Algebraic Properties of Bag Data Types
نویسنده
چکیده
We explore the implications of supporting bags (i.e. multisets) in a data model and associated query language, and present some formal results concerned with the algebraic properties of bags. We extend previous work to provide a formal basis for query optimization and for defining the appropriate semantics for bag operations in data models supporting ba.gs.
منابع مشابه
Algebraic Data Types and Induction in CRL
In this paper a thorough treatment of elementary data types is given in the speciication language CRL, which integrates data speciication with process speciication. Data speciication in CRL is directly based on the theory of algebraic data types, which is an equational theory, extended with a rule for constructor induction. Speciications of the following data types and structures are given: boo...
متن کاملSome Algebraic and Combinatorial Properties of the Complete $T$-Partite Graphs
In this paper, we characterize the shellable complete $t$-partite graphs. We also show for these types of graphs the concepts vertex decomposable, shellable and sequentially Cohen-Macaulay are equivalent. Furthermore, we give a combinatorial condition for the Cohen-Macaulay complete $t$-partite graphs.
متن کاملUniformities and covering properties for partial frames (II)
This paper is a continuation of [Uniformities and covering properties for partial frames (I)], in which we make use of the notion of a partial frame, which is a meet-semilattice in which certain designated subsets are required to have joins, and finite meets distribute over these. After presenting there our axiomatization of partial frames, which we call $sels$-frames, we added structure, in th...
متن کاملAlgebraic distance in algebraic cone metric spaces and its properties
In this paper, we prove some properties of algebraic cone metric spaces and introduce the notion of algebraic distance in an algebraic cone metric space. As an application, we obtain some famous fixed point results in the framework of this algebraic distance.
متن کاملUniformities and covering properties for partial frames (I)
Partial frames provide a rich context in which to do pointfree structured and unstructured topology. A small collection of axioms of an elementary nature allows one to do much traditional pointfree topology, both on the level of frames or locales, and that of uniform or metric frames. These axioms are sufficiently general to include as examples bounded distributive...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1991