Local matching algorithms: Summary
Multi-dimensional index structures
- do not work due to high dimensionality combined with incomplete subscriptions
Multiple one-dimension indexes
- search cost linear with the number of subscriptions
- Do not resists to event and subscription skew
Cost based multi-dimensional approach
- Exploits selectivity of predicate conjunctions
- sublinear, resist to event and subscription skew
- has to be improved when all predicates have weak filtering power