Horizontal Decompositions (Contd.)
Suppose that contracts with value > 10000 are subject to different rules. This means that queries on Contracts will often contain the condition val�.
One way to deal with this is to build a clustered B+ tree index on the val field of Contracts.
A second approach is to replace contracts by two new relations: LargeContracts and SmallContracts, with the same attributes (CSJDPQV).
- Performs like index on such queries, but no index overhead.
- Can build clustered indexes on other attributes, in addition!