Gregory Todd Williams SPARQL BGP Optimization Presentation Shangguan 1
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- Question is for the Presentation: Gregory Todd Williams SPARQL BGP Optimization Presentation
- Question is asked by: Zhenning Shangguan
- The Question is: In section 4.1, it is stated that "Triple pattern components may be bound (i.e. concrete)" or unbound (i.e. variable)... The case of unbound components is trivial as they do not affect the required statistics." Why?
- Answer: An unbound node in a triple pattern will have a selectivity of 1 (a variable matches all possible values in the data). If all nodes are variables, the pattern selectivity will be 1, otherwise the selectivity is based only on the bound terms in the pattern.
Bound v.s. Unbound. In section 4.1, it is stated that "Triple pattern components may be bound (i.e. concrete)" or unbound (i.e. variable)... The case of unbound components is trivial as they do not affect the required statistics." Why?
Facts about Gregory Todd Williams SPARQL BGP Optimization Presentation Shangguan 1RDF feed
| Answer | An unbound node in a triple pattern will h … An unbound node in a triple pattern will have a selectivity of 1 (a variable matches all possible values in the data). If all nodes are variables, the pattern selectivity will be 1, otherwise the selectivity is based only on the bound terms in the pattern. ed only on the bound terms in the pattern. |
| Question asked | In section 4.1, it is stated that "Triple pattern components may be bound (i.e. concrete)" or unbound (i.e. variable)... The case of unbound components is trivial as they do not affect the required statistics." Why? |
| Question asked by | Zhenning Shangguan + |
| Question for the Presentation | Gregory Todd Williams SPARQL BGP Optimization Presentation + |
