Keyphrases
- complex objects
- query language
- relational algebra
- database query languages
- data model
- expressive power
- relational calculus
- query evaluation
- object representations
- database
- object oriented
- relational model
- user defined
- relational data model
- path expressions
- computationally simple
- transitive closure
- conceptual model
- conjunctive queries
- constraint databases
- integrity constraints
- xml data
- training data
- database systems
- neural network