Fundamental access methods (reminder - conclusion)
Indexing
- need an order bw. indexed values (it does not mean an order bw. data blocs)
- logarithmic query and update costs (rather insensitive to data distribution)
- range queries allowed and easy
hashing
- no order needed (but data blocs are clustered accordingly)
- nearly constant query and update costs (very sensitive to data distribution)
- range queries, if compatible with hash function, not easy