XCQ: XML Compression and Querying System

We present our development of an XML compression and querying tool, which is called XML Compression and Querying System (XCQ). This system is developed based on a novel technique called DTD Tree and SAX Event Stream Parsing (DSP). This technique is designed for efficient compression of XML documents that conform to a given DTD without involving user expertise. A reasonable compression ratio, which is comparable to that of XMill, is achieved by DSP. The compressed documents in XCQ adopt a partitioned path-based data grouping which supports evaluating queries without running a full decompression. We demonstrate with examples how to query compressed documents in XCQ.