In the past decade, many parallel database systems have been developed, together with many languages and approaches to specify operations in these systems. A common background is still missing, however. This paper proposes an extended relational algebra for this purpose, based on the well-known ...
Nested tables in Oracle allow sets over multiple attributes, but do not easily support set-level comparisons on such attributes. As can be seen there is a need for an improved system and method of performing set-level comparison operations. BRIEF SUMMARY In one aspect of the present invention,...
The fundamental collection in the library is a 'table' which represents a loose covering over an existing collection: > (use'lazy-tables.core);; basic operations on tables. We can dereference to force evaluation of the table:> @(table) [] > @(table(repeat2{:a1})) [{:a1} {:a1}] ...
Division is an additional operation in relational algebra, it can be replaced by which set of the following operations equivalently :的答案是什么.用刷刷题APP,拍照搜索答疑.刷刷题(shuashuati.com)是专业的大学职业搜题找答案,刷题练习的工具.一键将文档转化为在
Relational algebra consists of six basic operations: select, ___, union, set difference, cartesian product, and rename.的答案是什么.用刷刷题APP,拍照搜索答疑.刷刷题(shuashuati.com)是专业的大学职业搜题找答案,刷题练习的工具.一键将文档转化为在线题库手
This paper presents DNA algorithms for five relational algebra database operations, selection, projection, union, set difference, and Cartesian product on so-called DNA databases. A DNA database is a database where data records are encoded as DNA strands. The five operations mentioned before are ...
Beaubouef, T., Petry, F., Buckles, B.: Extension of the relational database and its algebra with rough set techniques. Computational Intelligence 11, 233–245 (1995)Beaubouef, T., Petry, F., and Buckles, B., “Extension of the Relational Database and its Algebra with Rough Set ...
Section 2 describes the extended relational algebra in a sequential (centralized) database environment. Section 3 extends the sequential language to a parallel language by adding concepts for data distribution and process allocation. It is shown that these concepts nicely fit into the formal character...
Examples of simple SQL queries expressed via UQL has been already demonstrated. In this paper we present how operators of a multi-set extended relational algebra can be expressed by UQL operators.Piotr WisniewskiTrusted systems: 5th International Conference, INTRUST 2013, Graz, Austria, December 4-...
(3) The simple data format, bitmap operations, and bitwise arithmetic may make it convenient to integrate the various operations in a query, including the dynamic grouping of tuples and the set-level comparisons of values. Efficient and seamless integration with conventional operations such as ...