waashk/acm huggingface dataset:
performance enhancement through replication in an object-oriented dbms  in this paper we describe how replicated data can be used to speedup query processing in an object-oriented database system. the general idea is to use replicated data to eliminate some of the functional joins that would otherwise be required for query processing. we refer to our technique for replicating data as field replication because it allows individual data fields to be selectively replicated. in the paper we describe how field replication can be specified at the data model level and we present storage-level mechanisms to efficiently support it. we also present an analytical cost model to give some feel for how beneficial field replication can be and the circumstances under which it breaks down. while field replication is a relatively simple notion, the analysis shows that it can provide significant performance gains in many situations.  eugene j. shekita michael j. carey
declarative updates of relational databases  this article presents a declarative language, called update calculus, of relational database updates. a formula in update calculus involves conditions for the current database, as well as assertions about a new database. logical connectives and quantifiers become constructors of complex updates, offering flexible specifications of database transformations. update calculus can express all nondeterministic database transformations that are polynomial time.  for set-at-a-time evaluation of updates, we present a corresponding update algebra. existing techniques of query processing can be incorporated into update evaluation. we show that updates in update calculus can be translated into expressions in update algebra and vice versa.  weidong chen
from browsing to interacting: dbms support for responsive websites  internet websites increasingly rely on database management systems. there are several reasons for this trend:    * as sites grow larger, managing the content becomes impossible without the use of a dbms to keep track of the nature, origin, authorship, and modification history of each article.    * as sites become more interactive, tracking and logging user activity and user contributions creates valuable new data, which again is best managed using a dbms. the emerging paradigm of _customer-centric e-business_ places a premium on engaging users, building a relationship with them across visits, and leveraging their expertise and feed-back. supporting this paradigm means that we not only have to track what users visit on a site, we also have to enable them to offer opinions and contribute to the content of the website in various ways; naturally, this requires us to use a dbms.    * in order to personalize a user's experience, a site must dynamically construct (or at least fine-tune) each page as it is delivered, taking into account information about the user's past activity and the nature of the content on the current page. in other words, personalization is made possible by utilizing the information (about content and user activity) that we already indicated is best managed using a dbms.  in summary, as websites go beyond a passive collection of pages to be browsed and seek to present users with a personalized, interactive experience, the role of database management systems becomes central.  in this talk, i will present an overview of these issues, including a discussion of related techniques such as _cookies_ and _web server logs_ for tracking user activity.  raghu ramakrishnan
a survey on usage of sql  relational database systems have been on market for more than a decade. sql has been accepted as the standard query language of relational systems. to further understand the usage of relational systems and relational query language sql, we conducted a survey recently that covers various aspects of the usage of sql in industrial organizations. in this paper, we present those results that may interest dbms researcher and developers, including the profiles of sql users, the application areas where sql is used, the usage of different features of sql and difficulties encountered by sql users.  hongjun lu hock chuan chan kwok kee wei
integrating dynamically-fetched external information into a dbms for semistructured data  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.  jason mchugh jennifer widom
database prototyping and implementation (abstract only)  1\\. in previous work (beuerman, proc. csc '85 and proc. csc '86), we have used lisp to express relational data base operations. this work is, perhaps, best viewed as prototyping.  a number of different systems of relational data base operations have been implemented in pascal. these pascal implementations are based on their lisp prototypes.  these various pascal systems all provide for such standard database operations as deletion, insertion, selection and updating. other operations such as set- theoretic and i/o are also available.  because of pascal's strong typing (cf. lisp) an early version required all attribute values to be integers. later versions allow a full range of possibilities.  to provide for a user-friendly interface, menu-driven variants have been developed. these are evolving in the direction of natural language processing.  this work was begun at albright college, reading, pa.  d. r. beuerman
working with audio: integrating personal tape recorders and desktop computers  audio data is rarely used on desktop computers today, although audio is otherwise widely used for communication tasks. this paper describes early work aimed at creating computer tools that support the ways users may want to work with audio data. user needs for the system were determined by intervieweing people already working with audio data, using existing devices such as portable tape recorders. a preliminary prototype system -- consisting of a personal tape recorder for recording and simultaneously marking audio and a macintosh application for browsing these recordings -- was built. informal field user tests of this prototype system have indicated areas for improvement and directions for future work.  leo degen richard mander gitta salomon
