Keyphrases
- query optimization
- database systems
- query processing
- query optimizer
- cost model
- query execution plan
- database management systems
- multidatabase systems
- cost estimation
- storage structures
- query execution
- database
- query optimizers
- cardinality estimation
- data placement
- query scheduling
- query execution plans
- recursive queries
- r tree
- xml data
- selectivity estimation
- data management
- continuous queries
- join queries
- data types
- databases
- query plan
- efficient execution
- efficient processing
- relational database systems
- data model
- approximate query answering
- xml documents