Keyphrases
- query optimization
- cost model
- database systems
- query processing
- multidatabase systems
- xml data
- query execution
- cost estimation
- cardinality estimation
- data placement
- query optimizer
- query scheduling
- efficient execution
- semantic query optimization
- recursive queries
- query execution plan
- approximate query answering
- execution plan
- query execution plans
- spatial join
- join algorithms
- relational databases