Consistent Query Plan Generation in Secure Cooperative Data Access

Abstract

In this paper, we consider restricted data sharing between a set of parties that wish to provide some set of online services requiring such data sharing. We assume that each party stores its data in private relational databases, and is given a set of mutually agreed set of authorization rules that may involve joins over relations owned by one or more parties. Although the query planning problem in such an environment is similar to the one for distributed databases, the access restrictions introduce significant additional complexity that we address in this paper. We examine the problem of efficiently enforcing rules and generating query execution plans in this environment. Because of the exponential complexity of optimal query planning, our query planning algorithm is heuristics based but produces excellent, if not optimal, results in most of the practical cases.

Minimum cost rule enforcement for cooperative database access

“…We note that our current (new) algorithm is more thorough than the algorithm in [16]. That algorithm only considers rules at level n − 1 (instead of levels n − 1 and n − 2).…”

“…For each subquery, we ideally want an optimal plan, i.e., a plan with smallest overhead of data transmission among parties and joins at a party. We have examined this problem in [16] where we proposed a fast heuristic algorithm, since the problem of optimal query planning is not only NPhard (as in traditional query planning literature) but also substantially more complicated because of the possibilities of exchange of partial results among parties.…”

“…In this paper we seek a single combined enforcement and query planning algorithm instead of the two different ones studied in [14] and [16]. For this, we consider the rules as queries also -which they are.…”

Towards Collaborative Query Planning in Multi-party Database Networks

“…Significant effort has been made to protect data confidentiality in mutli-party database networks by enforcing data authorization policies [3,8,9,14]. Previous work has also proposed new query engines that consider query information confidentiality during collaborative query execution [4][5][6].…”