Patent ID: 8041706
Filing Date: 2011-10-18
Classification: G06F,Y10S

Abstract:
1. A method comprising: using a computer to process a query spanning a first database accessible by a first computer client and a second database accessible by a second computer client, the first database containing a first table containing a first set of values, and the second database containing a second table containing a second set of values; executing specific information-limiting protocols according to a query type to produce a query answer, wherein said protocols process equijoin queries, returning the query answer to the first computer client so that the first computer client learns from the query answer an intersection of the first set of values and the second set of values, and a cardinality of the second set of values; learning by the first computer client the distribution of duplicates in the second table; and revealing the query to the second computer client so that the second computer client learns from the query a cardinality of the first set of values.