NationMaster - Encyclopedia: IBM DB2

DB2 is one of IBM's lines of relational database management system (or, as IBM now calls it, data server) software products within IBM's broader Information Management Software line. Although there are different "editions" and "versions" of DB2 which run on devices ranging from handhelds to mainframes, most often DB2 refers to DB2 Enterprise Server Edition or the top-of-the-line DB2 Data Warehouse Edition (DB2 DWE), which runs on Unix, Windows or Linux servers; or DB2 for z/OS. Beside DB2 there exists Informix, which was acquired by IBM in 2001. For other uses, see IBM (disambiguation) and Big Blue. ... A relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd. ... This article does not cite any references or sources. ... A handheld is most often used to refer to: A personal digital assistant (PDA). ... For other uses, see Mainframe. ... This article or section does not cite its references or sources. ... Filiation of Unix and Unix-like systems Unix (officially trademarked as UNIXÂ®, sometimes also written as or Â® with small caps) is a computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and Douglas McIlroy. ... 1. ... This article is about operating systems that use the Linux kernel. ... z/OS Welcome Screen seen through a terminal emulator The title of this article begins with a capital letter due to technical limitations. ... Informix is a family of relational database management system products from IBM, acquired in 2001 from a company (also called Informix or Informix Software) which dates its origins back to 1980. ...

History

DB2 has a long history and was what some consider to be the first database product to use SQL. SQL (IPA: or ) is a computer language designed for the retrieval and management of data in relational database management systems, database schema creation and modification, and database object access control management. ...

The name DB2 was first given to the Database Management System or DBMS in 1983 when IBM released DB2 on its MVS mainframe platform. Prior to this, a similar product was named SQL/DS on the VM mainframe. The earlier System 38 platform also contained a relational DBMS. System Relational, or System R, was a research prototype developed in the 1970s. DB2 has its roots back to the beginning of the seventies when Dr. E.F. Codd, working for IBM, described the theory of relational databases and in June of 1970 published the model for data manipulation. To apply the model Codd needed a relational database language which he named Alpha. At the time IBM didn't believe in the potential of Codd's ideas, leaving the implementation to a group of programmers not under Codd's supervision, who violated several fundamentals of Codd's relational model; the result was Structured English QUEry Language or SEQUEL. IBM soon changed the name to the current acronym, SQL, short for Structured Query Language, because SEQUEL had already been trademarked. A database management system (DBMS) is a computer program (or more typically, a suite of them) designed to manage a database, a large set of structured data, and run operations on the data requested by numerous users. ... SQL/DS (Structured Query Language/Data System) was IBMs first commercial implementation for its mainframe computers of a DBMS (Database Management System) built around the SQL language. ... System R is a database system built as a research project at IBM San Jose Research (now IBM Almaden Research Center) in the 1970s. ... System R is a database system built as a research project at IBM San Jose Research (now IBM Almaden Research Center) in the 1970s. ... Edgar Frank Ted Codd (August 23, 1923 â€“ April 18, 2003) was a British computer scientist who made seminal contributions to the theory of relational databases. ... SQL (IPA: or ) is a computer language designed for the retrieval and management of data in relational database management systems, database schema creation and modification, and database object access control management. ...

Historically, it is interesting to note that when Informix acquired Illustra and made their database engine an object-SQL DBMS by introducing their Universal Server, both Oracle and IBM followed suit by changing their database engines to be capable of object-relational extensions. Moreover, in 2001, IBM bought Informix and in the following years incorporated Informix technology into the DB2 product suite. Today, DB2 can technically be considered to be an object-SQL DBMS. Informix is a family of relational database management system products from IBM, acquired in 2001 from a company (also called Informix or Informix Software) which dates its origins back to 1980. ... An object-relational database (ORD) or object-relational database management system (ORDBMS) is a relational database management system that allows developers to integrate the database with their own custom data types and methods. ... Informix is a family of relational database management system products from IBM, acquired in 2001 from a company (also called Informix or Informix Software) which dates its origins back to 1980. ... An object-relational database (ORD) or object-relational database management system (ORDBMS) is a relational database management system that allows developers to integrate the database with their own custom data types and methods. ...

