Patent ID: 7076507

Claim:
A system for storing a first plurality of tuples, each tuple comprising at least a first attribute having a first attribute value and a second attribute having a second attribute value, and a second plurality of tuples, each tuple comprising at least a first attribute, that is the same as the first attribute of the first plurality of tuples, having a first attribute value and a second attribute, different than the second attribute of the first plurality of tuples, having a second attribute value, the system comprising: a value store storing the first attribute values for each of the first and second plurality of tuples; a first instance store identifying instances of the first attribute value associated with each tuple in the first plurality of tuples; a second instance store identifying instances of the first attribute value associated with each tuple in the second plurality of tuples; a first cardinality store storing information representing frequencies of occurrence of instances of equal value of the first attribute in the first plurality of tuples, wherein a particular value in the value store associated with a particular instance in the first instance store can be derived using the first cardinality store; and a second cardinality store storing information representing frequencies of occurrence of instances of equal value of the first attribute in the second plurality of tuples, wherein a particular value in the value store associated with a particular instance in the second instance store can be derived using the second cardinality store.