A Short Survey on P2P Data Indexing

P2P data indexing has recently attracted a great many research efforts. For various proposed schemes, there are generally two taxonomies: 1) From a systematic point of view, existing schemes fall into two categories: the over-DHT indexing paradigm, which as a layered manner, indexes data in DHT key space (i.e., over DHT), and the overlay-dependent indexing paradigm, which indexes data directly on a specific overlay. 2) From a viewpoint of indexing purpose, different schemes aim at supporting different query operators, like range queries, similarity queries, etc. Each query operator defines distinct semantic context and demands specific indexing scheme to fit it. At this point, we survey three subjects most relevant to P2P indexing: over-DHT indexing for various query types; several overlay-dependent indexing schemes (mainly for range queries); and finally a classic topic, DHT overlay. Here, only structured P2P is considered.