For many years DB2 was exclusively available on IBM mainframes. Later IBM brought DB2 to other platforms, including OS/2, UNIX and Windows servers, then Linux (including Linux on zSeries) and PDAs. This process was mainly undertaken through the 1990s. The inspiration for DB2's implementation details came in part from IBM DL/1 and IBM IMS, both initially hierarchical and then later network (or CODASYL) databases. DB2 is also embedded in the i5/OS operating system for IBM System i (iSeries, formerly the AS/400), and versions are available for z/VSE and z/VM. An earlier version was available for OS/2 and was called DB2/2. SAS 8 on an IBM mainframe, seen here via one of its user interfaces, classic 3270 emulation. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Filiation of Unix and Unix-like systems Unix (officially trademarked as UNIXÂ®, sometimes also written as or Â® with small caps) is a computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and Douglas McIlroy. ... Windows redirects here. ... This article is about operating systems that use the Linux kernel. ... Linux on zSeries (or Linux on System z9) is the preferred collective term for the Linux operating system and GNU/Linux software compiled to run on IBM mainframes, especially zSeries servers. ... User with Treo (PDA with smartphone functionality) Personal digital assistants (PDAs) are handheld computers, but have become much more versatile over the years. ... Data Language/1 (DL/1) is the language system used to access IBMâ€™s IMS databases, and its data communication system. ... Information Management System (IMS) is a joint hierarchical database and information management system. ... CODASYL (often spelt Codasyl) is an acronym for COnference on DAta SYstems Languages. This was a IT industry consortium formed in 1959 to guide the development of a standard programming language that could be used on many computers. ... OS/400 is an operating system used on IBMs line of AS/400 (now called iSeries) minicomputers. ... i5 Model 570 (2006) The Application System/400 (also known as AS/400), now System i (also known as iSeries), is a type of minicomputer produced by IBM. It was first produced in 1988. ... Enterprise class server and the successor to the AS/400. ... i5 Model 570 (2006) The Application System/400 (also known as AS/400, iSeries (since 2000) and System i5 (since 2006)) is a type of minicomputer produced by IBM. It was first produced in 1988 and, as of 2006, is still in production. ... VSE (Virtual Storage Extended) is an operating system on the IBM System/370 and System/390 mainframe computers. ... VM is an early and influential virtual machine operating system from IBM, apparently the first true virtual machine system. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

Over the years DB2 has driven numerous hardware enhancements, particularly on IBM System z with such features as Parallel Sysplex data sharing. In fact, DB2 UDB Version 8 for z/OS now requires a 64-bit system and cannot run on earlier processors, and DB2 for z/OS maintains certain unique software differences in order to serve its sophisticated customers. Although the ultimate expression of software-hardware co-evolution is the IBM mainframe, to some extent that phenomenon occurs on other platforms as well, as IBM's software engineers collaborate with their hardware counterparts. IBM System z9 Enterprise Class System z9 is the newest and most powerful line of IBM mainframes. ... In computing, a Parallel Sysplex is a cluster of IBM mainframes acting together in a single system image, usually with z/OS. A Parallel Sysplex combines data sharing (typically using Peer to Peer Remote Copy) and parallel computing to allow a cluster of up to 32 computers to share a... z/OS Welcome Screen seen through a terminal emulator The title of this article begins with a capital letter due to technical limitations. ... In computing, a 64-bit component is one in which data are processed or stored in 64-bit units (words). ...

In the mid-1990s, IBM released a clustered DB2 implementation called DB2 Parallel Edition, which initially ran on AIX. This edition allowed scalability by providing a shared nothing architecture, in which a single large database is partitioned across multiple DB2 servers that communicate over a high-speed interconnect. This DB2 edition was eventually ported to all Linux, UNIX, and Windows (LUW) platforms and was renamed to DB2 Extended Enterprise Edition (EEE). IBM now refers to this product as the Database Partitioning Feature (DPF) and sells it as an add-on to their flagship DB2 Enterprise product. A shared nothing architecture is a distributed database architecture without a single point of failure. ...

In mid 2006, IBM announced "Viper," the codename for DB2 9 on distributed platforms and for DB2 9 on z/OS. IBM claims that the new DB2 will be the first relational database to store XML "natively". Other enhancements include OLTP-related improvements for distributed platforms, business intelligence/data warehousing-related improvements for z/OS, more self-tuning and self-managing features, additional 64-bit exploitation (especially for z/OS), stored procedure performance enhancements for z/OS, and continued convergence of the SQL vocabularies between z/OS and distributed platforms. Distributed computing is a method of computer processing in which different parts of a program are run simultaneously on two or more computers that are communicating with each other over a network. ... The Extensible Markup Language (XML) is a general-purpose markup language. ... OLTP (Online Transaction Processing) is a form of transaction processing conducted via computer network. ... The term business intelligence (BI) dates to 1958. ... A data warehouse is a record of an enterprises past transactional and operational activities, stored in a database. ...

