MXQuery - a low-footprint, extensible XQuery Engine

Overview

XQuery provides a very powerful, declarative environment to query and transform XML data.

Yet the complexity of the language requires a lot of effort and code to be correctly implemented. This prohibits the use of XQuery on devices with small computing power such as mobile phones or wireless sensor systems.

The declarative nature of XQuery is both a benefit and a drawback: While it allow very effective high-level data querying and manipulation, it works against the expectations of many application developers

The MXQuery project implements approaches to overcome these issues:

XQueryP is implemented to allow easier application development by extending the XQuery Update facility, which is also implemented in MXQuery.

The engine uses a very low memory footprint (both in code size and runtime data requirements) to be able to run on low-powered devices. This is achieved by using restricted type support, streaming data processing and a efficient token-based representation of XML.

Features

• XQuery 1.0 (currently about 95 % of the test suite workig)
• XQuery Update facility, uses file system as persistent storage
• XQueryP
• FORSEQ: Window semantics for XQuery
• Token-Based Storage model for low runtime overhead
• Streaming Execution
• Small executable size (80 KB for minimum version)
• Runnable on any Java platform (Minimum J2ME CLDC)

Publications and Theses

• Irina Botan, Peter M. Fischer, Daniela Florescu, Donald Kossmann, Tim Kraska, Rokas Tamosevicius: Extending XQuery with Window Functions, VLDB 2007
• Peter M. Fischer, Donald Kossmann, Tim Kraska, Rokas Tamosevicius: Windows for XQuery – Use Cases, Technical Report, ETH Zurich, Nov 2006
• Peter M. Fischer, David Graf, Donald Kossmann, Tim Kraska: Formal Semantics for Infinite XQuery. Available on request

Software

12.11.2007 Version 0.4.1 is on Sourceforge Compliance test results can be found here

25.9.2007 Version 0.4 is on Sourceforge Compliance test results can be found here

18.7. 2007 Version 0.3 is on Sourceforge. Compliance test results can be found here

People

• Peter Fischer
• Tim Kraska
• Rokas Tamosevicius
• Irina Botan
• Donald Kossmann
• Matthias Braun (Heidelberg)
• David Graf