非递归XQuery和复值函数式查询语言的复杂性
On the Complexity of Nonrecursive XQuery and Functional Query Languages on Complex Values
摘要：
本文研究了函数式查询语言对复杂值（如单子代数和XQuery的无递归片段）求值的复杂性。证明了等式限制于原子值的单子代数对于线性指数时间内可解且交替数为线性的问题类TA[2^{O（n）}，O（n）]是完备的.对于非确定指数时间，具有原子值相等但无否定的单子代数的单调片段是完全的。对于具有深等式的单子代数，我们建立了TA[2^{O（n）}，O（n）]的下界和指数空间上界.然后，我们研究了XQuery的一个片段Core XQuery，它似乎包含了传统上被认为是必不可少的复杂值查询语言的所有特性。单子代数列表和核心XQuery（与“孩子”作为唯一的轴）之间的密切联系被展出，它表明，这些语言是表达等价的表示问题。我们证明了Core XQuery和monad代数w.r.t.一样难。组合复杂度，并且如果假设查询是固定的，则它在TC 0中。
英文摘要：
This paper studies the complexity of evaluating functional query languages for complex values such as monad algebra and the recursion-free fragment of XQuery. We show that monad algebra with equality restricted to atomic values is complete for the class TA[2^{O(n)}, O(n)] of problems solvable in linear exponential time with a linear number of alternations. The monotone fragment of monad algebra with atomic value equality but without negation is complete for nondeterministic exponential time. For monad algebra with deep equality, we establish TA[2^{O(n)}, O(n)] lower and exponential-space upper bounds. Then we study a fragment of XQuery, Core XQuery, that seems to incorporate all the features of a query language on complex values that are traditionally deemed essential. A close connection between monad algebra on lists and Core XQuery (with ``child'' as the only axis) is exhibited, and it is shown that these languages are expressively equivalent up to representation issues. We show that Core XQuery is just as hard as monad algebra w.r.t. combined complexity, and that it is in TC0 if the query is assumed fixed.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