DB2 9 on distributed platforms began shipping worldwide on July 28, 2006, with pricing starting at $4,874 per processor or $165 per user (minimum of 5 users) for DB2 9 Express, including one year of support.^[1] DB2 for z/OS pricing starts at about $4,450 per month, including support. Distributed computing is a method of computer processing in which different parts of a program are run simultaneously on two or more computers that are communicating with each other over a network. ... is the 209th day of the year (210th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ...

Editions

DB2 is available in several "editions," or licensing arrangements. By opting for a reduced-feature "edition," IBM allows customers to avoid paying for database features which they do not need. Sample editions include the Express, Workgroup, and Enterprise Edition. The most sophisticated edition for Linux/UNIX/Windows is DB2 Data Warehouse Enterprise Edition, or DB2 DWE for short. This edition is intended for mixed workload (OLTP and data warehousing) or business intelligence (BI) implementations. DB2 DWE includes several "BI" features such as ETL, data mining, OLAP acceleration, and in-line analytics. The term business intelligence (BI) dates to 1958. ... ETL also means Express Toll Lanes, see Express Toll Lanes. ... Data mining is the principle of sorting through large amounts of data and picking out relevant information. ... Online Analytical Processing, or OLAP (IPA: ), is an approach to quickly provide answers to analytical queries that are multidimensional in nature. ...

DB2 for z/OS is available under its own licensing terms. Starting with Version 8, IBM brought DB2 for z/OS and for the other platforms into much closer alignment. (Previously there were significant differences in SQL vocabularies, for example.) DB2 for z/OS has some exclusives — notably Multi-Level Security (MLS), extremely large table sizes, and hardware-assisted compression — owing to its special environment and the demanding needs of its customers. DB2 for z/OS has always been known for its leading OLTP performance and capabilities, and for its reliability and availability to support mission-critical business operations, but the z/OS version is now starting to acquire BI features as well, such as materialized query tables (MQTs) and star schema. Oracle's CEO Larry Ellison commented that DB2 for z/OS is the one competitive database he respects and admires.^[2] z/OS Welcome Screen seen through a terminal emulator The title of this article begins with a capital letter due to technical limitations. ... Oracle Corporation (NASDAQ: ORCL) is one of the major companies developing database management systems (DBMS), tools for database development, middle-tier software, enterprise resource planning software (ERP), customer relationship management software (CRM) and supply chain management (SCM) software. ... Lawrence Joseph Ellison (born August 17, 1944) is the co-founder and CEO of Oracle Corporation, a major database software company. ...

On January 30th, 2006, IBM released a no-charge version of DB2 called DB2 Express-C. This was an expected response to the recently announced free versions of Oracle 10g and Microsoft SQL Server. Unlike Microsoft or Oracle's free editions, Express-C has no limit on number of users or on database size. While versions 8.2 and 9.1 of DB2 Express-C imposed hardware limits on the server on which it ran, DB2 Express-C 9.5 can run on Windows and Linux machines of any size, but the database engine will not utilize more than two CPU cores and 2GB RAM. In 2007, IBM introduced a yearly support subscription called the Fixed Term License (FTL), which offers a year of telephone support for Express-C for US$3000 per server. Purchasing the FTL also allows the DB2 Express-C engine to use up to four CPU cores and 4GB RAM. Users of DB2 Express-C who don't purchase an FTL subscription can receive support and assistance on a free, public web forum staffed by IBM technicians and other DB2 users. The term Oracle database may refer either to the database management system (DBMS) software released by Oracle Corporation as Oracle RDBMS, or to any of the individual databases managed by such software. ... Microsoft Corporation, (NASDAQ: MSFT, HKSE: 4338) is a multinational computer technology corporation with global annual revenue of US$44. ...

