bluuebunny/crossref_metadata_2025 huggingface dataset:
Research in databases and data-intensive applications
Authors: König-Ries Brigitta , Lockermann Peter C.
Published: November 2005

The future world of computing will be governed by large networks of communicating and interacting persons and machines, geographic mobility, temporary attachment to networks, the disintegration of formerly monolithic organizations and systems into autonomously acting units, the substitution of cooperation regimes for centralized control, and an ever-increasing spectrum of ever more ambitious applications. In such a world the methods, techniques and tools of database technology will play new and more diversified roles, not so much in combination as parts of all-inclusive database systems but rather individually as indispensable ingredients of or desirable enhancements to novel communication, control and application systems. The two information systems groups whose work is presented in this report aim at meeting these new challenges. Our contributions are in the large field of what we call “distributed data-intensive applications”.
Extension decision
Authors: Sun Bo , Chen Julong
Published: November 2005

On the viewpoint of system theory, this paper expounds connotations and characteristics about extension decision applied branch of extension science, introduces operation sequences, techniques and methods on extension decision, points out its working achievement and the direction in its development.
Issues essential to World Wide Web marketing
Authors: Stratton A. Maurice , Wong Ka-Wing
Published: November 2005

Technological society in the 21st century gives us a new meaning and a new challenge in our daily life. In marketing, the challenge comes in the use of technology to make business successful. With the Internet replacing many traditional communication mediums, marketing on the World Wide Web is going to be the biggest challenge to most marketers. This paper discusses the issues that are essential to marketing on the World Wide Web.
Extension relational algebra and Grey relational algebra
Authors: Wong Ka-Wing
Published: November 2005

This paper discusses integrating two uncertainty systems (the extension set theory and the grey system theory) into the classical relational algebra. The results of the integration are the extension relational algebra and the grey relational algebra.
PC note
Authors: Styer Eugene
Published: November 2005

Now in segment nine we look at memory, video, and the PC bus. This is a bit more than I had planned, but with the changes coming up in SIGICE, I want to finish the remaining topics.
Integrating dynamically-fetched external information into a DBMS for semistructured data
Authors: McHugh Jason , Widom Jennifer
Published: November 2005

We describe the
external data manager
component of the
Lore
database system for semistructured data. Lore's external data manager enables dynamic retrieval and integration of data from arbitrary, heterogeneous external sources during query processing. The distinction between Lore-resident and external data is invisible to the user. We introduce a flexible notion of
arguments
that limits the amount of data fetched from an external source, and we have incorporated optimizations to reduce the number of calls to an external source.
Extracting entity profiles from semistructured information spaces
Authors: Nado Robert A. , Huffman Scott B.
Published: November 2005

A semistructured information space consists of multiple collections of textual documents containing fielded or tagged sections. The space can be highly heterogeneous, because each collection has its own schema, and there are no enforced keys or formats for data items across collections. Thus, structured methods like SQL cannot be easily employed, and users often must make do with only full-text search. In this paper, we describe an approach that provides structured querying for particular types of
entities
, such as companies and people. Entity-based retrieval is enabled by
normalizing
entity references in a heuristic, type-dependent manner. The approach can be used to retrieve documents and can also be used to construct entity profiles — summaries of commonly sought information about an entity based on the documents' content. The approach requires only a modest amount of meta-information about the source collections, much of which is derived automatically.
Report on the second IEEE metadata conference (Metadata '97)
Authors: Musick Ron , Miller Chris
Published: November 2005

On September 15th and 16th, 1997 the Second IEEE Metadata Conference was held at the National Oceanic and Atmospheric Administration (NOAA) complex in Silver Spring, Maryland. The main objectives of this conference series are to provide a forum to address metadata issues faced by various communities, promote the interchange of ideas on common technologies and standards related to metadata, and facilitate the development and usage of metadata. Metadata'97 met these objectives, drawing about 280 registered attendees from ten different countries and over one hundred different institutions. The audience included scientists, information technology specialists, and librarians from communities as widespread as finance, climatology, and mass storage. The technical program included two keynote addresses, two panel presentations, as well as twenty-three papers and thirteen posters selected from over one hundred abstracts. We provide highlights of the conference below. For more details, the proceedings are available electronically from the conference homepage at: http://www.llnl.gov/liv_comp/metadata/md97.html.The keynote addresses were "An Architecture for Metadata: The Dublin Core, and why you don't have to like it" by Stuart Weibel, OCLC, and "The Microsoft Repository" by Philip Bernstein, Microsoft.Weibel's talk described the Dublin core and the Warwick framework - a series of workshops whose output has been a core set of metadata elements common to data from most domains, along with a "container" based mechanism for plugging in larger domain-specific sets of metadata, like the FGDC's standard for geospatial metadata. These efforts represent two of the defining works in this community. Weibel touched on the history of this effort and described his belief that standards such as RDF (resource description framework) for the WWW coming from organizations like the World Wide Web Consortium (W3C) will have a major influence on the metadata community in the near future.Bernstein's talk covered the Microsoft Object Repository, which also has the potential for a large impact on what metadata gets stored and how they are managed. Bernstein describes the repository as "a place to persist COM objects" (component object model), and as more than just a object-oriented database. The features of a true repository are 1) objects and properties, 2) rich relational semantics, 3) extensibility, and 4) versioning. Repositories are used to help tools interoperate by storing predefined "information models". The information models are the metadata used to describe the underlying COM objects in a standard way such that the objects can be shared across tool boundaries. The main consumers of this type of technology are tool vendors.
Workflow history management
Authors: Koksal Pinar , Arpinar Sena Nural , Dogac Asuman
Published: November 2005

