Relational vs Similarity Selection
Relational selection is based on a boolean condition C
- evaluate C for each tuple t (or a likely subset of tuples)
- if C(t) is true, add t to result set
- if C(t) is false, t is not part of solution
- result is a set of tuples { t1, t2, ..., tn } all of which satisfy C
Uses for relational selection:
- precise matching on structured data
- using individual attributes with known, exact values
|