Competition

Historically, prime position in the database management software market has been held by Oracle. On May 3, 2004, IBM's head of database development and sales, Janet Perna, claimed their main competitors were Oracle in the context of advanced transaction handling and Teradata in the context of decision support systems (e.g. data warehousing). However, there are competitors in smaller markets, including Microsoft SQL Server (which is only available for Microsoft Windows), open source products such as FirebirdSQL, PostgreSQL and MySQL, and niche players such as Sybase and MaxDB. Teradata Teradata Corporation (NYSE: TDC) is the global leader in data warehousing and analytic technologies. ... Decision support systems are a class of computer-based information systems including knowledge based systems that support decision making activities. ... A data warehouse is the main repository of an organizations historical data, its corporate memory. ... Microsoft SQL Server is a relational database management system (RDBMS) produced by Microsoft. ... Open source refers to projects that are open to the public and which draw on other projects that are freely available to the general public. ... Firebird (sometimes called FirebirdSQL) is a relational database offering many ANSI SQL-92 and SQL-99 features that runs on Linux, Windows, and a variety of Unix platforms. ... PostgreSQL is a free software object-relational database management system (ORDBMS), released under a BSD-style license. ... MySQL (pronounced (IPA) , my S-Q-L[1]) is a multithreaded, multi-user SQL database management system (DBMS)[2] which has, according to MySQL AB, more than 10 million installations. ... Sybase Inc. ... MaxDB is an ANSI SQL-92 (entry level) compliant relational database management system (RDBMS) from SAP AG, which was delivered also by MySQL AB from 2003 to 2007. ...

In the clustered DBMS arena, where databases can grow to many terabytes, IBM's Database Partitioning Feature (DPF) is often pitted against Oracle Real Application Clusters (RAC), a shared-disk implementation formerly known as Oracle Parallel Server (OPS).

DB2 for z/OS arguably has fewer direct competitors, but Oracle is attracting customers to its Linux on zSeries products, although apparently not at the expense of DB2. CA-Datacom and Software AG's Adabas are competing relational databases for z/OS, and there are certain niche products as well (Model 204, SUPRA SQL^[3], NOMAD, etc.) Oracle has a 31-bit RDBMS available for z/OS. Non-relational databases that "compete" include IMS, and CA-IDMS, among others. Datacom refers to the following: * a large international support group for CA-Datacom (http://www. ... Adabas is Software AGâ€™s advanced database management system. ... Model 204 is a database system for IBM and compatible mainframes, running under OS/390. ... NOMAD was developed by National CSS, Inc, in Stamford (later Wilton), CT, starting in 1973. ... ESA/390 (Enterprise Systems Architecture/390) is IBMs 31-bit mainframe computing design, copied by Amdahl, Hitachi, and Fujitsu among other competitors. ... Information Management System (IMS) is a joint hierarchical database and information management system. ... IDMS (Integrated Database Management System) is a (network) CODASYL database management system first developed at B.F. Goodrich and later marketed by Cullinane Database Systems (renamed Cullinet in 1983). ...

IBM and DB2 are frequently at or near the top of the TPC-C and TPC-H industry benchmarks published on the Transaction Processing Performance Council's website. Transaction Processing Performance Council (TPC) is a non-profit organization founded in 1985 to define transaction processing and database benchmarks and to disseminate objective, verifiable TPC performance data to the industry. ... Transaction Processing Performance Council (TPC) is a non-profit organization founded in 1985 to define transaction processing and database benchmarks and to disseminate objective, verifiable TPC performance data to the industry. ... Transaction Processing Performance Council (TPC) is a not-for-profit organization which sets performance benchmarks for IT applications, such as databases. ...

In 2006 IBM stepped up its competition in the emerging data warehouse appliance market by releasing a product line of pre-configured hardware/software systems combining DB2 Data Warehouse Edition with either IBM system p (AIX) or IBM system x (Linux) servers. This family of "warehouse appliance-like" systems was given the name IBM Balanced Configuration Unit, or BCU, and is aimed at the warehouse appliance market typified by Netezza and DATAllegro, but it differentiates itself in that it uses the full-featured version of DB2 instead of a single-purpose warehouse-oriented RDBMS. // Netezza Corporation produces a data warehouse appliance, Netezza Performance Server (NPS). ...

Technical information

DB2 can be administered from either the command-line or a GUI. The command-line interface requires more knowledge of the product but can be more easily scripted and automated. The GUI is a multi-platform Java client that contains a variety of wizards suitable for novice users. DB2 supports both SQL and XQuery. DB2 has native implementation of XML data storage, where XML data is stored as XML(not as relational data or CLOB data) for faster access using XQuery.

