Keyphrases
- query optimization
- xml data
- xml documents
- cost model
- xml databases
- xml queries
- query processing
- database systems
- data model
- xml schema
- relational databases
- efficient query processing
- multidatabase systems
- cardinality estimation
- semi structured data
- query execution
- query optimizer
- keyword search
- cost estimation
- query processing and optimization
- efficient execution
- metadata
- xpath queries
- approximate query answering
- recursive queries
- data exchange
- query evaluation
- relational database systems
- selectivity estimation
- semantic query optimization
- query language
- continuous queries
- path expressions
- query optimizers
- query scheduling
- query result
- query rewriting
- data types
- storage structures
- database