rhoIndex – Designing and Evaluating an Indexing Structure for Graph Structured Data

An own design of an indexing structure for general graph structured data called -index that allows an effective processing of special path queries is presented. These special queries represent for example a search for all paths lying between two arbitrary vertices limited to a certain path length. The -index is a multilevel balanced tree structure where each node is created with a certain graph transformation and described by modified adjacency matrix. Hence, -index indexes all the paths to a predefined length l inclusive. The search algorithm is then able to find all the paths shorter than or having the length l and some of the paths longer then the predefined l lying between any two vertices in the indexed graph. The designed search algorithm exploits a special graph structure, a transcription graph, to compute the result using the -index . We also present an experimental evaluation of the process of creating the -index on graphs with different sizes and also a complexity evaluation of the search algorithm that uses the -index.