Keyphrases
- query optimization
- database systems
- cost model
- query processing
- cost estimation
- cardinality estimation
- data placement
- xml data
- multidatabase systems
- semantic query optimization
- query execution
- query scheduling
- efficient execution
- relational databases
- selectivity estimation
- query plan
- query optimizers
- query execution plans
- query optimizer
- join queries
- execution plan
- virtual machine
- relational data
- data integration
- approximate query answering
- continuous queries
- xml databases
- keyword search
- query execution plan