A workflow history manager maintains the information essential for workflow monitoring and data mining as well as for recovery and authorization purposes.Certain characteristics of workflow systems like the necessity to run these systems on heterogeneous, autonomous and distributed environments and the nature of data, prevent history management in workflows to be handled by the classical data management techniques like distributed DBMSs. We further demonstrate that multi-database query processing techniques are also not appropriate for the problem at hand.In this paper, we describe history management, i.e., the structure of the history and querying of the history, in a fully distributed workflow architecture realized in conformance with Object Management Architecture (OMA) of OMG. By fully distributed architecture we mean that the scheduler of the workflow system is distributed and in accordance with this, the history objects related with activities are stored on data repositories (like DBMSs, files) available at the sites involved. We describe the structure of the history objects determined according to the nature of the data and the processing needs, and the possible query processing strategies on these objects using the Object Query Service of OMG. We then present the comparison of these strategies according to a cost model developed.
Where will object technology drive data administration?
Authors: Rosenthal Arnon
Published: November 2005

Several unifications that the application development process has long needed are now occurring, due to developments in object technologies and standards. These will (gradually) change the way data intensive applications are developed, reduce databases' prominence in this process, and change data administration's goals and participants. At the same time, the database community needs to ensure that its experiences are leveraged and its concerns are met within the new methodologies and toolsets. We discuss these issues, and illustrate how they apply to a portion of the Department of Defense (DOD). We also examine things that object technology won't accomplish, and identify research problems whose solution would enable further progress.
Towards on-line analytical mining in large databases
Authors: Han Jiawei
Published: November 2005

Great efforts have been paid in the Intelligent Database Systems Research Lab for the research and development of efficient data mining methods and construction of on-line analytical data mining systems.Our work has been focused on the integration of data mining and OLAP technologies and the development of scalable, integrated, and multiple data mining functions. A data mining system, DBMiner, has been developed for interactive mining of multiple-level knowledge in large relational databases and data warehouses. The system implements a wide spectrum of data mining functions, including characterization, comparison, association, classification, prediction, and clustering. It also builds up a user-friendly, interactive data mining environment and a set of knowledge visualization tools. In-depth research has been performed on the efficiency and scalability of data mining methods. Moreover, the research has been extended to spatial data mining, multimedia data mining, text mining, and Web mining with several new data mining system prototypes constructed or under construction, including GeoMiner, MultiMediaMiner, and WebLogMiner.This article summarizes our research and development activities in the last several years and shares our experiences and lessons with the readers.
Active message logical routing verification
Authors: Wong Ka-Wing
Published: November 2005

This paper presents a system that can be used to verify properties of intelligent agents automatically. We use verification of active message logical routing as an example to illustrate the verification approach. The system can be used to verify intelligent agents in general. The system uses branching time temporal logic as foundation and employs a set of axioms, lemmas, and theorems that we developed to verify logical routing properties of active messages.
Parallel mining algorithms for generalized association rules with classification hierarchy
Authors: Shintani Takahiko , Kitsuregawa Masaru
Published: November 2005

Association rule mining recently attracted strong attention. Usually, the classification hierarchy over the data items is available. Users are interested in generalized association rules that span different levels of the hierarchy, since sometimes more interesting rules can be derived by taking the hierarchy into account.