DB2 has APIs for .NET CLI, Java, Python, Perl, PHP, Ruby, C++, C, REXX, PL/I, COBOL, RPG, FORTRAN, and many other programming languages. DB2 also supports integration into the Eclipse and Visual Studio .NET integrated development environments. The Microsoft . ... Visual overview of the Common Language Infrastructure (CLI) The Common Language Infrastructure (CLI) is an open specification developed by Microsoft that describes the executable code and runtime environment that form the core of the Microsoft . ... Java language redirects here. ... Python is a high-level programming language first released by Guido van Rossum in 1991. ... Wikibooks has a book on the topic of Perl Programming Perl is a dynamic programming language created by Larry Wall and first released in 1987. ... For other uses, see PHP (disambiguation). ... Ruby is a reflective, dynamic, object-oriented programming language. ... C++ (pronounced see plus plus, IPA: ) is a general-purpose programming language with high-level and low-level capabilities. ... C is a general-purpose, block structured, procedural, imperative computer programming language developed in 1972 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system. ... REXX (REstructured eXtended eXecutor) is an interpreted programming language which was developed at IBM. It is a structured high-level programming language which was designed to be both easy to learn and easy to read. ... PL/I (Programming Language One, pronounced pee el one) is an imperative computer programming language designed for scientific, engineering, and business applications. ... COBOL (pronounced //) is a Third-generation programming language, and one of the oldest programming languages still in active use. ... RPG is a native programming language for IBMs iSeries servers - the latest generation of midrange servers which included System/38, System/36, AS/400, iSeries and System i5 systems. ... Fortran (previously FORTRAN[1]) is a general-purpose[2], procedural,[3] imperative programming language that is especially suited to numeric computation and scientific computing. ... Eclipse is an open source platform-independent software framework for delivering what the project calls rich-client applications, as opposed to thin client browser-based applications. ... The Visual Studio . ... An integrated development environment (IDE), also known as integrated design environment and integrated debugging environment, is a programming environment that has been packaged as an application program,that assists computer programmers in developing software. ...

Error processing

An important feature of DB2 computer programs is the error processing. The SQL communications area (SQLCA) structure is used within the DB2 program to return error information to the application program after every API call for an SQL statement. The error diagnostic is held in the field SQLCODE within the SQLCA block. Image File history File links Wikibooks-logo-en. ... Wikibooks logo Wikibooks, previously called Wikimedia Free Textbook Project and Wikimedia-Textbooks, is a wiki for the creation of books. ... A computer program (often simply called a program) is an example of computer software that prescribes the actions (computations) that are to be carried out by a computer. ... Computer software (or simply software) refers to one or more computer programs and data held in the storage of a computer for some purpose. ... API and Api redirect here. ... SQL (IPA: or ) is a computer language designed for the retrieval and management of data in relational database management systems, database schema creation and modification, and database object access control management. ... SQL Return Codes are used on a day to day basis for the diagnosis of programming failures as a result of SQL calls by DB2 computer programs. ...

The SQL return code values are: SQL Return Codes are used on a day to day basis for the diagnosis of programming failures as a result of SQL calls by DB2 computer programs. ...

See SQL return codes for a more comprehensive list of the SQLCODEs. SQL Return Codes are used on a day to day basis for the diagnosis of programming failures as a result of SQL calls by DB2 computer programs. ...

Leadership

Janet Perna was General Manager of IBM Software Group's Information Management division until her retirement from IBM in July, 2005. She was replaced by Ambuj Goyal.^[4]

See also

Geneva ERS is an enterprise reporting system for IBM mainframes. ... DB2 Magazine is a U.S.-based magazine published by CMP Technology and sponsored by IBM Corp. ... SQL/DS (Structured Query Language/Data System) was IBMs first commercial implementation for its mainframe computers of a DBMS (Database Management System) built around the SQL language. ... Datalog is a query and rule language for deductive databases that syntactically is a subset of Prolog. ...