closest pair queries in spatial databases  this paper addresses the problem of finding the k closest pairs between two spatial data sets, where each set is stored in a structure belonging in the r-tree family. five different algorithms (four recursive and one iterative) are presented for solving this problem. the case of 1 closest pair is treated as a special case. an extensive study, based on experiments performed with synthetic as well as with real point data sets, is presented. a wide range of values for the basic parameters affecting the performance of the algorithms, especially the effect of overlap between the two data sets, is explored. moreover, an algorithmic as well as an experimental comparison with existing incremental algorithms addressing the same problem is presented. in most settings, the new algorithms proposed clearly outperform the existing ones.  antonio corral yannis manolopoulos yannis theodoridis michael vassilakopoulos
on the menbership problem for functional and multivalued dependencies in relational databases  the problem of whether a given dependency in a database relation can be derived from a given set of dependencies is investigated. we show that the problem can be decided in polynomial time when the given set consists of either multivalued dependencies only or of both functional and multivalued dependencies and the given dependency is also either a functional or a multivalued dependency. these results hold when the derivations are restricted not to use the complementation rule.  catriel beeri
mocha: a self-extensible database middleware system for distributed data sources  we present mocha, a new self-extensible database middleware system designed to interconnect distributed data sources. mocha is designed to scale to large environments and is based on the idea that some of the user- defined functionality in the system should be deployed by the middleware system itself. this is realized by shipping java code implementing either advanced data types or tailored query operators to remote data sources and have it executed remotely. optimized query plans push the evaluation of powerful _data-reducing_ operators to the data source sites while executing _data- inflating_ operators near the client's site. the volume reduction factor is a new and more explicit metric introduced in this paper to select the best site to execute query operators and is shown to be more accurate than the standard selectivity factor alone. mocha has been implemented in java and runs on top of informix and oracle. we present the architecture of mocha, the ideas behind it, and a performance study using scientific data and queries. the results of this study demonstrate that mocha provides a more flexible, scalable and efficient framework for distributed query processing compared to those in existing middleware solutions.  manuel rodríguez-martinez nick roussopoulos
the design of an interactive online help desk in the alexandria digital library in large software systems such as digital libraries, electronic commerce applications, and customer support systems, the user interface and system are often complex and difficult to navigate. it is necessary to provide users with interactive online support to help users learn how to effectively use these applications. such online help facilities can include providing tutorials and animated demonstrations, synchronized activities between users and system supporting staff for real time instruction and guidance, multimedia communication with support staff such as chat, voice, and shared whiteboards, and tools for quick identification of user problems. in this paper, we investigate how such interactive online help support can be developed and provided in the context of a working system, the alexandria digital library (adl) for geospatially-referenced data. we developed an online help system, alexhelp!. alexhelp! supports collaborative sessions between the user and the librarian (support staff) that include activities such as map browsing and region selection, recorded demonstration sessions for the user, primitive tools for analyzing user sessions, and channels for voice and text based communications. the design of alexhelp! is based on user activity logs, and the system is a light-weight software component that can be easily integrated into the adl user interface client. a prototype of alexhelp! is developed and integrated into the adl client; both the adl client and alexhelp! are written in java. robert prince jianwen su hong tang yonggang zhao
semi-determinism (extended abstract)  we investigate under which conditions a non-deterministic query is semi- deterministic, meaning that two different results of the query to a database are isomorphic. we also consider uniform semi-determinism, meaning that all intermediate results of the computation are isomorphic. semi-determinism is a concept bridging the new trends of non-determinism and object generation in database query languages. our results concern decidability, both at compile time and at run time; expressibility of the infamous counting queries; and completeness, which is related to the issue of copy elimination raised by abiteboul and kannelakis.  jan van den bussche dirk van gucht
groupweb (video program) (abstract only): a groupware web browser  groupweb is a prototype browser that allows group members to visually share and navigate world wide web page in real time. its groupware features include document and view slaving for synchronizing information sharing, telepointers for enacting gestures, and relaxed "what you see is what i see" views to handle display differences. a groupware text editor lets groups create and attach annotations to pages. an immediate application of groupweb is as a presentation tool for real time distance education and conferencing. the video illustrates groupweb and all its features.  saul greenberg mark roseman
