Keyphrases
- query optimization
- sparql queries
- relational algebra
- query language
- linked data
- sql queries
- database systems
- cost model
- data model
- rewrite rules
- query processing
- complex queries
- distributed environment
- relational database systems
- rdf data
- semantic web
- query optimizer
- xml data
- database
- uniform manner
- object oriented
- case study
- databases
- query execution
- continuous queries
- database queries
- complex objects
- rdf graphs