منابع مشابه
XPath Query Evaluation: Improving Time and Space Efficiency
Contemporary XPath query engines evaluate queries in time exponential in the sizes of input queries, a fact that has gone unnoticed for a long time. Recently, the first mainmemory evaluation algorithm for XPath 1.0 with polynomial time combined complexity, i.e., which runs in polynomial time both with respect to the size of the data and the queries, has been published (cf. [11]). In this paper,...
متن کاملStreaming XPath Subquery Evaluation
We describe a method for the streaming evaluation of XPath queries that have subqueries in predicates. Our method rewrites XPath queries into a set of predicate-free labeled linear-form expressions (LFEs). These LFEs are used to generate a pushdown transducer that enables efficient management of a buffer and hierarchical index at runtime. To the best of our knowledge, our method is the first to...
متن کاملTowards a Streamed XPath Evaluation
XPath is a language for addressing fragments of XML documents, used in query and transformation languages such as XQuery and XSLT. For many applications it is desirable to process XPath on the fly and progressively against data streams. This diploma thesis is devoted to streamed and progressive evaluation of XPath. A streamed and progressive XPath evaluation considerably reduces the needed memo...
متن کاملAdding Valid Time to XPath
In this paper we extend the XPath data model and query language to include valid time. XPath is a language for specifying locations within an XML document. We extend XPath’s data model by adding to each node a list of disjoint intervals or instants that represents the valid time. The valid time for a node is constrained to be a subset of the valid time for a node’s parent. We extend the XPath q...
متن کاملQuickXScan: Efficient Streaming XPath Evaluation
Many XML applications over the Internet favor high-performance single-pass streaming XPath evaluation. Finite automata-based algorithms suffer from potentially combinatorial explosion of dynamic states for matching descendant axes. We present QuickXScan for streaming evaluation of XPath queries containing child and descendant axes with complex predicates. Using a tree representation for an XPat...
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ژورنال
عنوان ژورنال: Journal of the ACM
سال: 2011
ISSN: 0004-5411,1557-735X
DOI: 10.1145/1989727.1989731