In this paper, we propose the new parallel algorithms for mining association rules with classification hierarchy on a shared-nothing parallel machine to improve its performance. Our algorithms partition the candidate itemsets over the processors, which exploits the aggregate memory of the system effectively. If the candidate itemsets are partitioned without considering classification hierarchy, both the items and its all the ancestor items have to be transmitted, that causes prohibitively large amount of communications. Our method minimizes interprocessor communication by considering the hierarchy. Moreover, in our algorithm, the available memory space is fully utilized by identifying the frequently occurring candidate itemsets and copying them over all the processors, through which frequent itemsets can be processed locally without any communication. Thus it can effectively reduce the load skew among the processors. Several experiments are done by changing the granule of copying itemsets, from the whole tree, to the small group of the frequent itemsets along the hierarchy. The coarser the grain, the easier the control but it is rather difficult to achieve the sufficient load balance. The finer the grain, the more complicated the control is required but it can balance the load quite well.

We implemented proposed algorithms on IBM SP-2. Performance evaluations show that our algorithms are effective for handling skew and attain sufficient speedup ratio.
Changing the rules
Authors: Cherniack Mitch , Zdonik Stan
Published: November 2005

Rule-based optimizers are extensible because they consist of modifiable sets of rules. For modification to be straightforward, rules must be easily reasoned about (i.e., understood and verified). At the same time, rules must be expressive and efficient (to fire) for rule-based optimizers to be practical. Production-style rules (as in [15]) are expressed with code and are hard to reason about. Pure rewrite rules (as in [1]) lack code, but cannot atomically express complex transformations (e.g., normalizations). Some systems allow rules to be grouped, but sacrifice efficiency by providing limited control over their firing. Therefore, none of these approaches succeeds in making rules expressive, efficient and understandable.

We propose a language (COKO) for expressing an alternative form of input to a rule-based optimizer. A COKO
transformation
consists of a set of declarative (KOLA) rewrite rules and a (firing) algorithm that specifies their firing. It is straightforward to reason about COKO transformations because all query modification is expressed with declarative rewrite rules. Firing is specified algorithmically with an expressive language that provides direct control over how query representations are traversed, and under what conditions rules are fired. Therefore, COKO achieves a delicate balance of understandability, efficiency and expressivity.
Interaction of query evaluation and buffer management for information retrieval
Authors: Jónsson Björn T. , Franklin Michael J. , Srivastava Divesh
Published: November 2005

The proliferation of the World Wide Web has brought information retrieval (IR) techniques to the forefront of search technology. To the average computer user, “searching” now means using IR-based systems for finding information on the WWW or in other document collections. IR query evaluation methods and workloads differ significantly from those found in database systems. In this paper, we focus on three such differences. First, due to the inherent fuzziness of the natural language used in IR queries and documents, an additional degree of flexibility is permitted in evaluating queries. Second, IR query evaluation algorithms tend to have access patterns that cause problems for traditional buffer replacement policies. Third, IR search is often an iterative process, in which a query is repeatedly refined and resubmitted by the user. Based on these differences, we develop two complementary techniques to improve the efficiency of IR queries: 1) Buffer-aware query evaluation, which alters the query evaluation process based on the current contents of buffers; and 2) Ranking-aware buffer replacement, which incorporates knowledge of the query processing strategy into replacement decisions. In a detailed performance study we show that using either of these techniques yields significant performance benefits and that in many cases, combining them produces even further improvements.
Cost-based query scrambling for initial delays
Authors: Urhan Tolga , Franklin Michael J. , Amsaleg Laurent
Published: November 2005

Remote data access from disparate sources across a wide-area network such as the Internet is problematic due to the unpredictable nature of the communications medium and the lack of knowledge about the load and potential delays at remote sites. Traditional, static, query processing approaches break down in this environment because they are unable to adapt in response to unexpected delays. Query scrambling has been proposed to address this problem. Scrambling modifies query execution plans on-the-fly when delays are encountered during runtime. In its original formulation, scrambling was based on simple heuristics, which although providing good performance in many cases, were also shown to be susceptible to problems resulting from bad scrambling decisions. In this paper we address these shortcomings by investigating ways to exploit query optimization technology to aid in making intelligent scrambling choices. We propose three different approaches to using query optimization for scrambling. These approaches vary, for example, in whether they optimize for total work or response-time, and whether they construct partial or complete alternative plans. Using a two-phase randomized query optimizer, a distributed query processing simulator, and a workload derived from queries of the TPCD benchmark, we evaluate these different approaches and compare their ability to cope with initial delays in accessing remote sources. The results show that cost-based scrambling can effectively hide initial delays, but that in the absence of good predictions of expected delay durations, there are fundamental tradeoffs between risk aversion and effectiveness.
Integration of heterogeneous databases without common domains using queries based on textual similarity
Authors: Cohen William W.
Published: November 2005

