On 'Update Semantics and Relational Views'.
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Abstract : A shared database encompasses data of interest to a variety of users. A database view provides a class of users with an image of a portion of the data presented according to the needs of these users. The ability to translate updates specified against the view into updates specified against the database is necessary to allow more effective use of views. Since a user accessing the database through a view has limited knowledge of the entire domain of the database, it is necessary to limit the effect on others of a particular user's view update. Furthermore, there may be many ways to translate a particular view update into database updates. Bancilhon and Spyratos propose the notion of a constant complementary view, which partially solves the problem of view updates by addressing these two issues. The authors present a reasonable view update translator that does not preserve any complement. This illustrates the restrictive consequences of the requirement that a complement remain constant. (Author)