Hongfei Guo

I am a sixth year PhD student in Database Group, Computer Sciences Department at University of Wisconsin-Madison. Before coming to beautiful UW, I studied Computer Science at Peking University, one of the best science and literature universities in China, receiving my M.S. and B.S. in 1999 and 1996 respectively.

Contact

Bio

Research

Research Projects

CICADA (Consistency In Currency-Aware Data Access)
This is a joint work with Per-Åke (Paul) Larson and Jonathan Goldstein at Microsoft Research. Many application systems today make use of various forms of asynchronously updated replicas to improve scalability, availability and performance. If an application uses replicas that are not in sync with source data, it is clearly willing to accept results that are not completely current, but typically with some limits on how stale the data can be. Today such requirements are not explicitly declared anywhere; they can only be inferred from the properties of the replicas used. Because requirements are not explicit, the system cannot detect when they are not met and take appropriate action. Instead, data currency requirements are implicitly expressed in the application logic through the choice of data sources for queries. This very much resembles the situation in the early days of database systems when programmers had to choose what indexes to use and how to join records. 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. Our approaches are three-fold:
- Expressing "Good Enough" in SQL: The main idea is to extend SQL to allow applications to explicitly specify currency and consistency (C&C) constraints. We developed a model for C&C constraints and defined their semantics rigorously, thereby providing correctness standards for the use of replicated and cached data.
- Enforcing "Good Enough" : The main idea is to integrate C&C checking into cost-based query optimization and execution. We showcased how it can be done in Microsoft SQL Server for a simple case where each view in the cache is copied from a snapshot of the backend database.
- Fine-grain "Good enough" Database Caching Model : How do we decide if cached data can be used to answer a query with C&C constraints? We develop a flexible cache model in which cache properties, such as consistency, can be maintained at the granularity of partitions of a view. Specifications of what partitions to cache and what properties to maintain for cached partitions amount to a design for the cache database, and the design can have a significant impact on the effectiveness of the cache. We formally define four fundamental properties of cached data: presence, consistency, completeness and currency. We study cache design in terms of these properties, and identify conditions under which efficient non-cascading maintenance techniques can be used. We also develop techniques for C&C checking in query optimization and execution.
- Adaptive "Good Enough" Database Caching : How can the cache adaptively adjust its "Good Enough" standard? We plan to investigate C&C-aware cache replacement and refresh policies, such that the cache can make decisions adaptively to workload with relaxed C&C constraints.
Phoenix: Efficiently Indexing One-Dimensional Intervals
Scalability is a challenge facing real-world information dissemination systems: they need to handle millions of daily incoming documents for millions of registered subscriptions. Furthermore, these subscriptions are not static -they are added and deleted frequently. Driven by the current technology trends, where the gap between disk speed and CPU speed keeps increasing and the price of disks keeps dropping, we investigate in the project how to use deferred updates for dynamic maintenance of complex index structures.

Publications Entry@DBLP

Doctoral Dissertation: "Good Enough" Database Caching, Hongfei Guo, University of Wisconsin - Madison (August 2005)

Conference Publications

Caching with "Good Enough" Currency, Consistency, and Completeness
Hongfei Guo, Per-Åke Larson, Raghu Ramakrishnan
To appear in Proceedings of the 31st International Conference on Very Large Data Bases (VLDB 2005),
Trondheim, Norway, September 2005.

Relaxed Currency and Consistency: How to Say "Good Enough" in SQL
Hongfei Guo, Per-Åke Larson, Raghu Ramakrishnan, Jonathan Goldstein
In Proceedings of the 2004 ACM SIGMOD International Conference on Management of Data (SIGMOD 2004),
pages 815-826, Paris, France, June 2004

Quality of service evaluations of multicast streaming protocols
Haonan Tan, Derek L. Eager, Mary K. Vernon, Hongfei Guo
In Proceedings of the 2002 ACM SIGMETRICS International Conference on Measurement and Modeling of Computer Systems (SIGMETRICS 2002) ,
pages 183-194 Marina del Rey, CA, June 2002.

Demonstrations

Support for Relaxed Currency and Consistency Constraints in MTCache
Hongfei Guo, Per-Åke Larson, Raghu Ramakrishnan, Jonathan Goldstein
In Proceedings of the 2004 ACM SIGMOD International Conference on Management of Data (SIGMOD 2004),
pages 937-938, Paris, France, June 2004.

Non-Refereed Invited Work

MTCache: A Transparent Database Cache for SQL Server
Per-Åke Larson, Jonathan Goldstein, Hongfei Guo, and Jingren Zhou
In IEEE Data Engineering Bulletin 27(2): 35-40 (2004)

Technical Reports

Caching with "Good Enough" Currency, Consistency, and Completeness
Hongfei Guo, Per-Åke Larson, Raghu Ramakrishnan
Technical Report, TR1520, University of Wisconsin-Madison, Feb 2005

Selected Awards

Microsoft Graduate Fellowship, UW-Madison, 2001 - 2002
LianXiang scholarship, Peking Univ., 1998
Guanghua & Antai Scholarship, Peking Univ., 1995, 1993
Honglou Scholarship for Excellence in Arts, Peking Univ., 1993