Most databases contain “name constants” like course numbers, personal names, and place names that correspond to entities in the real world. Previous work in integration of heterogeneous databases has assumed that local name constants can be mapped into an appropriate global domain by normalization. However, in many cases, this assumption does not hold; determining if two name constants should be considered identical can require detailed knowledge of the world, the purpose of the user's query, or both. In this paper, we reject the assumption that global domains can be easily constructed, and assume instead that the names are given in natural language text. We then propose a logic called WHIRL which reasons explicitly about the
similarity
of local names, as measured using the vector-space model commonly adopted in statistical information retrieval. We describe an efficient implementation of WHIRL and evaluate it experimentally on data extracted from the World Wide Web. We show that WHIRL is much faster than naive inference methods, even for short queries. We also show that inferences made by WHIRL are surprisingly accurate, equaling the accuracy of hand-coded normalization routines on one benchmark problem, and outperforming exact matching with a plausible global domain on a second.
An alternative storage organization for ROLAP aggregate views based on cubetrees
Authors: Kotidis Yannis , Roussopoulos Nick
Published: November 2005

The Relational On-Line Analytical Processing (ROLAP) is emerging as the dominant approach in data warehousing with decision support applications. In order to enhance query performance, the ROLAP approach relies on selecting and materializing in summary tables appropriate subsets of aggregate views which are then engaged in speeding up OLAP queries. However, a straight forward relational storage implementation of materialized ROLAP views is immensely wasteful on storage and incredibly inadequate on query performance and incremental update speed. In this paper we propose the use of
Cubetrees
, a collection of packed and compressed R-trees, as an alternative storage and index organization for ROLAP views and provide an efficient algorithm for mapping an arbitrary set of OLAP views to a collection of Cubetrees that achieve excellent performance. Compared to a conventional (relational) storage organization of materialized OLAP views, Cubetrees offer at least a 2-1 storage reduction, a 10-1 better OLAP query performance, and a 100-1 faster updates. We compare the two alternative approaches with data generated from the TPC-D benchmark and stored in the Informix Universal Server (IUS). The straight forward implementation materializes the ROLAP views using IUS tables and conventional B-tree indexing. The Cubetree implementation materializes the same ROLAP views using a
Cubetree Datablade
developed for IUS. The experiments demonstrate that the Cubetree storage organization is superior in storage, query performance and update speed.
Extracting schema from semistructured data
Authors: Nestorov Svetlozar , Abiteboul Serge , Motwani Rajeev
Published: November 2005

Semistructured data is characterized by the lack of any fixed and rigid schema, although typically the data has some implicit structure. While the lack of fixed schema makes extracting semistructured data fairly easy and an attractive goal, presenting and querying such data is greatly impaired. Thus, a critical problem is the discovery of the structure implicit in semistructured data and, subsequently, the recasting of the raw data in terms of this structure. In this paper, we consider a very general form of semistructured data based on labeled, directed graphs. We show that such data can be typed using the greatest fixpoint semantics of monadic datalog programs. We present an algorithm for approximate typing of semistructured data. We establish that the general problem of finding an optimal such typing is NP-hard, but present some heuristics and techniques based on clustering that allow efficient and near-optimal treatment of the problem. We also present some preliminary experimental results.
Integrating association rule mining with relational database systems
Authors: Sarawagi Sunita , Thomas Shiby , Agrawal Rakesh
Published: November 2005

Data mining on large data warehouses is becoming increasingly important. In support of this trend, we consider a spectrum of architectural alternatives for coupling mining with database systems. These alternatives include: loose-coupling through a SQL cursor interface; encapsulation of a mining algorithm in a stored procedure; caching the data to a file system on-the-fly and mining; tight-coupling using primarily user-defined functions; and SQL implementations for processing in the DBMS. We comprehensively study the option of expressing the mining algorithm in the form of SQL queries using Association rule mining as a case in point. We consider four options in SQL-92 and six options in SQL enhanced with object-relational extensions (SQL-OR). Our evaluation of the different architectural alternatives shows that from a performance perspective, the Cache-Mine option is superior, although the performance of the SQL-OR option is within a factor of two. Both the Cache-Mine and the SQL-OR approaches incur a higher storage penalty than the loose-coupling approach which performance-wise is a factor of 3 to 4 worse than Cache-Mine. The SQL-92 implementations were too slow to qualify as a competitive option. We also compare these alternatives on the basis of qualitative factors like automatic parallelization, development ease, portability and inter-operability.
AutoAdmin “what-if” index analysis utility
Authors: Chaudhuri Surajit , Narasayya Vivek
Published: November 2005

