Source Access Limitations
Sources can have a variety of access limitations
- Form interfaced databases may require certain attributes to be bound
- Whitepages may require the name of the person
- To get the numbers of a set of n people, we will have to access the source n times
- and may be unable to handle bindings of other attributes
- A Whitepages database may not take the address of a person as a bound attribute
- To get the number of John Doe, who lives on Lemon St, we will have to get the numbers of all John Does, and locally filter the ones not living on Lemon Street
- Wrapped web-pages cannot select over any attributes