Intern Experience

Research Intern, mentored by Per-Åke (Paul) Larson in the Database Group at Microsoft Research. (Fall and Summer 2003)
A typical e-commerce site such as eBay makes frequent use of replicated and cached data. When browsing auctions in a category, the data (e.g., item prices, number of bids) may be a little out of date. However, most users understand and accept this, as long as the page they see when they click on an individual auction is completely current. We propose that applications make the requirements known to the DBMS through explicit currency and consistency (C&C) constraints in queries and have developed mechanisms to guarantee that the constraints are satisfied. I designed and implemented a prototype in the MTCache framework (built on the code base of SQL Server) that supports queries with relaxed C&C constraints.
Research Intern, mentored by Per-Åke (Paul) Larson in the Database Group at Microsoft Research. (Summer 2001)
I worked on RECYCLE project, a research on query results caching. In order to make decision on cache replacement, workload statistics has to be maintained properly and efficiently. I designed and implemented a module to estimate and maintain statistics of update workload.
Software Design Engineer Intern, mentored by Oliver Seeliger in the WebData Group, Microsoft. (Summer 2000)
Designed and implemented Schema Generator, part of SQLXML, which takes an annotated schema file in XML format as input, and generates relational database schemas for it with proper integrity constraints.

Teaching Assistantship

CS640: Introduction to Computer Networks (Spring 2001)
CS367: Introduction to Data Structures (Fall 2000)
CS302: Introduction to Introduction to Programming (Spring 2000)
CS354: Machine Organization and Programming (Fall 1999)

CS Courses

Selected Course Projects
- CS731 Project: Implementation and Evaluation of Exact and Approximate Dynamic Bayesian Network Inference Algorithms
- CS747 Project: Analytic Evaluation of Quality of Service for On-Demand Data Delivery
- CS736 Project: An In-Depth Examination of Java I/O Performance and Possible Tuning Strategies
- CS764 Project: Adding Email Type into a Commercial Object-Oriented Relational Database -- TOR
- CS752 Project: Software-based and Hardware-based Branch Prediction Strategies and Performance Evaluation
Courses Taken from Computer Sciences Department

CS731: Advanced Artificial Intelligence) (Prof. C. David Page, Spring 2001)
CS784: Data Models and Languages (Formal Topics in Databases) (Prof. Raghu Ramakrishnan, Spring 2000)
CS747: Advanced Computer System Performance Modeling (Prof. Mary Vernon, Spring 2000)
CS736: Advanced Operating Systems (Prof. Remzi Arpaci-Dusseau, Fall 2000)
CS540: Introduction to Artificial Intelligence (Prof. Jude W. Shavlik, Fall 2000)
CS764: Topics in Database Management Systems (Prof. Jeffrey F. Naughton, Spring 1999)
CS564: Database Management Systems: Design and Implementation (Prof. David J. DeWitt, Spring 1999)
CS640: Introduction to Computer Networks (Prof. Lawrence H. Landweber, Fall 1999)
CS752: Advanced Computer Architecture I (Prof. Mark D. Hill, Fall 1999)

Minor Courses

Minor Courses Taken from School of Business
- OIM750: Operations Management (Prof. James A. Rappold, Fall 2002)
- Finance700: Introduction to Financial Management (Prof. Bulent Paker, Spring 2001)
- Acct700: Financial Accounting (Prof. John J. Wild, Fall 2001)
- Marketing700: Marketing Management (Prof. Jan B. Heide, Fall 2001)

Dance

Selected Dance Performance
- University of Wisconsin Artists of the Future, Sep. 20, 2004, Overture Center for the Arts Grand Opening Festival, Madison, WI [Review from The Capital Times]
- Dance Program Spring Concert, April 22-24, 2004, Margaret H'Doubler Performance Space, Madison, WI
- CSSA Chinese New Year Talent Show, Jan. 25th, 2004, Union Theater, Madison, WI. [photos]
- CSSA Chinese New Year Talent Show, Feb. 11th, 2002, Union Theater, Madison, WI. [photos]
- Madison Friends of International Students Fund Raising Talent Show, May 2003, Madison, WI.
- Madison Friends of International Students Fund Raising Talent Show, May 2001, Madison, WI.
Selected Dance Critiques and Journals
- Art in My Eyes (April 2004)
Dance Courses Taken from Dance Program Department
- Dance211: Modern Dance Technique III (Ms. Collette Stewards, Spring 2003)
- Dance112: Modern Dance Technique II (Prof. Barbara Grubel, Spring 2002)
- Dance111: Modern Dance Technique I (Prof. Claudia A. Melrose, Fall 1999)
- Dance125: Ballet Technique I (Ms. Marlene Skog, Spring 2003)
- Dance22: Ballet II (Mr. Vivian Tomlinson, Fall 2002)
- Dance22: Ballet II (Mr. Vivian Tomlinson, Spring 2001)
- Dance22: Ballet II (Mr. Vivian Tomlinson, Fall 2001)
- Dance32: Modern Jazz Dance II (Ms. Phyllis Sanfilippo, Fall 2002)
- Dance031: Modern Jazz Dance I (Ms. Phyllis Sanfilippo, Fall 2000)
- Dance001: Chinese Opera Dance (Prof. Jin-Wen Yu, Fall 2001)
- Dance452: Dance Repertory Theater (Prof. Jin-Wen Yu, Fall 1999)

Last updated: Friday May 20, 2005