellison and his friends and former co-workers Bob Miner and Ed Oates started the consultancy Software Development Laboratories (SDL) in 1977. SDL developed the original version of the Oracle software. The name Oracle comes from the code-name of a CIA-funded project Ellison had worked on while previously employed by Ampex.

Many widespread computing platforms have come to use the Oracle database software extensively.

Physical and logical structuring

An Oracle database system comprises at least one instance of the application, along with data storage. An instance comprises a set of operating-system processes and memory-structures that interact with the storage. Typical processes include PMON (the process monitor) and SMON (the system monitor).

Users of Oracle databases refer to the server-side memory-structure as the SGA (System Global Area). The SGA typically holds cache information such as data-buffers, SQL commands and user information. In addition to storage, the database consists of online redo logs (which hold transactional history). Processes can in turn archive the online redo logs into archive logs (offline redo logs), which provide the basis (if necessary) for data recovery and for some forms of data replication.

The Oracle RDBMS stores data logically in the form of tablespaces and physically in the form of data files. Tablespaces can contain various types of memory segments; for example, Data Segments, Index Segments etc. Segments in turn comprise one or more extents. Extents comprise groups of contiguous data blocks. Data blocks form the basic units of data storage. At the physical level, data-files comprise one or more data blocks, where the block size can vary between data-files.

Oracle database management keeps track of its computer data storage with the help of information stored in the SYSTEM tablespace. The SYSTEM tablespace contains the data dictionary — and often (by default) indexes and clusters. (A data dictionary consists of a special collection of tables that contains information about all user-objects in the database). Since version 8i, the Oracle RDBMS also supports "locally managed" tablespaces which can store space management information in bitmaps in their own headers rather than in the SYSTEM tablespace (as happens with the default "dictionary-managed" tablespaces).

If the Oracle database administrator has instituted Oracle RAC (Real Application Clusters), then multiple instances, usually on different servers, attach to a central storage array. This scenario offers numerous advantages, most importantly performance, scalability and redundancy. However, support becomes more complex, and many sites do not use RAC. In version 10g, grid computing has introduced shared resources where an instance can use (for example) CPU resources from another node (computer) in the grid.

The Oracle DBMS can store and execute stored procedures and functions within itself. PL/SQL (Oracle Corporation's proprietary procedural extension to SQL), or the object-oriented language Java can invoke such code objects and/or provide the programming structures for writing them.

Database schema

Oracle database conventions refer to defined groups of ownership (generally associated with a "username") as schemas.

Most Oracle database installations traditionally come with a default schema called SCOTT. After the installation process has set up the sample tables, the user can log into the database with the username scott and the password tiger. The name of the SCOTT schema originated with Bruce Scott, one of the first employees at Oracle (then Software Development Laboratories), who had a cat named Tiger[1].

The SCOTT schema has seen less use as it uses so few of the features of a modern release of Oracle. Most recent examples reference the default HR or OE schemas.

Other default schemas[2] include:

  • SYS (essential core database structures and utilities)
  • SYSTEM (additional core database structures and utilities, and privileged account)
  • OUTLN (utilized to store metadata for stored outlines for stable query-optimizer execution plans [3].
  • BI, IX, HR, OE, PM, and SH (expanded sample schemas[4] containing more data and structures than the older SCOTT schema)

Tablespaces

Default tablespaces include:

  • SYSTEM (essential core database structures and utilities)
  • SYSAUX (extra/extended data to supplement the SYSTEM schema)
  • TEMP (temporary tablespace)
  • UNDOTBS1 (undo tablespace)
  • USERS (default users tablespace created by the Database Configuration Assistant - but replaceable by the DBA)

Memory architecture

System Global Area

Main article: System Global Area

Each Oracle instance uses a System Global Area or SGA — a shared-memory area — to store its data and control-information. [5]

Each Oracle instance allocates itself an SGA when it starts and de-allocates it at shut-down time. The information in the SGA consists of the following elements, each of which has a fixed size, established at instance startup:

  • the database buffer cache: this stores the most recently-used data blocks. These blocks can contain modified data not yet written to disk (sometimes known as "dirty blocks"), unmodified blocks, or blocks written to disk since modification (sometimes known as clean blocks). Because the buffer cache keeps blocks based on a most-recently-used algorithm, the most active buffers stay in memory to reduce I/O and to improve performance.
  • the redo log buffer: this stores redo entries — a log of changes made to the database. The instance writes redo log buffers to the redo log as quickly and efficiently as possible. The redo log aids in instance recovery in the event of a system failure.
  • the shared pool: this area of the SGA stores shared-memory structures such as shared SQL areas in the library cache and internal information in the data dictionary. An insufficient amount of memory allocated to the shared pool can cause performance degradation.

