文档介绍：外文原文
Management Center of MySQL
Authors: Lauderdale, John
Tsang, Danny H. K.
Baciu, e
Issue Date: 2006
Citation: Proceedings of IEEE Visual '96, Melbourne, Australia, February 2006, p. 447-458
Database (sometimes spelled database) is also called an electronic database, referring to any collections of data, or information, that is anized for rapid search and retrieval by puter. Databases are structured to facilitate the storage, retrieval, modification and deletion of data in conjunction with various data-processing operations. Database can be stored on ic disk or tape, optical disk, or some other secondary storage device.
A database consists of a file or a set of files. The information in the these files may be broken down into records, each of which consists of one or more fields are the basic units of data storage, and each field typically contains information pertaining to one aspect or attribute of the entity described by the database. Using keywords and various mands, users can rapidly search, rearrange, group, and select the fields in many records to retrieve or create reports on particular aggregates of data.
Database records and files must anized to allow retrieval of the information. Early system were arranged sequentially (., alphabetically, numerically, or chronologically); the development of direct-access storage devices made possible random access to data via indexes. Queries are the main way users retrieve database information. Typically the user provides a string of characters, and puter searches the database for a corresponding sequence and provides the source materials in which those characters appear. A user can request, for example, all records in which the content of the field for a person’s last name is the word Smith.
In flat databases, records anized according to a simple list of entities; many simple databases for puters are flat in structure. The records in hierarchical databases anized in a treelike structure, with each level