Description

The techniques other than generalization of quasi-identifier and suppression of records. For example, instead of suppressing a whole record, one can hide some sensitive attributes of the record; one advantage is that the number of records in the anonymized table is accurate, which may be useful in some applications. The Conditional functional dependencies(CFDs), that are capable of capturing the notion of “correct data” in these situations. We used CFDs that represent real-world constraints such as (a) zip codes determine states, (b) zip codes and cities determines states (a city by itself does not suffice since many states have cities with the same name), (c) states and salary bracket determine tax rates (a tax rate depends on both the state and employee salary),etc. CFDs aim at capturing the consistency of data by incorporating bindings of semantically related values. Another possible technique is to generalize a sensitive attribute value, rather than hiding it completely. An interesting question is how to effectively combine these techniques with generalization and suppression to achieve better data quality. There are two alternative evaluation strategies for the SQL detection queries. Key distinction between these strategies is how we evaluate the where clauses in each detection query. Attribute disclosure can occur with or without identity disclosure. It has been recognized that even disclosure of false attribute information may cause harm . An observer of a released table may incorrectly perceive that an individual’s sensitive attribute takes a particular value and behaves accordingly based on the perception. This can harm the individual, even if the perception is incorrect. XML is commonly supported by SQL database systems. However, existing mappings of XML to tables can only deliver satisfactory query performance for limited use cases. In this paper, we propose a novel mapping of XML data into one wide table whose columns are sparsely populated. This mapping provides good performance for document types and queries that are observed in enterprise applications but are not supported efficiently by existing work. XML queries are evaluated by translating them into SQL queries over the wide sparsely-populated table. Mapping nested elements to flattened tables is the key problem for supporting XML on SQL databases. Many mapping schemes have been proposed to decompose nested structures into normalized tables.