Categorizing Efficient XML Compression Schemes

Web services are Extensible Markup Language (XML) applications mapped to programs, objects, databases, and comprehensive business functions. In essence, Web services transform XML documents into and out of information technology systems. XML has become the language of web services. Unfortunately, the structure of XML results in extremely verbose documents, often 3 times larger than ordinary content files. As XML becomes more common through Web services applications, its large file sizes increasingly burden the systems that must utilize it. XML compression addresses some of the problems of Web services via XML by reducing the size of XML documents transferred between a server and client, thereby conserving bandwidth and reducing user perceived latency. Although there is a wide variety of potential hardware/software solutions to remedy XML’s performance problems, many developers and researchers are resorting to a variety of tactics to improve the performance of XML processing and transmission. Many of these approaches simplify certain aspects of XML to reduce document size via compression, improve parser performance, and speed the mapping of XML document components to application objects (Schmelzer, 2002). This paper provides a qualitative overview of existing and proposed schemes for efficient XML compression, proposes three categories for relating XML compression scheme efficiency for Web services, and makes recommendations relating to efficient XML compression based on the proposed categories of XML documents. The goal of this paper is to aid the practitioner and Web services manager in understanding the impact of XML document size on Web services, and to aid them in selecting the most appropriate schemes for applications of XML compression for Web services.