Library cache

The library cache[6] stores shared SQL, caching the parse tree and the execution plan for every unique SQL statement.

If multiple applications issue the same SQL statement, each application can access the shared SQL area. This reduces the amount of memory needed and reduces the processing-time used for parsing and execution planning.

Data dictionary cache

The data dictionary comprises a set of tables and views that map the structure of the database.

Oracle stores information here about the logical and physical structure of the database. The data dictionary contains information such as the following:

  • User information, such as user privileges
  • Integrity constraints defined for tables in the database
  • Names and datatypes of all columns in database tables
  • Information on space allocated and used for schema objects

The Oracle instance frequently accesses the data dictionary in order to parse SQL statements. The operation of Oracle depends on ready access to the data dictionary: performance bottlenecks in the data dictionary affect all Oracle users. Because of this, database administrators should make sure that the data dictionary cache[7] has sufficient capacity to cache this data. Without enough memory for the data-dictionary cache, users see a severe performance degradation. Allocating sufficient memory to the shared pool where the data dictionary cache resides precludes these particular performance problems.

Program Global Area

The Program Global Area[8] or PGA memory-area contains data and control-information for Oracle's server-processes.

The size and content of the PGA depends on the Oracle-server options installed. This area consists of the following components:

  • stack-space: the memory that holds the session's variables, arrays, and so on.
  • session-information: unless using the multithreaded server, the instance stores its session-information in the PGA. (In a multithreaded server, the session-information goes in the SGA.)
  • private SQL-area: an area in the PGA which holds information such as bind-variables and runtime-buffers.
  • sorting area: an area in the PGA which holds information on sorts, hash-joins, etc.

Process architecture

The Oracle RDBMS typically relies on a group of processes running simultaneously in the background and interacting to further and monitor database operations. Such processes (and their standard abbreviations) can include:[9]

  • archiver processes (ARCn)
  • checkpoint process (CKPT)
  • database writer processes (DBWn)
  • dispatcher processes (Dnnn): multiplex server-processes on behalf of users
  • memory-manager process (MMAN): used for internal database tasks such as Automatic Shared Memory Management
  • job-queue processes (CJQn)
  • log-writer process (LGWR)
  • log-write network-server (LNSn): transmits redo logs in Data Guard environments
  • logical standby coordinator process (LSP0): controls Data Guard log-application
  • media-recovery process (MRP): detached recovery-server process
  • memory-monitor process (MMON)
  • memory-monitor light process (MMNL): gathers and stores Automatic Workload Repository (AWR) data
  • process-monitor process (PMON)
  • process-spawner (PSP0): spawns Oracle processes
  • queue-monitor processes (QMNn)
  • recoverer process (RECO)
  • remote file-server process (RFS)
  • shared server processes (Snnn): serve client-requests
  • system monitor process (SMON)

Languages

Oracle Database software comes in 63 language-versions (including regional variations such as American and British). Variations between versions cover the names of days and months, abbreviations, time-symbols such as A.M. and A.D., and sorting[10].

Oracle Corporation has translated Oracle Database error-messages into Arabic, Catalan, Chinese, Czech, Danish, Dutch, Finnish, French, German, Greek, Hebrew, Hungarian, Italian, Japanese, Korean, Norwegian, Polish, Portuguese, Romanian, Russian, Slovak, Spanish, Swedish, Thai and Turkish.[11]

