Research Article
A Relation Routing Scheme for Distributed Semantic Media Query
Table 3
Comparison of distributed media query schemes.
| Scheme | Distributed database | Structural P2P network | Unstructured P2P network | Web search engine | RRS |
| Query description | Structural query language (e.g. SQL) | Set(s) of flat identifiers (e.g. DHT) | No limited the forms | Keywords plus Boolean operations | Prefix + semantic constraints | Query model | To query global view | To match structural mapping between identifier and location | Flooding, random walk, supernode routing, and so forth | To query the centrical indexes | Prefix-based routing | Adaptable to dynamic sources | Poor | Good | Very good | Poor | Very good | The optimality of transmission path | Poor | Poor | Poor | Poor | Very good | Acquisition directivity | Good | Very good | Poor | Very good | Very good | Search capability | Stronger | Weak | Rely on the matching capability of forwarding nodes | Normal | Stronger |
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