Abstract. The W3C recently released the XQuery Update Facility 1.0, a Candidate Recommendation for an XML update language. It appears likely that this proposal will become standard. XQuery has been equipped with a formal semantics and sound type system, but there has been little work on static analysis or typechecking of XML updates, and the typing rules in the current W3C proposal are unsound for "transform" queries that perform embedded updates. In this paper, we investigate the problem of schema alteration, or synthesizing an output schema describing the result of an update applied to a given input schema. We review regular expression type systems for XQuery, present a core language and semantics for W3C-style XML updates, and develop an effect analysis, schema alteration, and sound typing rules for updates and "transform" queries.
A semantics for XQuery Updates has been defined by Benedikt and Cheney in REF .
Semantics, types and effects for XML updates
In DBPL
Computer Science