History

Corporate/technical timeline

  • 1979: Larry Ellison and friends founded Software Development Laboratories.
  • 1979: SDL changed its company-name to "Relational Software, Inc." (RSI) and introduced its product Oracle V2 as an early commercially-available relational database system. The version did not support transactions, but implemented the basic SQL functionality of queries and joins. (RSI never released a version 1 - instead calling the first version version 2 as a marketing gimmick.)[12]
  • 1982: RSI in its turn changed its name, becoming known as "Oracle Corporation",[13] to align itself more closely with its flagship-product.
  • 1983: The company released Oracle version 3, which it had re-written using the C programming language and which supported COMMIT and ROLLBACK functionality for transactions. Version 3 extended platform support from the existing Digital VAX/VMS systems to include Unix environments.[14]
  • 1984: Oracle Corporation released Oracle version 4, which supported read-consistency.
  • 1985: the Oracle RDBMS began supporting the client-server model, with networks becoming more widely available in the mid-1980s. Oracle version 5.0 supported distributed queries.
  • 1988: Oracle RDBMS version 6 came out with support for PL/SQL embedded within Oracle Forms v3 (version 6 could not store PL/SQL in the database proper), row-level locking and hot backups.[15]
  • 1989: Oracle Corporation entered the application products market and developed its ERP product, (later to become part of the Oracle E-Business Suite), based on the Oracle relational database.
  • 1990: the release of Oracle Applications release 8[16]
  • 1992: Oracle version 7 appeared with support for referential integrity, stored procedures and triggers.
  • 1997: Oracle Corporation released version 8, which supported object-oriented development and multimedia applications.
  • 1999: The release of Oracle8i aimed to provide a database inter-operating better with the Internet (the i in the name stands for "Internet"). The Oracle 8i database incorporated a native Java virtual machine (Oracle JVM).
  • 2000: Oracle E-Business Suite 11i pioneers integrated enterprise application software[17]
  • 2001: Oracle9i went into release with 400 new features, including the ability to read and write XML documents. 9i also provided an option for Oracle RAC, or "Real Application Clusters", a computer-cluster database, as a replacement for the Oracle Parallel Server (OPS) option.
  • 2003: Oracle Corporation released Oracle Database 10g. (The g stands for "grid"; emphasizing a marketing thrust of presenting 10g as "grid-computing ready".)
  • 2005: Oracle Database 10.2.0.1 — also known as Oracle Database 10g Release 2 (10gR2) — appeared.
  • 2006: Oracle Corporation announces Unbreakable Linux[18]
  • 2007: Oracle Database 10g Release 2 Sets New World Record TPC-H 300 GB Benchmark Result[19]
  • 2007: Oracle Corporation released Oracle Database 11g for Linux and for Microsoft Windows.
  • 2008: Oracle Corporation acquires BEA Web systems.

Version-numbering

Oracle products have historically followed their own release-numbering and naming conventions. With the Oracle RDBMS 10g release, Oracle Corporation started standardizing all current versions of its major products using the "10g" label, although some sources continued to refer to Oracle Applications Release 11i as Oracle 11i. Major database-related products and some of their versions include:

Since version 7, Oracle's RDBMS release numbering has used the following codes:

  • Oracle7: 7.0.16 — 7.3.4
  • Oracle8 Database: 8.0.3 — 8.0.6
  • Oracle8i Database Release 1: 8.1.5.0 — 8.1.5.1
  • Oracle8i Database Release 2: 8.1.6.0 — 8.1.6.3
  • Oracle8i Database Release 3: 8.1.7.0 — 8.1.7.4
  • Oracle9i Database Release 1: 9.0.1.0 — 9.0.1.5 (Latest current patchset as of December 2003)
  • Oracle9i Database Release 2: 9.2.0.1 — 9.2.0.8 (Latest current patchset as of April 2007)
  • Oracle Database 10g Release 1: 10.1.0.2 — 10.1.0.5 (Latest current patchset as of February 2006)
  • Oracle Database 10g Release 2: 10.2.0.1 — 10.2.0.3 (Latest current patchset as of November 2006)
  • Oracle Database 11g Release 1: 11.1.0.6 — no patchset available as of October 2007

The version numbering syntax within each release follows the pattern: major.maintenance.application-server.component-specific.platform-specific.

For example, "10.2.0.1 for 64-bit Solaris" means: 10th major version of Oracle, maintenance level 2, Oracle Application Server (OracleAS) 0, level 1 for Solaris 64-bit.

The Oracle Administrator's Guide offers further information on Oracle release numbers. Oracle Corporation provides a table[20] showing the latest patch-set releases by major release, operating-system, and hardware-architecture.

List of claimed firsts

Oracle Corporation claims to have provided:

Editions

Over and above the different versions of the Oracle database management software, Oracle Corporation subdivides its product into varying "editions" - apparently for marketing and license-tracking reasons. In approximate order of decreasing scale, we find:

  • Enterprise Edition[24] (EE) includes more features than the 'Standard Edition', especially in the areas of performance and security. Oracle Corporation licenses this product on the basis of users or of processors, typically for servers running 4 or more CPUs. EE has no memory limits, and can utilize clustering using Oracle RAC software.
  • Standard Edition[25] (SE) contains base database functionality. Oracle Corporation licenses this product on the basis of users or of processors, typically for servers running from one to four CPUs. If the number of CPUs exceeds 4 CPUs, the user must convert to an Enterprise license. SE has no memory limits, and can utilize clustering with Oracle RAC at no additional charge.
  • Standard Edition One[26], introduced with Oracle 10g, has some additional feature-restrictions. Oracle Corporation markets it for use on systems with one or two CPUs. It has no memory limitations.
  • Express Edition[27] ('Oracle Database XE'), introduced in 2005, offers Oracle 10g free to distribute on Windows and Linux platforms (with a footprint of only 150 MB and restricted to the use of a single CPU, a maximum of 4 GB of user data and 1 GB of memory). Support for this version comes exclusively through on-line forums and not through Oracle support.
  • Oracle Personal Edition[28] provides the functionality of the "high end" Enterprise Edition but marketed to (and licensed for) single-user developers working on personal workstations.
  • Oracle Database Lite, intended to run on mobile devices. The database, partially located on the mobile device, can synchronize with a server-based installation.