As databases get widely deployed, it becomes increasingly important to reduce the overhead of database administration. An important aspect of data administration that critically influences performance is the ability to select indexes for a database. In order to decide the right indexes for a database, it is crucial for the database administrator (DBA) to be able to perform a
quantitative analysis
of the existing indexes. Furthermore, the DBA should have the ability to propose hypothetical (“what-if”) indexes and quantitatively analyze their impact on performance of the system. Such impact analysis may consist of analyzing workloads over the database, estimating changes in the cost of a workload, and studying index usage while taking into account projected changes in the sizes of the database tables. In this paper we describe a novel index analysis utility that we have prototyped for Microsoft SQL Server 7.0. We describe the interfaces exposed by this utility that can be leveraged by a variety of front-end tools and sketch important aspects of the user interfaces enabled by the utility. We also discuss the implementation techniques for efficiently supporting “what-if” indexes. Our framework can be extended to incorporate analysis of other aspects of physical database design.
On parallel processing of aggregate and scalar functions in object-relational DBMS
Authors: Jaedicke Michael , Mitschang Bernhard
Published: November 2005

Nowadays parallel object-relational DBMS are envisioned as the next great wave, but there is still a lack of efficient implementation concepts for some parts of the proposed functionality. Thus one of the current goals for parallel object-relational DBMS is to move towards higher performance. In this paper we develop a framework that allows to process user-defined functions with data parallelism. We will describe the class of partitionable functions that can be processed parallelly. We will also propose an extension which allows to speed up the processing of another large class of functions by means of parallel sorting. Functions that can be processed by means of our techniques are often used in decision support queries on large data volumes, for example. Hence a parallel execution is indispensable.
Secure and portable database extensibility
Authors: Godfrey Michael , Mayr Tobias , Seshadri Praveen , von Eicken Thorsten
Published: November 2005

The functionality of extensible database servers can be augmented by user-defined functions (UDFs). However, the server's security and stability are concerns whenever new code is incorporated. Recently, there has been interest in the use of Java for database extensibility. This raises several questions: Does Java solve the security problems? How does it affect efficiency?

We explore the tradeoffs involved in extending the PREDATOR object-relational database server using Java. We also describe some interesting details of our implementation. The issues examined in our study are security, efficiency, and portability. Our performance experiments compare Java-based extensibility with traditional alternatives in the native language of the server. We explore a variety of UDFs that differ in the amount of computation involved and in the quantity of data accessed. We also qualitatively compare the security and portability of the different alternatives. Our conclusion is that Java-based UDFs are a viable approach in terms of performance. However, there may be challenging design issues in integrating Java UDFs with existing database systems.
Wavelet-based histograms for selectivity estimation
Authors: Matias Yossi , Vitter Jeffrey Scott , Wang Min
Published: November 2005

Query optimization is an integral part of relational database management systems. One important task in query optimization is selectivity estimation, that is, given a query
P
, we need to estimate the fraction of records in the database that satisfy
P
. Many commercial database systems maintain histograms to approximate the frequency distribution of values in the attributes of relations.

In this paper, we present a technique based upon a multiresolution wavelet decomposition for building histograms on the underlying data distributions, with applications to databases, statistics, and simulation. Histograms built on the cumulative data distributions give very good approximations with limited space usage. We give fast algorithms for constructing histograms and using them in an on-line fashion for selectivity estimation. Our histograms also provide quick approximate answers to OLAP queries when the exact answers are not required. Our method captures the joint distribution of multiple attributes effectively, even when the attributes are correlated. Experiments confirm that our histograms offer substantial improvements in accuracy over random sampling and other previous approaches.
Memory management during run generation in external sorting
Authors: Larson Per-Åke , Graefe Goetz
Published: November 2005

If replacement selection is used in an external mergesort to generate initial runs, individual records are deleted and inserted in the sort operation's workspace. Variable-length records introduce the need for possibly complex memory management and extra copying of records. As a result, few systems employ replacement selection, even though it produces longer runs than commonly used algorithms. We experimentally compared several algorithms and variants for managing this workspace. We found that the simple best fit algorithm achieves memory utilization of 90% or better and run lengths over 1.8 times workspace size, with no extra copying of records and very little other overhead, for widely varying record sizes and for a wide range of memory sizes. Thus, replacement selection is a viable algorithm for commercial database systems, even for variable-length records.