References

External links

Categories: Proprietary database management systems | IBM software | 1982 introductions The OSGi Alliance (formerly known as the Open Services Gateway initiative - now an obsolete name) is an open standards organization founded in March 1999. ... For other uses, see IBM (disambiguation) and Big Blue. ... For other uses, see Corporation (disambiguation). ... Chairman of the Board redirects here. ... Kenneth Irvine Chenault (born 2 June 1951) is a former president (1997-2001) and current Chief Executive Officer (2001-present) of American Express. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Dr. Shirley Ann Jackson (born August 5, 1946) is the 18th President of Rensselaer Polytechnic Institute. ... Principal occupation: Chairman and Chief Executive Officer, Caterpillar Inc. ... Samuel J. Palmisano Samuel J. Palmisano (born July 29, 1951) is chairman of the board and chief executive officer of the IBM Corporation. ... Sidney Taurel was born February 9, 1949 in Casablanca, Morocco. ... Lorenzo H. Zambrano TreviÃ±o (b. ... Layout of the IBM Cell die Cell is a microprocessor architecture jointly developed by a Sony, Toshiba, and IBM, an alliance known as STI. The architectural design and first implementation were carried out at the STI Design Center over a four-year period beginning March 2001 on a budget reported... SAS 8 on an IBM mainframe, seen here via one of its user interfaces, classic 3270 emulation. ... IBM PC (IBM 5150) with keyboard and green screen monochrome monitor (IBM 5151), running MS-DOS 5. ... POWER is a RISC instruction set architecture designed by IBM. The name is a acronym for Performance Optimization With Enhanced RISC. POWER is also the name of a series of microprocessors that implements the instruction set architecture. ... This article does not cite any references or sources. ... Lotus Software (called Lotus Development Corporation before its acquisition by IBM) is an American software company with its headquarters in Cambridge, Massachusetts. ... Rational Software was an independent software development company until 2003, when it was bought by IBM. It sought to advance its customers practice of Modern Software Engineering through process, tools, and services. ... Tivoli Software is the systems management brand of the IBM Software Group. ... WebSphere refers to a brand of IBM software products that are mostly proprietary[1], although the term also popularly refers to one specific product: WebSphere Application Server (WAS). ... IBM Global Services is the worlds largest business and technology services provider. ... IBM India, significantly, is now the fourth largest employer in the Indian IT industry - only behind TCS, Infosys and Wipro. ... IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones since they almost exactly duplicated all the significant features of the PC, XT, or AT internal design, facilitated by various manufacturers... The IBM Public License is a free software / open-source software license used by IBM. It is ratified by the Open Source Initiative and Free Software Foundation (FSF). ... // For issues and trends that span particular time periods, see major events, trends, and technologies, below. ... The following is a partial list of IBM acquisitions and spinoffs. ... The following is a list of products from the International Business Machines (IBM) Corporation and its predecessor corporations, beginning in the 1890s, and spanning punched card machinery, time clocks, and typewriters, via mainframe computers and minicomputers, to microprocessors, PCs, laptop PCs, and more. ... Image File history File links No higher resolution available. ... The United States dollar is the official currency of the United States. ... A fiscal year (or financial year or accounting reference date) is a 12-month period used for calculating annual (yearly) financial statements in businesses and other organizations. ... The New York Stock Exchange (NYSE), nicknamed the Big Board, is a New York City-based stock exchange. ... A database management system (DBMS) is computer software designed for the purpose of managing databases. ... A data model is not just a way of structuring data: it also defines a set of operations that can be performed on the data. ... Database normalization is a design technique for structuring relational database tables. ... Database tables/indexes are typically stored in memory or on hard disk in one of many forms, ordered/unordered Flat files, ISAM, Heaps, Hash buckets or B+ Trees. ... According to Elmasri and Navathe (2004, p. ... An example of a database that has not enforced referential integrity. ... Relational algebra, an offshoot of first-order logic, is a set of relations closed under operators. ... The relational calculus refers to the two calculi, the tuple calculus and the domain calculus, that are part of the relational model for databases and that provide a declarative way to specify database queries. ... A relational database is a database that conforms to the relational model, and refers to a databases data and schema (the databases structure of how that data is arranged). ... A relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd. ... The relational model for database management is a database model based on predicate logic and set theory. ... In computer science, transaction processing is information processing that is divided into individual, indivisible operations, called Each transaction must succeed or fail as a complete unit; it cannot remain in an intermediate state. ... This article is about computing. ... For other uses, see Acid (disambiguation). ... The Greek lowercase omega (Ï‰) character is historically used by academics to represent Null in relational databases. ... In the relational model a candidate key of a relation variable (relvar) is a set of attributes of that relvar such that (1) at all times it holds in the relation assigned to that variable that there are no two distinct tuples with the same values for these attributes and... In the context of relational databases, a foreign key is a referential constraint between two tables[1]. The foreign key identifies a column or a set of columns in one (referencing) table that refers to a column or set of columns in another (referenced) table. ... In database design, a primary key