XML fragments extended with database operators

XML documents represent a middle range between unstructured data such as textual documents and fully structured data encoded in databases. Typically, information retrieval techniques are used to support search on the “unstructured ” end of this scale, while database techniques are used for the structured part. To date, most of the works on XML query and search have stemmed from the structured side and are strongly inspired by database techniques. In a previous work we described a new query approach via pieces of XML data called “XML Fragments ” which are of the same nature as the queried XML documents and are specifically targeted to support the information needs of end-users in an intuitive way. In addition to its simplicity, XML Fragments represent a natural extension to traditional free text information retrieval queries where both documents and queries are represented as vectors of words and as such it enables a natural extension of IR ranking models to rank XML documents by context and structure. In this paper, we extend XML Fragments with database operators thus allowing both IR style approach together with database “structured ” query capabilities.