Efficient memory management also enables an external sort algorithm that degrades gracefully when its input is only slightly larger than or a small multiple of the available memory size. This is not the case with the usual implementations of external sorting, which incur I/O for the entire input even if it is as little as one record larger than memory. Thus, in some cases, our techniques may reduce I/O volume by a factor 10 compared to traditional database sort algorithms. Moreover, the gradual rather than abrupt growth in I/O volume for increasing input sizes significantly eases design and implementation of intra-query memory management policies.
Replication, consistency, and practicality
Authors: Anderson Todd , Breitbart Yuri , Korth Henry F. , Wool Avishai
Published: November 2005

Previous papers have postulated that traditional schemes for the management of replicated data are doomed to failure in practice due to a quartic (or worse) explosion in the probability of deadlocks. In this paper, we present results of a simulation study for three recently introduced protocols that guarantee global serializability and transaction atomicity without resorting to the two-phase commit protocol. The protocols analyzed in this paper include a global locking protocol [10], a “pessimistic” protocol based on a
replication graph
[5], and an “optimistic” protocol based on a replication graph [7]. The results of the study show a wide range of practical applicability for the
lazy
replica-update approach employed in these protocols. We show that under reasonable contention conditions and sufficiently high transaction rate, both replication-graph-based protocols outperform the global locking protocol. The distinctions among the protocols in terms of performance are significant. For example, an offered load where 70% - 80% of transactions under the global locking protocol were aborted, only 10% of transactions were aborted under the protocols based on the replication graph. The results of the study suggest that protocols based on a replication graph offer practical techniques for replica management. However, it also shows that performance deteriorates rapidly and dramatically when transaction throughput reaches a saturation point.
Are we working on the right problems? (panel)
Authors: Stonebraker Michael
Published: November 2005

There appears to be a discrepancy between the research topics being pursued by the database research community and the key problems facing information systems decisions makers such as Chief Information Officers (CIOs). Panelists will present their view of the key problems that would benefit from a research focus in the database research community and will discuss perceived discrepancies. Based on personal experience, the most commonly discussed information systems problems facing CIOs today include:
Electronic commerce: tutorial
Authors: Adam Nabil R. , Yesha Yelena
Published: November 2005

As we embark on the information age the use of electronic information is spreading through all sectors of society, both nationally and internationally. As a result, commercial organizations, educational institutions and government agencies are finding it essential to be linked by world wide networks, and commercial Internet usage is growing at an accelerating pace.
Java and relational databases (tutorial)
Authors: Clossman Gray , Shaw Phil , Hapner Mark , Klein Johannes , Pledereder Richard , Becker Brian
Published: November 2005

This Tutorial presents the latest developments in the area of Java and Relational Databases. The material is based on the SQLJ consortium effort whose goal is to leverage Java technology for SQL processing. The SQLJ effort is driven by major industry vendors such as Oracle, Sybase, Tandem, JavaSoft, IBM, Informix and others. The SQLJ specifications describe Embedded SQL in Java, Java Stored Procedures, Java UDFs and Java Data Types.
Managing large systems with DB2 UDB
Authors: Eaton Chris
Published: November 2005

In this talk, we will describe the usability challenges facing large distributed corporations. As well, we will discuss what IBM's DB2 Universal Database is doing to address these complex issues.
Ubiquitous, self-tuning, scalable servers
Authors: Spiro Peter
Published: November 2005

Hardware developments allow wonderful reliability and essentially limitless capabilities in storage, networks, memory, and processing power. Costs have dropped dramatically. PCs are becoming ubiquitous.

The features and scalability of DBMS software have advanced to the point where most commercial systems can solve virtually all OLTP and DSS requirements.

The Internet and application software packages allow rapid deployment and facilitate a broad range of solutions.
The PointCast network (abstract)
Authors: Ramakrishnan Satish , Dayal Vibha
Published: November 2005

PointCast Inc, the inventor and leader in broadcast news via the Internet and corporate intranets was founded in 1992 to deliver news as it happens from leading sources such as CNN, the New York Times, Wall Street Journal Interactive Edition and more, directly to a viewer's computer screen.

The PointCast Network is an integrated client/server system. The system give users control of selecting kinds of information the client retrieves and, within limits, the frequency of those retrievals.

The system is divided into client and server segments, referred to as “PointCast Client” and “the DataCenter” respectively. PointCast client is a program that runs on the user's Internet-connected computer, and performs a number of functions in addition to retrieving information from the DataCenter.

The server side of the system, known as the PointCast DataCenter, supports the client by providing compelling content in a timely fashion. The Data Center is composed of multiple sites geographically distributed all over US, each carrying a number of industrial strength web servers called “PointServers”. The PointServers are highly customized and “infinitely” scalable to serve close to 200 million requests handled by the PointCast network in a day.

