DB2 Middleware and Connectivity

DB2 is a very open database and provides a variety of options for connecting to DB2 and non-DB2 databases.

  • DB2 client code is required on workstations for remote users to access a DB2 database or on servers for remote programs or applications to access a DB2 database.

  • DB2 Connect provides support for applications executing on UNIX and Intel platforms to transparently access DB2 databases on the OS/400, VSE/VM, z/OS, and Linux on zSeries environments. Note that DB2 Connect is not required to access DB2 databases on UNIX or Intel platforms.

  • DB2 Information Integrator integrates data and content sources across the enterprise, based on the SQL programming model product, which allows DB2 clients to access, join, and update tables from heterogeneous databases, such as Sybase, Informix, and Microsoft SQL Server.

  • DB2 Information Integrator for Content (EIP) integrates data and content sources across and beyond the enterprise, based on the content programming model.

DB2 Universal Database Clients

The DB2 product enables clients that are used by applications or workstations to communicate with DB2 servers. There are three types of DB2 clients.

  1. DB2 runtime client enables workstations running a variety of platforms to access DB2 databases. It includes basic connectivity onlynothing more and nothing less. If you need to establish connectivity to a remote DB2 server or DB2 Connect Gateway, which helps you access DB2 on a mainframe or host system, such as DB2 UDB for z/OS, the runtime client provides this.

  2. DB2 administration client provides the ability for workstations from a variety of platforms to access and administer DB2 databases through the Command Center, Control Center, or Configuration Assistant. Additional tools are included for monitoring and general administration: the Replication Center. A DB2 administration client has all the features of the DB2 runtime client and also includes all the DB2 administration tools, documentation, and support for thin clients.

  3. DB2 application development client provides the tools and environment you need to develop applications that access DB2 servers. You can build and run DB2 applications with a DB2 application development client. Of course, because this is a DB2 client, it also gives users the power of connectivity and includes the functions of the preceding two clients.

The DB2 clients are supported on a variety of platforms, including Windows, AIX, HP-UX, Linux, and Solaris.

DB2 Connect

DB2 Connect provides connectivity to IBM mainframe databases for e-business and other applications running under various UNIX and non-UNIX operating systems. DB2 Connect has several connection solutions. DB2 Connect Personal Edition provides direct connectivity to zSeries or iSeries databases; DB2 Connect Enterprise Edition provides indirect connectivity that allows clients to access host databases through the DB2 Connect server. DB2 Connect Unlimited Edition is an additional solution that makes product selection and licensing easier.

DB2 Connect forwards SQL statements submitted by application programs to DB2 for z/OS, DB2 for VSE and VM, or DB2 for iSeries database servers. DB2 Connect can forward almost any valid SQL statement. DB2 Connect fully supports the common IBM SQL, as well as the DB2 Universal Database for z/OS, DB2 for VSE and VM, and DB2 for iSeries implementations of SQL.

DB2 Connect implements the Distributed Relational Database Architecture (DRDA) to reduce the cost and complexity of accessing data stored in DB2 for iSeries, DB2 UDB for z/OS, DB2 for VSE and VM, and other DRDA-compliant database servers. By fully exploiting DRDA, DB2 Connect offers a well-performing, low-cost solution with the system-management characteristics that customers require. In the DB2 Connect environment, the DB2 Connect workstation can function only as an application requester on behalf of application programs.

DB2 Connect allows clients to access data stored on data servers that implement the DRDA. The target database server for a DB2 Connect installation is known as a DRDA application server. The most commonly accessed DRDA application server is DB2 for z/OS. The database application must request the data from a DRDA application server through a DRDA application requester. DB2 Connect provides the DRDA application requestor functionality. The DRDA application server accessed using DB2 Connect could be any DB2 server on z/OS, VM and VSE, or iSeries.

A distributed request is a distributed database function that allows applications and users to submit SQL statements that reference two or more DBMSs or databases in a single statement, such as a join between tables in two DB2 for z/OS subsystems. DB2 Connect provides support for distributed requests across databases and DBMSs. You can, for example, perform a UNION operation between a DB2 table and an Oracle view. Supported DBMSs include DB2 UDB for Linux, UNIX, and Windows; DB2 for z/OS and DB2 for iSeries; and Oracle. Distributed request provides location transparency for database objects. Distributed request also provides compensation for DBMSs that do not support all the DB2 SQL dialect or certain optimization capabilities. Operations that cannot be performed under such a DBMS such as recursive SQL are run under DB2 Connect.

Multisite update, also known as distributed unit of work (DUOW) and two-phase commit, is a function that enables your applications to update data in multiple remote database servers and with guaranteed integrity. A distributed transaction can update any mix of supported database servers. For example, your application can update several tables in DB2 Universal Database on Windows, a DB2 for z/OS database, and a DB2 for iSeries database, all within a single transaction. DB2 products, including DB2 Connect, provide comprehensive support for multisite updates. This support is available for applications developed using regular SQL, as well as applications that use transaction monitor (TP monitor) products that implement the X/Open XA interface specification.

DB2 Information Integrator

DB2 Information Integrator provides integrated, real-time access to structured and unstructured information as if it were a single database, regardless of where it resides. The federated server lets users create an abstract relational view across diverse data, use existing reporting and development tools, and use cost optimizations for SQL. The replication server lets users manage data movement strategies, including distribution and consolidation models, and monitor synchronization processes.

Supported data sources include DB2 UDB, Informix, MS SQL Server, Oracle, Sybase, Teradata, ODBC, and others. Supported content sources include WebSphere MQ Message Queues, Lotus Notes, XML, Web Services, MS Excel Spreadsheets, and others. DB2 Information Integrator acts as middleware for access to heterogeneous data sources. With a single SQL statement, an application can transparently access, join, and update data located across multiple data sources. The access can be done without needing to know the location of the data or the specifics of the SQL dialects for the data source.

DB2 Information Integrator for Content (EIP)

DB2 Information Integrator for Content, formerly named Enterprise Information Portal, is an information-integration infrastructure that gives applications access to information sources from inside and outside the enterprise. From a Web browser or a portal, knowledge workers can concurrently access data and content from multiple sources, expanding the reach of their analysis and improving their productivity. DB2 Information Integrator for Content provides a federated search, direct connectors, and simultaneous access across the multiple repositories, workflow integration and Web crawling, and information mining.

Users can personalize data queries and search extensively for very specific needs across traditional and multimedia data sources. Developers can more rapidly develop and deploy portal applications with the information-integration application development toolkit.

DB2 for z. OS Version 8 DBA Certification Guide
DB2 for z/OS Version 8 DBA Certification Guide
ISBN: 0131491202
EAN: 2147483647
Year: 2003
Pages: 175
Authors: Susan Lawson

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