relative knowledge in a distributed database  let db be a database and let u1, , um be a collection of users each having at his or her disposal a query sublanguage lu1 generated by some view predicate each of these users knows only as much as he can learn from the database using his or her query sublanguage. such a knowledge is called relative knowledge in the paper and its various properties including the model and proof theory are investigated. the applications of relative knowledge in the database security and integrity are also discussed.  t. imielinski
geominer: a system prototype for spatial data mining  spatial data mining is to mine high-level spatial information and knowledge from large spatial databases. a spatial data mining system prototype, geominer, has been designed and developed based on our years of experience in the research and development of relational data mining system, dbminer, and our research into spatial data mining. the data mining power of geominer includes mining three kinds of rules: characteristic rules, comparison rules, and association rules, in geo-spatial databases, with a planned extension to include mining classification rules and clustering rules. the sand (spatial and nonspatial data) architecture is applied in the modeling of spatial databases, whereas geominer includes the spatial data cube construction module, spatial on-line analytical processing (olap) module, and spatial data mining modules. a spatial data mining language, gmql (geo-mining query language), is designed and implemented as an extension to spatial sql [3], for spatial data mining. moreover, an interactive, user-friendly data mining interface is constructed and tools are implemented for visualization of discovered spatial knowledge.  jaiwei han krzysztof koperski nebojsa stefanovic
learning about hidden events in system interactions  understanding how to use a computer system often requires knowledge of hidden events: things which happen as a result of user actions but which produce no immediate perceptible effect. how do users learn about these events? will learners explain the mechanism in detail or only at the level at which they are able to use it? we extend lewis' expl model of causal analysis, incorporating ideas from miyake, draper, and dietterich, to give an account of learning about hidden events from examples. we present experimental evidence suggesting that violations of user expectations trigger a process in which hidden events are hypothesized and subsequently linked to user actions using schemata for general classes of situations which violate user expectations.  stephen casner clayton lewis
the information grid: a framework for information retrieval and retrieval- centered applications  the information grid (infogrid) is a framework for building information access applications that provides a user interface design and an interaction model. it focuses on retrieval of application objects as its top level mechanism for accessing user information, documents, or services. we have embodied the infogrid design in an object-oriented application framework that supports rapid construction of applications. this application framework has been used to build a number of applications, some that are classically characterized as information retrieval applications, others that are more typically viewed as personal work tools.  ramana rao stuart k. card herbert d. jellinek jock d. mackinlay george g. robertson
finding generalized projected clusters in high dimensional spaces  high dimensional data has always been a challenge for clustering algorithms because of the inherent sparsity of the points. recent research results indicate that in high dimensional data, even the concept of proximity or clustering may not be meaningful. we discuss very general techniques for projected clustering which are able to construct clusters in arbitrarily aligned subspaces of lower dimensionality. the subspaces are specific to the clusters themselves. this definition is substantially more general and realistic than currently available techniques which limit the method to only projections from the original set of attributes. the generalized projected clustering technique may also be viewed as a way of trying to redefine clustering for high dimensional applications by searching for hidden subspaces with clusters which are created by inter-attribute correlations. we provide a new concept of using extended cluster feature vectors in order to make the algorithm scalable for very large databases. the running time and space requirements of the algorithm are adjustable, and are likely ta tradeoff with better accuracy.  charu c. aggarwal philip s. yu
safe stratified datalog with integer order does not have syntax  stratified datalog with integer (gap)-order (or datalog ,<z ) is considered. a datalog ,<z -program is said to be safe if its bottom-up processing terminates on all valid inputs. we prove that safe datalog ,<z programs do not have effective syntax in the sense that there is no recursively enumerable set s of safe datalog ,<z programs such that every safe datalog ,<z program is equivalent to a program in s.  alexei p. stolboushkin michael a. taitslin
