Titlebook: Answering Queries Using Views, Second Edition; Foto Afrati,Rada Chirkova Book 2019Latest edition Springer Nature Switzerland AG 2019

失敗主義者

Finding Equivalent Rewritings,eration to the fragment of the language of conjunctive queries with aggregation that is called “central rewritings.” Our focus will be on finding (minimal) equivalent rewritings in an efficient way. Other languages for rewritings will be discussed in other parts of the book.

折磨

Book 2019Latest editionintegration, data warehousing, website design and, recently, database-as-a-service and data placement in cloud systems...This book assembles foundational work on answering queries using views in a self-contained manner, with an effort to choose material that constitutes the backbone of the research.

Handedness

https://doi.org/10.1007/978-3-322-94951-6eration to the fragment of the language of conjunctive queries with aggregation that is called “central rewritings.” Our focus will be on finding (minimal) equivalent rewritings in an efficient way. Other languages for rewritings will be discussed in other parts of the book.

不滿分子

Queries and Views,to which they give rise (Section 1.2). An informal discussion follows about specific technical problems in answering queries using views with concrete examples (Section 1.3). Then, for completeness and consistency of notation, we give formal definitions for the relational data model and query langua

整頓

有幫助

Answering Queries in Data Exchange,, for a set of views . defined on the schema of ., we are given an instance ., which is either the set of all tuples in .(.) or its subset. So, being unable to compute . directly on ., we have to find techniques for answering . on the instance . whose schema is that of the view relations. The approa

overreach

CLASP

Tree-Structured Records Queried with SQL Dialect,d to think of the instances of a tree data type as if they were tuples of a relation. We present in this chapter a data model which is defined by neither a standard relation (like the relational model) nor by a tree (like an XML document), but it is a “combination” of both. Thus, it enables the use

粗糙

事先無準(zhǔn)備

2153-5418 ve query languages. Chapter 8 presents the data model for XML documents and the XPath query language, and Chapter 9 provides a theoretical presentation of tree-978-3-031-00743-9978-3-031-01871-8Series ISSN 2153-5418 Series E-ISSN 2153-5426