[Please remove <h1>]
Winter 2003
Note: Events of interest to the Database Research Group
are posted to the uw.cs.database newsgroup and are mailed to the dbgroup
mailing lists: db-faculty (for DB group faculty), db-grads (for DB group
graduate students), and db-friends (for DB group alumni, visitors, and
friends). If you wish to subscribe to one of these lists, send mail to
majordomo@db
with "subscribe <list>" in the message body, where <list>
is the list you wish to subscribe to. For example, use "subscribe
db-friends" to subscribe to the db-friends list. To unsubscribe, send
"unsubscribe <list>" to the same address.
- DB group
meetings
- The DB group meets most Friday afternoons at 2pm, usually in DC1331.
See the list of current events for times and
locations of upcoming meetings. Each meeting lasts for an hour and
features an informal presentation by one of the members of the group.
Everyone is welcome to attend. These talks are intended to raise questions
and to stimulate discussion rather than being polished presentations
of research results. Speakers are determined using a rotating speaker
list, which can be found on the DB group meeting page
- DB seminar
series
- The DB seminar series features visiting speakers. These seminars are
more-or-less monthly, and are usually scheduled on Monday mornings
at 11am. See the list of current events for times
and locations of upcoming seminars. The full schedule can be found on
the DB seminar
series page.
Recent and Upcoming Events
| DB meeting:
: |
Friday, January 10th, 2:00
pm, DC1331 |
| Speaker:
: |
Hui Zhang |
| Topic: : |
Querying relational storage wrapped with XML views |
| Abstract: |
The rapid adoption of XML as a data exchange
format on the Web with the reality that a large portion of data is
still stored in relational tables requires many Web applications to
query relational data through XML views. In this talk, I will present
how to query relational storage wrapped with XML views by using our
Text/Relational query processing and optimization framework. However,
our focus is not on traditinoal view resolution issues. Instead, we focus
on how to develop query rewritings to translate an XQuery posed on XML
views to the SQL query that is formulated for relational data directly. |
| DB meeting:
: |
Friday, January 17th, 2:00
pm, DC1331 |
| Speaker:
: |
Ningyan Zhong |
| Topic: : |
Melody Constraint |
| Abstract: |
Content-based retrieval has been studied for
many years in many different forms of media. Now on internet
large volumn of music are stored in MP3 or MIDI format, which contribute
to a huge music database for us. A more natural way of searching a song
is by humming or singing, especially when people can not remember the title,
singer's name or even a little lyric, but a piece of melody of it. This
seminar is about how to represent melody so that such query is possible
and efficient. Currently, there exist two kinds of representation---contour-based
and interval-based, and they have been successfully applied in many music
systems, such as MELDEX, SEMEX. However, we propose a constraint-based
method, taking melody as a type of constraint, and we give a linear
time algorithm Reduce to find its canonical form. This representation is
as precise as interval-based method, but overcomes some problem of its redundant
searching. Another feature of constraint representation is, besides relative
interval information, "tonal context" (an important factor of music) is
taken into account. This feature makes it not only a good
candidate for building up an efficient music database system, but also
a potential tool for analyzing, understanding, and composing music by
computer. |
| DB meeting:
: |
Friday, January 24th, 2:00
pm, DC3314 |
| Speaker:
: |
Heechul Lim |
| Topic: : |
Evaluation of Disk-Based Shortest Path Algorithm |
Abstract:
|
Many solutions to find shortest paths
in large networks, such as road map of big city, are proposed recently,
due to the increasing use of GIS application. One of the promising solutions
is the disk-based shortest path algorithm, which doesn't require much
memory to find shortest paths in very large graph. The problem of
the algorithm is the processing time. This presentation will give
a possible solution to speed up the processing time while resources
using to execute the algorithm remains about the same.
|
| DB meeting:
: |
Friday, February 7th, 2:00
pm, DC1331 |
| Speaker:
: |
Amir Chinaei |
| Topic: : |
Access Control in OODB
|
Abstract:
|
This talk introduces some security techniques,
specifically concentrating on access control. We start with review of
access matrix to some recent models such as Role Based Access Control.
To the best of our knowledge, all existing models rely on a centralized
administration. Our research is taking steps to design a decentralized
access control system in which no one has administrative superiority, and
at the same time, all users’ documents are secure. This model exploits
some concepts of the RBAC model, XML structures, and object-oriented databases.
