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Computer Sciences Dept.

CICADA Project

Consistency in Currency-Aware Data Access

This is a project that is being conducted jointly with Phil Bernstein and Paul Larson at Microsoft Research. Increasingly, applications are using cached versions of data, even data that is stored in a DBMS. A familiar example is eBay, where several webpages show slightly out-of-date prices for items that are being bid on. Applications use their knowledge of when it is acceptable to use data that is not current in order to improve performance. However, by making copies outside the DBMS, they are forced to take on the responsibility of maintaining these caches, leading to more complex and error-prone application code. Our vision is to extend DBMS support for cached copies, allowing applications to be made simpler without sacrificing the efficiency gains of using copies when appropriate. The main idea is that applications should be able to specify whether a copy of a piece of data (e.g., a table, a row) can be used and how outdated that copy is allowed to be, as part of the SQL statement. The DBMS can exploit this information and use copies to improve performance as long as it guarantees that the application's currency requirements are met. The challenges to be addressed include query optimization and evaluation in the presence of cached copies, workload-aware cache maintenance, and concurrency control and serializability theory for transactions that can see stale data.


This project is funded by ????


Coming soon ...


Phil Bernstein (Microsoft Research)
Alan Fekete (University of Sydney)
Jonathan Goldstein (Microsoft Research)
Paul Larson (Microsoft Research)
Raghu Ramakrishnan (Computer Sciences, UW-Madison)

    Hongfei Guo (Computer Sciences, UW-Madison, Joined Microsoft Corp.)
    Pradeep Tamma (Computer Sciences, UW-Madison)



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