adaptive, fine-grained sharing in a client-server oodbms: a callback-based approach  for reasons of simplicity and communication efficiency, a number of existing object-oriented database management systems are based on page server architectures; data pages are their minimum unit of transfer and client caching. despite their efficiency, page servers are often criticized as being too retrictive when it comes to concurrency, as existing systems use pages as the minimum locking unit as well. in this paper we show how to support object- level locking in a page-server context. several approaches are described, including an adaptive granularity approach that uses page-level locking for most pages but switches to object-level locking when finer-grained sharing is demanded. each of the approaches is based on extending the idea of callback locking. we study the performance of these approaches, comparing them to both a pure page server and a pure object server. for the range of workload that we have examined, our results indicate that the adaptive page server provides very good performance, usually outperforming the pure page server and the other page-server variants as well. in addition, the adaptive page server is often preferable to the pure object server; our results provides insight into when each approach is likely to perform better.  markos zaharioudakis michael j. carey michael j. franklin
improving oltp data quality using data warehouse mechanisms  research and products for the integration of heterogeneous legacy source databases in data warehousing have addressed numerous data quality problems in or between the sources. such a solution is marketed by team4 for the decision support of mobile sales representatives, using advanced view maintenance and replication management techniques in an environment based on relational data warehouse technology and lotus notes-based client systems. however, considering total information supply chain management, the capture of poor operational data, to be cleaned later in the data warehouse, appears sub- optimal. based on the observation that decision support clients are often closely linked to operational data entry, we have addressed the problem of mapping the data warehouse data quality techniques back to data quality measures for improving oltp data. the solution requires a warehouse-to-oltp workflow which employs a combination of view maintenance and view update techniques.  matthias jarke christoph quix guido blees dirk lehmann gunter michalk stefan stierl
timely access to future funding announcements  the last issue of this column appeared six months ago, so in the interim many requests for proposals have been issued, with many of their due dates already past. we are happy to announce the availability of up-to-the-minute funding information on line, so that the record's publication schedule need not prevent readers' timely access to funding information. in addition, we briefly recap recent requests for proposals from nasa, nlm, the human brain project, the us army, the us navy, arpa, nsf, and intel; more detailed information on any of these (except intel) can be found in the on-line archives. we also report on news at nsf and nist.  marianne winslett iris sheauyin chu
issues in the design of database programming languages  this paper discusses two issues in the design of database constructs for programming languages. the first issue is whether records in a database correspond to records in a programming language or to a distinct type such as tuple. the second issue is what facilities are provided to define the interface between an application program and a database.  the discussion below is based on our research on the rigel database programming language [rowe 79, 80a]. rigel is a block- structured language with constructs for accessing relational databases, a module construct for data abstraction, and an exception-handling mechanism. the first implementation of the language has recently been completed and is being distributed.  lawrence a. rowe
the measurement of information systems effectiveness: evaluating a measuring instrument information system effectiveness is an important phenomenon for both researchers and practitioners. despite widespread interest, and the importance of the uses, there have been no efforts to validate _computerworld's_ premier 100 rankings of information system effectiveness. this paper uses structural equation modeling in an attempt to validate the measuring instrument used to derive the _computerworld_ rankings.alternative models for the measuring instrument are proposed. using a reflective model, the findings raise doubts as to the reliability of the rankings, and both content validity and construct validity are also suspect. the reliability and validity are problematic because multiple indicators of the same construct must be homogeneous for it to make sense to combine them into a composite index. a solution to this problem is to represent information system effectiveness as a multidimensional construct, that is part of a causal model. based on previous research in the area, suggestions are offered to improve the measuring instrument. judy e. scott
a comparison of alternative continuous display techniques with heterogeneous multi-zone disks  a number of recent technological trends have made data intensive applications such as continuous media (audio and video) servers a reality. these servers are expected to play an important role in applications such as video-on- demand, digital library, news-on-demand, distance learning, etc. continuous media applications are data intensive and might require storage subsystems that consist of hundreds of (multi-zone) disk drives. with the current technological trends, a homogeneous disk subsystem might evolve to consist of a heterogeneous collection of disk drives. given such a storage subsystem, the system must continue to support a hiccup-free display of audio and video clips. this study describes extensions of four continuous display techniques for multi-zone disk drives to a heterogeneous platform. these techniques include ibm's logical track [21], hp's track pairing [4], and usc's fixb [9] and deadline driven techniques [10]. we quantify the performance tradeoff associated with these techniques using analytical models and simulation studies. the obtained results demonstrate tradeoffs between the cost per simultaneous stream supported by a technique, the wasted disk space, and the incurred startup latency.  shahram ghandeharizadeh seon ho kim