Keyphrases
- relational databases
- database
- relational database systems
- relational database management systems
- query processing
- object oriented
- query language
- high level query language
- query evaluation
- null values
- web search engines
- query formulation
- relational model
- databases
- database objects
- relational tables
- query logs
- relational data
- functional dependencies
- range queries
- complex queries
- statistical databases
- efficient processing
- xml data
- aggregate queries
- response time
- data sources
- normal form
- database queries
- user defined
- image retrieval
- information retrieval