翻訳と辞書 Words near each other ・ supervisory control and data acquisition ・ superzap ・ supplementary ideographic plane ・ support ・ supremum ・ sure ・ surfing ・ surge ・ surjection ・ surjective ・ surrogate key ・ suspension ・ suzie cobol ・ sv ・ svc ・ svg ・ svga ・ svga monitor ・ svid ・ svr4 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 surrogate key ： FOLDOC surrogate key A unique primary key generated by the RDBMS that is not derived from any data in the database and whose only significance is to act as the primary key. A surrogate key is frequently a sequential number (e.g. a Sybase "{identity column}") but doesn't have to be. Having the key independent of all other columns insulates the database relationships from changes in data values or database design and guarantees uniqueness. Some database designers use surrogate keys religiously regardless of the suitability of other {candidate keys}. However, if a good key already exists, the addition of a surrogate key will merely slow down access, particularly if it is indexed. Compare: intelligent key. (1999-12-07) 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.