Host platforms

Prior to releasing Oracle9i, Oracle Corporation ported the database engine to a wide variety of platforms. More recently, Oracle Corporation has consolidated on a smaller range of operating system platforms.

As of October 2006, Oracle Corporation supported the following operating systems and hardware platforms for Oracle Database 10g:

For links to some of Oracle Corporation's software which integrates with Oracle databases, see the Oracle Corporation category and the Oracle software category pages.

Database options

Oracle Corporation refers to some extensions to the core functionality of the Oracle database as "database options".[29] As of 2008 such options include:

In most cases, using these options entails extra licensing costs.

Suites

In addition to its RDBMS, Oracle Corporation has released several related suites of tools and applications relating to implementations of Oracle databases. For example:

Database "features"

Apart from the clearly-defined database options, Oracle databases may include many semi-autonomous software sub-systems, which Oracle Corporation sometimes refers to as "features" in a sense subtly different from the normal usage of the word.[30] Such "features" may include (for example):

Standalone tools

Various tools address specific environments or specific market requirements.

Development of applications commonly takes place in Java (using Oracle JDeveloper) or through PL/SQL (using, for example, Oracle Forms and Oracle Reports). Oracle Corporation has started a drive toward 'wizard'-driven environments with a view to enabling non-programmers to produce simple data-driven applications.

Oracle SQL Developer, a free graphical tool for database development, allows developers to browse database objects, run SQL statements and SQL scripts, and edit and debug PL/SQL statements. It incorporates standard and customized reporting.

A list of some of the binaries and scripts supplied by Oracle Corporation to operate with/alongside Oracle databases and associated software appears on the Oracle executables web-page.

Oracle Corporation also endorses certain practices and conventions as enhancing the use of its database products. These include:

Other databases marketed by Oracle Corporation

Using Oracle Database software

Users of Oracle databases may access the online documentation, the Oracle Technology Network site, and the comp.databases.oracle Usenet discussion group. The Oracle Technet site offers downloads of full-featured evaluation software. Users who have Oracle support contracts should turn to Oracle's Metalink web site (password required). Users can also check the Oracle FAQ site before posting questions to forums, mailing lists, etc. They can also log on to http://asktom.oracle.com to post questions to and get answers from Tom Kyte, a Vice-President of Oracle Corporation and the author of several Oracle books including Expert One-On-One Oracle (ISBN 1-59059-525-4).

The Oracle RDBMS has had a reputation among novice users as difficult to install on Linux systems. Oracle Corporation has packaged recent versions for several popular Linux distributions in an attempt to minimize installation challenges beyond the level of technical expertise required to install a database server. [citation needed]

Oracle Database in the market

Competition

In the market for relational databases, Oracle competes against commercial products such as IBM's DB2 UDB and Microsoft SQL Server. Oracle and IBM tend to battle for the mid-range database market on UNIX and Linux platforms, while Microsoft dominates the mid-range database market on Microsoft Windows platforms. However, since they share many of the same customers, Oracle and IBM tend to support each other's products in many middleware and application categories (for example, WebSphere, PeopleSoft, and Siebel Systems CRM), and IBM's hardware divisions work closely with Oracle on performance-optimizing server-technologies (for example, Linux on zSeries). The two companies have a relationship perhaps best described as "coopetition". Niche commercial competitors include Teradata (in data warehousing and business intelligence), Software AG's ADABAS, Sybase, and IBM's Informix, among many others.

Increasingly, the Oracle database products compete against open-source relational database systems, particularly PostgreSQL, Firebird, and MySQL. Oracle acquired Innobase, supplier of the InnoDB codebase to MySQL, in part to compete better in the open source market. Database products developed on the basis of the open-source model generally cost significantly less to acquire than Oracle systems.

Recently, competition with SAP AG software has occasioned litigation from Oracle Corporation[33].