The PointCast network receives content from over 100 different sources via satellite links or over the internet. A cluster of servers in the Data Center run customized processes round the clock which assimilate data from various sources to index, format and store it in multiple content databases.

This presentation will describe the basic plumbing of the PointCast Network and how some of the challenges of establishing one of the busiest data centers in the world were addressed and implemented. It will focus on following issues:

fault tolerance

load balancing

achieving scalability through pre-caching on servers

packaging information to optimize internet bandwidth usage

minimizing data latency.
Developing a high traffic, read-only Web site
Authors: Nauman John , Suorsa Ray
Published: November 2005

In this paper, we describe some of the considerations for designing highly trafficked web sites with read-only or read mostly characteristics.
Real business processing meets the Web
Authors: Chong James
Published: November 2005

Charles Schwab and Co, Inc. is a major web trader generating a large proportion of its revenue from the Web. That revenue is based on both having a site with lots of useful facilities and also the speed of execution, ability to cope with peaks in demand volumes, and the reliability of the site and its underlying services. James Chong, VP Architecture and Planning at Schwab, will talk about the fundamental infrastructure that supports the Web trading, and his plans for its evolution.
Olympic records for data at the 1998 Nagano games
Authors: Lassettre Edwin R.
Published: November 2005

The 1998 Nagano Olympic games had more intensive demands on data management than any previous Olympics in history. This talk will take you behind the scenes to talk about the technical challenges and the architectures that made it possible to handle 4.5 Terabytes of data and sustain a total of almost 650 million web requests, reaching a peak of over 103K per minute. We will discuss the overall structure of the most comprehensive and heavily used Internet technology application in history. Many products were involved, both hardware and software, but this talk will focus in on the database and web challenges, the technology that made it possible to support this tremendous workload. High availability, data integrity, high performance, support of both SMPs and clustered architectures were among the features and functions that were critical. We will cover the Olympic Results System, the Commentator Information System, Info '98, Games Management, and the Olympic web site that made this information available to the Internet community. The speaker will be Ed Lassettre, IBM Fellow, and a key member of IBM's Olympic team.
Delivering high availability for Inktomi search engines
Authors: Brewer Eric A.
Published: November 2005

Inktomi provides the back-end for several well-known search engines, including Wired's HotBot and Microsoft's MS Start page. The services are supported by a highly available cluster with more than 300 CPUs and several hundred disks.
Microsoft.com
Authors: Kennamer Sherri
Published: November 2005

Microsoft.com, is the world's largest corporate website both in terms of site visitors and pages served. Overall, it is the fourth-largest website in total visitors behind America Online, Yahoo and Netscape. We offer 250,000 pages of content, viewable in all major browser versions (yes, we aggressively support Netscape), supported by three server farms internationally and featuring content updated as often as every three hours, seven days a week.
CQ
Authors: Liu Ling , Pu Calton , Tang Wei , Buttler David , Biggs John , Zhou Tong , Benninghoff Paul , Han Wei , Yu Fenghua
Published: November 2005

The CQ project at OGI, funded by DARPA, aims at developing a scalable toolkit and techniques for update monitoring and event-driven information delivery on the net. The main feature of the CQ project is a “personalized update monitoring” toolkit based on
continual queries
[3]. Comparing with the pure pull (such as DBMSs, various web search engines) and pure push (such as Pointcast, Marimba, Broadcast disks) technology, the CQ project can be seen as a hybrid approach that combines the pull and push technology by supporting personalized update monitoring through a combined client-pull and server-push paradigm.
Providing database-like access to the Web using queries based on textual similarity
Authors: Cohen William W.
Published: November 2005

Most databases contain “name constants” like course numbers, personal names, and place names that correspond to entities in the real world. Previous work in integration of heterogeneous databases has assumed that local name constants can be mapped into an appropriate global domain by normalization. Here we assume instead that the names are given in natural language text. We then propose a logic for database integration called WHIRL which reasons explicitly about the
similarity
of local names, as measured using the vector-space model commonly adopted in statistical information retrieval. An implemented data integration system based on WHIRL has been used to successfully integrate information from several dozen Web sites in two domains.
CONTROL
Authors: Avnur Ron , Hellerstein Joseph M. , Lo Bruce , Olston Chris , Raman Bhaskaran , Raman Vijayshankar , Roth Tali , Wylie Kirk
Published: November 2005

The CONTROL project at U.C. Berkeley has developed technologies to provide online behavior for data-intensive applications. Using new query processing algorithms, these technologies continuously improve estimates and confidence statistics. In addition, they react to user feedback, thereby giving the user control over the behavior of long-running operations. This demonstration displays the modifications to a database system and the resulting impact on aggregation queries, data visualization, and GUI widgets. We then compare this interactive behavior to batch-processing alternatives.
The multidimensional database system RasDaMan
Authors: Baumann P. , Dehmel A. , Furtado P. , Ritsch R. , Widmann N.
Published: November 2005

RasDaMan is a universal — i.e., domain-independent — array DBMS for multidimensional arrays of arbitrary size and structure. A declarative, SQL-based array query language offers flexible retrieval and manipulation. Efficient server-based query evaluation is enabled by an intelligent optimizer and a streamlined storage architecture based on flexible array tiling and compression.

