From a technical standpoint, DBMSs can differ widely. The terms relational, network, flat, and hierarchical all refer to the way a DBMS organizes information internally. The internal organization can affect how quickly and flexibly you can extract information.
Requests for information from a database are made in the form of a query, which is a stylized question. For example, the query
SELECT ALL WHERE NAME = "SMITH" AND AGE > 35
requests all records in which the NAME field is SMITH and the AGE field is greater than 35. The set of rules for constructing queries is known as a query language. Different DBMSs support different query languages, although there is a semi-standardized query language called SQL (structured query language). Sophisticated languages for managing database systems are called fourth-generation languages, or 4GLs for short.
The information from a database can be presented in a variety of formats. Most DBMSs include a report writer program that enables you to outputdata in the form of a report. Many DBMSs also include a graphics component that enables you to output information in the form of graphs and charts.
Oracle Corporation home page The Oracle home page provides links to their line of products and solutions, corporate information and news, support, education, events, and partner information.
KB Systems home page KB (Knowledge Based) Systems is a provider of relational database management tools for the M application development and user community. This home page offers links to their products and services, company information, and related Web links.
Object Database Management Group Offers information about ODMG, a consortium of database management system vendors who are working on progressing specific standards of customer software across DBMS products. There are also direct links to more detailed information about ODMG.
Database Journal An excellent resource for database professionals.
