Information about 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.

History

DB2 has a long history and was what some consider to be the first database product to use SQL.

The name DB2 was first given to the Database Management System or DBMS in 1982 when IBM released SQL/DS and DB2 on its mainframe platform. Prior to this, the product was named System Relational, or System R, which launched in 1978. 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.

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.

For many years DB2 was exclusively available on IBM mainframes. Later IBM brought DB2 to other platforms, including 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 is available for OS/2 and is called DB2/2.

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.

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.

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.

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.

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]

On January 30th, 2006, IBM released a no-charge edition of DB2 called . This was an expected response to the recently announced free versions of Oracle 10g and Microsoft SQL Server. Express-C will have no limit on number of users or database size. It is deployable on Windows and Linux machines with up to two processors (4 cores in total) and up to 4GB of memory.

Competition

Historically, prime position in the database management software market has tightly alternated between DB2 and 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.

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.

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.

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.

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.

Error Processing

An important feature of DB2 computer programs is the error processing. The error diagnostic is held in the field within the DB2 SQLCA block.

The SQL communications area (SQLCA) structure is used within the DB2 program to return error information to the application program. This information in the SQLCA and the SQLCODE field is updated after every API call for the SQL statement.

The SQLCODE field contains the . The code can be zero (0), negative or positive.

0 means successful execution.

Positive means successful execution with warnings. An example is +100 which means no rows found.

Negative means unsuccessful with an error. An example is -911 which means a timeout has occured with a rollback.

See for a more comprehensive list of the SQLCODEs.

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
• DB2 Magazine
• SQL/DS
• Datalog

References

• http://www.ibm.com/developerworks/db2

External links

• [https://www14.software.ibm.com/webapp/iwm/web/preLogin.do?lang=en_US&S_PKG=db2v9demo&source=sw-infomgt&S_TACT=105AGY59&S_CMP=WIKEDemo&ca=dtl-wikidb2demo IBM DB2 9 Demo]
• DB2 Tutorial
• IBM DB2 Support Forums
• DB2 Magazine
• DB2 Information Center
• International DB2 Users Group
• Implement OSGi components using DB2 Everyplace, WebSphere MQ Everyplace and WebSphere Everyplace Device Manager -- See also OSGi Alliance
• Blog about DB2 for z/OS
• DB2usa - Links to DB2 for z/OS documents available on the web
• IBM Webcast:[https://www14.software.ibm.com/webapp/iwm/web/preLogin.do?lang=en_US&source=dw-c-wcsdp&S_PKG=060607&S_TACT=105AGY59&S_CMP=WIKIWC&ca=dtl-wiki05wc2 Integrating Open Source into your Business]
• DB2 Content Manager OnDemand
• DB2 Enterprise Content Management
• DB2 Enterprise Content Management

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Topics in database management systems (DBMS)  •  • [ edit]
Concepts Database  Database models  Database storage  Relational model  Distributed DBMS  ACID  Null Relational database  Relational algebra  Relational calculus  Database normalization  Referential integrity  Relational DBMS  Primary key, Foreign key, Surrogate key, Superkey, Candidate key
Objects Trigger  View  Table  Cursor  Log  Transaction  Index  Stored procedure  Partition	Topics in SQL Select  Insert  Update  Merge  Delete  Join  Union  Create  Drop Begin work  Commit  Rollback  Truncate  Alter
Implementations of database management systems
Types of implementations Relational  Flat file  Deductive  Dimensional  Hierarchical  Object oriented  Object relational  Temporal  XML data stores
Database products Object-oriented (comparison)  Relational (comparison)	Components Query language  Query optimizer  Query plan  ODBC  JDBC