RasDaMan is being used in several international projects for the management of geo and healthcare data of various dimensionality.
SuperSQL
Authors: Toyama Motomichi
Published: November 2005

SuperSQL is an extension of SQL that allows query results presented in various media for publishing and presentations with simple but sophisticated formatting capabilities. SuperSQL query can generate various kinds of materials, for example, a LaTeX source file to publish query results in a nested table, HTML or Java source files to present the result on WWW browsers, and other media including MS-Excel worksheet, Tcl/Tk, O2C, etc. O2C is a data manipulation language of O2 and thus useful to migrate data in a relational database to an object oriented database.

SuperSQL is meant to provide a theoretical and practical foundation for 4GL-type applications such as report writers and DB/WWW coordinators.

In this demonstration, we show how TFE reorganize the query results into various media in a universal way, first by grouping tuples according to an arbitrary tree structured schema, and by translating them with the constructors available in the target media.
Enhanced nearest neighbour search on the R-tree
Authors: Cheung King Lum , Fu Ada Wai-Chee
Published: November 2005

Multimedia databases usually deal with huge amounts of data and it is necessary to have an indexing structure such that efficient retrieval of data can be provided. R-Tree with its variations, is a commonly cited indexing method. In this paper we propose an improved nearest neighbor search algorithm on the R-tree and its variants. The improvement lies in the removal of two hueristics that have been used in previous R*-tree work, which we prove cannot improve on the pruning power during a search.
Efficient concurrency control in multidimensional access methods
Authors: Chakrabarti Kaushik , Mehrotra Sharad
Published: November 2005

The importance of multidimensional index structures to numerous emerging database applications is well established. However, before these index structures can be supported as access methods (AMs) in a “commercial-strength” database management system (DBMS), efficient techniques to provide transactional access to data via the index structure must be developed. Concurrent accesses to data via index structures introduce the problem of protecting ranges specified in the retrieval from phantom insertions and deletions (the
phantom problem
). This paper presents a dynamic granular locking approach to phantom protection in Generalized Search Trees(GiSTs), an index structure supporting an extensible set of queries and data types. The granular locking technique offers a high degree of concurrency and has a low lock overhead. Our experiments show that the granular locking technique (1) scales well under various system loads and (2) similar to the B-tree case, provides a significantly more efficient implementation compared to predicate locking for multidimensional AMs as well. Since a wide variety of multidimensional index structures can be implemented using GiST, the developed algorithms provide a general solution to concurrency control in multidimensional AMs. To the best of our knowledge, this paper provides the first such solution based on granular locking.
Snakes and sandwiches
Authors: Jagadish H. V. , Lakshmanan Laks V. S. , Srivastava Divesh
Published: November 2005

Physical layout of data is a crucial determinant of performance in a data warehouse. The optimal clustering of data on disk, for minimizing expected I/O, depends on the query workload. In practice, we often have a reasonable sense of the likelihood of different classes of queries, e.g., 40% of the queries concern calls made from
some
specific telephone number in
some
month. In this paper, we address the problem of finding an optimal clustering of records of a fact table on disk, given an expected workload in the form of a probability distribution over query classes.

Attributes in a data warehouse fact table typically have hierarchies defined on them (by means of auxiliary dimension tables). The product of the dimensional hierarchy levels forms a lattice and leads to a natural notion of query classes. Optimal clustering in this context is a combinatorially explosive problem with a huge search space (doubly exponential in number of hierarchy levels). We identify an important subclass of clustering strategies called
lattice paths
, and present a dynamic programming algorithm for finding the optimal lattice path clustering, in time linear in the lattice size. We additionally propose a technique called
snaking
, which when applied to a lattice path, always reduces its cost. For a representative class of star schemas, we show that for every workload, there is a snaked lattice path which is globally optimal. Further, we prove that the clustering obtained by applying snaking to the optimal lattice path is never much worse than the globally optimal snaked lattice path clustering. We complement our analyses and validate the practical utility of our techniques with experiments using TPC-D benchmark data.