Pricing

Oracle Corporation offers term licensing for all Oracle products. It bases the list price for a term-license on a specific percentage of the perpetual license price.[34] As of March 2006, the "Enterprise Edition" of the Oracle database costs the most per machine-processor among Oracle database engines. Standard Edition comes cheaper: it can run on up to 4 processors but has fewer features than Enterprise Edition — it lacks proper parallelization,[citation needed] etc; but remains quite suitable for running medium-sized applications). Standard ONE edition sells even more cheaply, but remains limited to 2 CPUs. Standard Edition ONE sells on a per-seat basis with a 5-user minimum. Oracle Corporation usually sells the licenses with an extra 22% cost for support and upgrades (access to MetaLink - Oracle Corporation's support site) which customers need to renew annually. Oracle Express Edition (Oracle XE), an addition to the Oracle database product family (beta version released in 2005, production version released in February 2006), offers a free version of the Oracle RDBMS, but one limited to 4 GB of user data and to 1 GB of RAM. XE will use no more than one CPU and lacks an internal JVM. As computers running Oracle often have eight or more processors, the software price can rise into the hundreds of thousands of dollars. The total cost of ownership exceeds this, as Oracle databases usually require experienced and trained database administrators to do the set-up properly. Because of the product's large installed base and available training courses, Oracle specialists in some areas have become a more abundant resource than those for more exotic databases. Oracle frequently provides special training offers for database-administrators. On Linux, Oracle's certified configurations include mostly commercial Linux distributions (RedHat Enterprise Linux 3 and 4, SuSE SLES8 and 9, Asianux) which can cost in a range from a few hundred to a few thousand USD per year (depending on processor architecture and the support package purchased). One can avoid paying for those distros by using free alternatives such as any Red Hat Enterprise Linux clones (such as CentOS or White Box Linux). Oracle also runs reliably on unsupported distributions.

See also

References

  1. ^ Oracle FAQ
  2. ^ Known schemas in Oracle
  3. ^ Optimizer plan stability definition
  4. ^ Oracle's sample schemas
  5. ^ Oracle Architecture, System Global Area
  6. ^ Oracle architecture, the library cache section
  7. ^ Oracle Architecture, data dictionary cache
  8. ^ Oracle architecture, Program Global Area section
  9. ^ Oracle Process architecture concepts
  10. ^ "Locale Languages". Retrieved 2008-02-26. {{cite web}}: Cite has empty unknown parameter: |1= (help)
  11. ^ "Error Message languagues". Retrieved 2008-02-26. {{cite web}}: Cite has empty unknown parameter: |1= (help)
  12. ^ As Larry Ellison said in an Oracle OpenWorld keynote presentation on 2007-11-11: "Who'd buy a version 1.0 from four guys in California?"
  13. ^ http://www.oracle.com/oramag/profit/07-may/p27anniv_timeline.pdf
  14. ^ http://www.oracle.com/oramag/profit/07-may/p27anniv_timeline.pdf
  15. ^ Compare http://www.oracle.com/oramag/profit/07-may/p27anniv_timeline.pdf
  16. ^ http://www.oracle.com/oramag/profit/07-may/p27anniv_timeline.pdf
  17. ^ http://www.oracle.com/oramag/profit/07-may/p27anniv_timeline.pdf
  18. ^ http://www.oracle.com/oramag/profit/07-may/p27anniv_timeline.pdf
  19. ^ "Oracle Database 10g Sets New Record for TPC-H Three TB Benchmark". Retrieved 2008-01-31.
  20. ^ Oracle Database Patch Sets
  21. ^ Greenwald, R., Stackowiak R., & Stern, J. (2001). Oracle Essentials: Oracle9i, Oracle8i & Oracle8 (2nd edition). Cambridge, MA: O'Reilly.
  22. ^ Greenwald, R., Stackowiak R., & Stern, J. (2001). Oracle Essentials: Oracle9i, Oracle8i & Oracle8 (2nd edition). Cambridge, MA: O'Reilly.
  23. ^ http://www.oracle.com/technologies/open-source/docs/oracle-opensource-ds.pdf; but compare Informix's claim to priority: http://www.linuxjournal.com/article/3110, retrieved 2008-02-13
  24. ^ Enterprise Edition
  25. ^ Standard Edition
  26. ^ Standard Edition One
  27. ^ Express Edition
  28. ^ Oracle Personal Edition
  29. ^ Oracle database options
  30. ^ For example, Oracle Data Guard counts officially as a "feature", but the command-stack within SQL*Plus, though a usability feature, does not appear in the list of "features" in http://download.oracle.com/docs/cd/B19306_01/license.102/b14199/editions.htm#CJACGHEB
  31. ^ Overview of Oracle Data Pump
  32. ^ http://www.oracle.com/technology/deploy/availability/htdocs/Flashback_Overview.htm
  33. ^ About the case in Hungarian
  34. ^ See the published price list.
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