Abstract
As XML technologies have undoubtedly become a standard for data representation, it is inevitable to provide efficient implementations of W3C recommendations. A possible optimization of particular types of techniques can be found in exploitation of similarity of XML data and/or matching of XML patterns.
In this paper we provide an overview and classification of such techniques from various points of view. We briefly describe the best known representatives of particular ideas and we discuss their key advantages and disadvantages.
The text should serve as a good starting point for proposing an appropriate similarity-based optimization.