翻訳と辞書 Words near each other ・ Database audit ・ Database caching ・ Database catalog ・ Database cinema ・ Database connection ・ Database Console Commands (Transact-SQL) ・ Database Deployment Manager ・ Database design ・ Database Directive ・ Database dump ・ Database encryption ・ Database engine ・ Database engine tuning advisor ・ Database for bacterial group II introns ・ Database forensics ・ Database index ・ Database journalism ・ Database machine ・ Database Management Library ・ Database marketing ・ Database Marketing Agency ・ Database model ・ Database Nation ・ Database normalization ・ Database of Interacting Proteins ・ Database of Molecular Motions ・ Database of protein conformational diversity ・ Database of Recorded American Music ・ Database of Salon Artists ・ Database preservation Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Database index ： ウィキペディア英語版 Database index A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index data structure. Indexes are used to quickly locate data without having to search every row in a database table every time a database table is accessed. Indexes can be created using one or more columns of a database table, providing the basis for both rapid random lookups and efficient access of ordered records. An index is a copy of select columns of data from a table that can be searched very efficiently that also includes a low-level disk block address or direct link to the complete row of data it was copied from. Some databases extend the power of indexing by letting developers create indices on functions or expressions. For example, an index could be created on upper(last_name), which would only store the upper case versions of the last_name field in the index. Another option sometimes supported is the use of partial indices, where index entries are created only for those records that satisfy some conditional expression. A further aspect of flexibility is to permit indexing on user-defined functions, as well as expressions formed from an assortment of built-in functions. == Usage == 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Database index」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.