We eagerly anticipate your feedback.
|
| DB meeting:
: |
Friday, February 14th, 2:00
pm, DC1331 |
| Speaker:
: |
Grant Hutchison
|
| Topic: : |
Analysis and Survey of Java Data Objects
|
| DB meeting:
: |
Friday, February 28th, 2:00
pm, DC1331 |
| Speaker:
: |
Charlie Clarke
|
| Topic: : |
Using Structured and Unstructured Data for Open-Domain
Question Answering
|
| DB meeting:
: |
Friday, March 7th, 2:00
pm, DC1331 |
| Speaker:
: |
Lukasz Golab
|
| Topic: : |
Processing Joins in Continuous Queries Over Data Streams
|
Abstract:
|
We study sliding window multi-join processing
in continuous queries over data streams. Several algorithms are reported
for performing continuous, incremental joins, under the assumption that
all the sliding windows fit in main memory. The algorithms include multi-way
incremental nested loop joins (NLJs) and multi-way incremental hash joins.
We also propose join ordering heuristics to minimize the processing cost
per unit time. We test
a possible implementation of these algorithms and show that, as expected,
hash joins are faster than NLJs for performing equi-joins, and that the
overall processing cost is influenced by the strategies used to remove expired
tuples from the sliding windows.
This talk is based on a paper which may be found at
http://db.uwaterloo.ca/~ddbms/publications/stream/multijoins.pdf
|
| DB meeting:
: |
Friday, March 21st, 2:00
pm, DC1331 |
| Speaker:
: |
Dong Hui (Terry) Zhuo
|
| Topic: |
On Fine-Grained Access Control for XML
|
Abstract:
|
Fine-grained access control for XML is about
controlling access to XML documents at the granularity of individual elements
or attributes. This talk describes two problems related to the XML access
control. The first problem is the secure evaluation of XPath expressions.
While most of the existing XML access control mechanisms use a view-construction
technique, we developed a mechanism on the basis of query rewriting. A query
rewriting based mechanism might be more efficient in protecting large XML
documents against query based access. The second problem is how to provide
a compact representation of the access matrix. In order to speed up the
authorization decision making, most access control mechanisms choose to
materialize the access matrix. The fine-grained nature of XML access control,
however, makes the space cost of matrix materialization a significant issue.
Our experimental study shows that the access matrices, although large, are
very redundant. We proposed a code-book based technique that exploits this
redundancy, and we compare it to CAM, a recently proposed alternative solution
to the same problem.
|
| DB meeting:
|
Friday, March 28th, 2:00
pm, DC1331 |
| Speaker:
|
Robert Warren
|
| Topic: |
Record linkage for database integration
|
Abstract:
|
In this talk we introduce the problem of Record
Linkage which deals with identifying records from different databases referring
to the same entity. This problem is especially relevant to database
integration as no explicit information may be available to link their contents.
Basic record matching techniques will be outlined based on the work of
Newcombe and possible data integration issues identified. Current research
trends and methodologies will also be briefly reviewed.
|
| DB meeting: |
Friday, April 4th, 2:00
pm, DC1331 |
| Speaker:
|
Anil Goel
|
| Topic: |
I'll discuss some work done in the area of selectivity
estimation of LIKE predicates. In particular, I will describe, in detail,
a technique proposed by Krishnan, Vitter, and Iyer and, time permitting,
will talk about a simpler approach implemented by us for a reduced instance
of the same problem.
|
| DB meeting:
: |
Friday, April 11th, 2:00
pm, DC1331 |
| Speaker:
: |
Khuzaima Daudjee
|
| Topic: |
Lazy Database Replication With Freshness Guarantees
|
Abstract:
|
Lazy replication is a popular technique for improving
the performance and availability of database systems. Although there are concurrency
control techniques which guarantee
serializability in lazy replication systems, these techniques do not provide
freshness guarantees. Strong serializability avoids such problems, but
it is very costly to implement. We propose a generalized form of strong
serializability that is suitable for use with lazy replication. It
has many of the advantages of strong serializability, but can be implemented
more efficiently. We show how generalized strong serializability can be implemented
in a lazy replication system, and present the results of a simulation study
that quantifies the strengths and limitations of the approach.
|
| DB meeting:
: |
Friday, April 25th, 2:00
pm, DC1331 |
| Speaker:
: |
Glenn Paulley
|
| Topic: |
Overview of SQL Anywhere technologies
|
Abstract:
|
iAnywhere Solutions
, based in Waterloo, develops and markets Sybase SQL Anywhere, a full-featured
relational database product targetted at the small-to-medium sized business
marketplace. In this talk I'll give an overview of Sybase SQL Anywhere and
some of its underlying technologies, including aspects of: Adaptive Server
Anywhere, our database server; UltraLite, our "fingerprint-sized" main memory
database for handheld devices; and MobiLink and SQL Remote, our replication
technologies.
|
This page is maintained by Ken Salem.
