CIS-X: A compacted indexing scheme for efficient query evaluation of XML documents

Some indexing and query evaluation methods have been proposed for accelerating query processing in XML documents. The structural summary approach reduces the portion of the XML to be scanned during query processing. However, most of the methods based on this approach cannot support complex queries efficiently and/or encounter a long index construction time and a huge index size. Many query processing methods focus on processing twig pattern matching and these have developed various structures to store intermediate results. The problem with these query processing methods include generating huge intermediate results, an expensive merging phase, complicated data structures, and a requirement to scan all potential nodes. This paper proposes a compacted index scheme for XML documents called CIS-X, which combines the advantages of the structural summary and query processing methods. The experimental results show that the CIS-X can resolve most of the above problems, and usually outperforms existing techniques.