is a value that can be used to identify a unique row in a table. ... A superkey is defined in the relational model as a set of attributes of a relation variable (relvar) for which it holds that in all relations assigned to that variable there are no two distinct tuples (rows) that have the same values for the attributes in this set. ... A surrogate key is a unique primary key generated by the relational database management system that is not derived from any data in the database and whose only significance is to act as the primary key. ... A database trigger is procedural code that is automatically executed in response to certain events on a particular table in a database. ... In database theory, a view is a virtual or logical table composed of the result set of a query. ... In relational databases, SQL databases, and flat file databases, a table is a set of data elements (values) that is organized using a model of horizontal rows and vertical columns. ... In database packages, the term cursor refers to a control structure for the successive traversal (and potential processing) of records in a result set as returned by a query. ... In in the field of databases in computer science, a transaction log (also database log or binary log) is a history of actions executed by a database management system to guarantee ACID properties over crashes or hardware failures. ... A database transaction is a unit of interaction with a database management system or similar system that is treated in a coherent and reliable way independent of other transactions. ... A database index is a data structure that improves the speed of operations in a table. ... A stored procedure is a subroutine available to applications accessing a relational database system. ... A partition is a division of a logical database or its constituting elements into distinct independent parts. ... SQL (IPA: or ) is a computer language designed for the retrieval and management of data in relational database management systems, database schema creation and modification, and database object access control management. ... An SQL SELECT statement returns a result set of records from one or more tables. ... A SQL INSERT statement adds one or more records to a table in a relational database. ... An UPDATE statement in SQL changes data in one or more records in a relational database management system. ... Wikipedia does not have an article with this exact name. ... An SQL DELETE statement removes one or more records from a table. ... A JOIN clause in SQL combines records from two tables in a relational database and results in a new (temporary) table, also called a joined table. Structured Query Language (SQL:2003) specifies two types of joins: inner and outer. ... In SQL the UNION operator combines the results of two SQL queries into a single table of all matching rows. ... A CREATE statement in SQL creates an object inside of a relational database management system (RDBMS). ... A DROP statement in SQL removes an object from a relational database management system (RDBMS). ... It has been suggested that this article or section be merged into Database transaction. ... A COMMIT statement in SQL ends a transaction within a relational database management system (RDBMS) and makes all changes visible to other users. ... In database technologies, a rollback is an operation which returns the database to some previous state. ... The Truncate statement removes all the data from a table. ... An ALTER statement in SQL changes the properties of an object inside of a relational database management system (RDBMS). ... A relational database is a database that conforms to the relational model, and refers to a databases data and schema (the databases structure of how that data is arranged). ... A simple diagram depicting conversion of a CSV-format flat file database table into a relational database table. ... A deductive database system is a database system which can make deductions (ie: infer additional rules or facts) based on rules and facts stored in the (deductive) database. ... A dimensional database is one which, rather than representing data in multiple relations (as a relational database does), represents key data entities as different dimensions. ... In a hierarchical data model, data are organized into a tree-like structure. ... The network model is a database model conceived as a flexible way of representing objects and their relationships. ... In an object oriented database, information is represented in the form of objects as used in Object-Oriented Programming. ... An object-relational database (ORD) or object-relational database management system (ORDBMS) is a relational database management system that allows developers to integrate the database with their own custom data types and methods. ... A temporal database is a database management system with built-in time aspects, e. ... An XML database is a data persistence software system that allows data to be imported, accessed and exported in the XML format. ... In computer science -- more specifically, in the field of databases -- concurrency control is a method used to ensure that database transactions are executed in a safe manner (i. ... Query languages are computer languages used to make queries into databases and information systems. ... The query optimizer is a component of database management system that is used to analyzes queries submitted to database server for execution, and then determines the optimal way to execute the query. ... A query plan (or query execution plan) is an set of steps used to access information in a SQL relational database management system. ... In computing, Open Database Connectivity (ODBC) provides a standard software API method for using database management systems (DBMS). ... JDBC is an API for the Java programming language that defines how a client may access a database. ... The following is a list of object-oriented database management systems. ... This article or section is not written in the formal tone expected of an encyclopedia article. ... See DBMS for a shorter list of â€œtypicalâ€, representative database management systems. ... The following tables compare general and technical information for a number of relational database management systems. ...

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