CHAPTER 14 Parallel Strategy r s 1 := SELECT FROM WHERE Protecting Data in Outsourcing Scenarios Sequential Strategy 375 tid, F e 1 Name 1 r s 1 := SELECT FROM WHERE tid, Name 1 F e 1 Diagnosis = `Diabetes' tid, Name 2 F e 2 County = `Napa' AND tid IN {4,6} Name 1 Name 2 AS Name r s 1 JOIN r s 2 ON r s 1 .tid = r s 2 .tid Diagnosis = `Diabetes' tid, Name 2 F e 2 County = `Napa' Name 1 Name 2 AS Name r s 1 JOIN r s 2 ON r s 1 .tid = r s 2 .tid r c := r s 2 := r s 2 := SELECT FROM WHERE SELECT FROM WHERE r c := SELECT FROM SELECT FROM FIGURE 14-9 An example of query translation in the non-communicating servers scenario. 14.3.3. Multiple Fragments The main limitation of the solution in Ref. [26] is that it relies on the absence of communication between the two storage servers. This assump- that form a confidentiality constraint. The sec- ond condition states that the fragments must be disjoint. In this way, the fragments composing a fragmentation can be stored at the same external