Current Support of XML by the "Big Three"

XML technologies have undoubtedly become a standard for data representation and manipulation. Thus it is inevitable to propose and implement efficient techniques for managing and processing XML data. A natural alternative is to exploit tools and functions offered by relational database systems. Even though the native XML databases are undoubtedly more efficient, relational databases are still more popular among XML users due to their long history, maturity and reliability. In this paper we provide an overview of XML-processing functions that are currently supported by the so-called "Big Three", i.e. Oracle 11g, IBM DB2 9, and Microsoft SQL Server 2008. We firstly show what are the key aspects a user may require from an XMLenabled database. Then, we provide an overview of their support in the respective systems. And, finally, we compare and contrast the findings so that advantages and disadvantages of the particular systems are apparent.