org.deri.iris.facts
Interface IDataSource

public interface IDataSource

Interface for pluggable datasources for iris.

Author:

Richard P??ttler (richard dot poettler at deri dot at)

Method Summary

void	get(IPredicate p, ITuple from, ITuple to, IRelation r) Retrieves some tuples for a given predicate from the data source and adds it to a given relation.

Method Detail

get

void get(IPredicate p,
         ITuple from,
         ITuple to,
         IRelation r)

Retrieves some tuples for a given predicate from the data source and adds it to a given relation.

The terms in from and to set the lower and upper bounds for the terms in the corresponding columns of the tuples, which should be added to the tuple collection. null in the from or to list, stands for the smallest, respectively biggest possible term for this column.

Parameters:

p - the predicate for which to retrieve the tuples (because one data source might hold tuples for multiple predicates)

from - the lower bound for the tuples which should be added to the relation (null is equivalent to a tuple containing only nulls)

to - the upper bound for the tuples which should be added to the relation (null is equivalent to a tuple containing only nulls)

r - the relation where to add the tuples