waashk/acm huggingface dataset:
the temporal query language tquel  recently, attention has been focused on temporal databases, representing an enterprise over time. we have developed a new language, tquel, to query a temporal database. tquel was designed to be a minimal extension, both syntactically and semantically, of quel, the query language in the ingres relational database management system. this paper discusses the language informally, then provides a tuple relational calculus semantics for the tquel statements that differ from their quel counterparts, including the modification statements. the three additional temporal constructs defined in tquel are shown to be direct semantic analogues of quel's where clause and target list. we also discuss reducibility of the semantics to quel's semantics when applied to a static database. tquel is compared with ten other query languages supporting time.  richard snodgrass
cost-driven design for archival repositories  designing an archival repository is a complex task because there aremany alternative configurations, each with different reliability levels and costs. in this paper we study the costs involved in an archival repository and we introduce a design framework for evaluating alternatives and choosing the best configuration in terms of reliability and cost. we also present a new version of our simulation tool, archsim/c that aids in the decision process. the design framework and the usage of archsim/c are illustrated with a case study of a hypothetical (yet realistic) archival repository shared between two universities.  arturo crespo hector garcia-molina
data structures for efficient broker implementation  with the profusion of text databases on the internet, it is becoming increasingly hard to find the most useful databases for a given query. to attack this problem, several existing and proposed systems employ brokers to direct user queries, using a local database of summary information about the available databases. this summary information must effectively distinguish relevant databases and must be compact while allowing efficient access. we offer evidence that one broker, gloss, can be effective at locating databases of interest even in a system of hundreds of databased and can examine the performance of accessing thegloss summeries for two promising storage methods: the grid file and partitioned hashing. we show that both methods can be tuned to provide good performance for a particular workload (within a broad range of workloads), and we discuss the tradeoffs between the two data structures. as a side effect of our work, we show that grid files are more broadly applicable than previously thought; inparticular, we show that by varying the policies used to construct the grid file we can provide good performance for a wide range of workloads even when storing highly skewed data.  anthony tomasic luis gravano calvin lue peter schwarz laura haas
fast algorithms for projected clustering  the clustering problem is well known in the database literature for its numerous applications in problems such as customer segmentation, classification and trend analysis. unfortunately, all known algorithms tend to break down in high dimensional spaces because of the inherent sparsity of the points. in such high dimensional spaces not all dimensions may be relevant to a given cluster. one way of handling this is to pick the closely correlated dimensions and find clusters in the corresponding subspace. traditional feature selection algorithms attempt to achieve this. the weakness of this approach is that in typical high dimensional data mining applications different sets of points may cluster better for different subsets of dimensions. the number of dimensions in each such cluster-specific subspace may also vary. hence, it may be impossible to find a single small subset of dimensions for all the clusters. we therefore discuss a generalization of the clustering problem, referred to as the projected clustering problem, in which the subsets of dimensions selected are specific to the clusters themselves. we develop an algorithmic framework for solving the projected clustering problem, and test its performance on synthetic data.  charu c. aggarwal joel l. wolf philip s. yu cecilia procopiuc jong soo park
database programming in machiavelli - a polymorphic language with static type inference  machiavelli is a polymorphically typed programming language in the spirit of ml, but supports an extended method of type inferencing that makes its polymorphism more general and appropriate for database applications. in particular, a function that selects a field of a records is polymorphic in the sense that it can be applied to any record which contains a field with the appropriate type. when combined with a set data type and database operations including join and projection, this provides a natural medium for relational database programming. moreover, by implementing database objects as reference types and generating the appropriate views --- sets of structures with "identity" \--- we can achieve a degree of static type checking for object- oriented databases.  atsushi ohori peter buneman val breazu-tannen
how a personal document's intended use or purpose affects its classification in an office  this paper reports on one of the findings of a larger case study that attempts to describe how people organize documents in their own offices. in that study, several dimensions along which people make classificatory decisions were identified. of these, the use to which a document is put emerged as a strong determiner of that document's classification. the method of analysis is reviewed, and examples of different kinds of uses are presented, demonstrating that it is possible to describe a wide variety of specific instances using a closed set of descriptors. the suggestion is made that, in designing systems for organizing materials, it might be advantageous to incorporate information about contextual variables, such as use, since these seem to be particularly important in classification decisions made within personal environments.  b. kwasnik
constructing, organizing, and visualizing collections of topically related web resources  for many purposes, the web page is too small a unit of interaction and analysis. web sites are structured multimedia documents consisting of many pages, and users often are interested in obtaining and evaluating entire collections of topically related sites. once such a collection is obtained, users face the challenge of exploring, comprehending and organizing the items. we report four innovations that address these user needs: (1) we replaced the web page with the web site as the basic unit of interaction and analysis;(2) we defined a new informationstructure, the clan graph, that groups together sets of related sites; (3) we augment the representation of a site with a site profile, information about site structure and content that helps inform user evaluation of a site; and (4) we invented a new graph visualization, the auditorium visualization, that reveals important structural and content properties of sites within a clan graph. detailed analysis and user studies document the utility of this approach. the clan graph construction algorithm tends to filter out irrelevant sites and discover additional relevant items. the auditorium visualization, augmented with drill-down capabilities to explore site profile data, helps users to find high-quality sites as well as sites that serve a particular function.  loren terveen will hill brian amento
an improved third normal form for relational databases  in this paper, we show that some codd third normal form relations may contain "superfluous" attributes because the definitions of transitive dependency and prime attribute are inadequate when applied to sets of relations. to correct this, an improved third normal form is defined and an algorithm is given to construct a set of relations from a given set of functional dependencies in such a way that the superfluous attributes are guaranteed to be removed. this new normal form is compared with other existing definitions of third normal form, and the deletion normalization method proposed is shown to subsume the decomposition method of normalization.  tok-wang ling frank w. tompa tiko kameda
pad++: a zooming graphical interface for exploring alternate interface physics  we describe the current status of pad++, a zooming graphical interface that we are exploring as an alternative to traditional window and icon-based approaches to interface design. we discuss the motivation for pad++, describe the implementation, and present prototype applications. in addition, we introduce an informational physics strategy for interface design and briefly compare it with metaphor-based design strategies.  benjamin b. bederson james d. hollan
information gathering in the world-wide web: the w3ql query language and the w3qs system  the world wide web (www) is a fast growing global information resource. it contains an enormous amount of information and provides access to a variety of services. since there is no central control and very few standards of information organization or service offering, searching for information and services is a widely recognized problem. to some degree this problem is solved by "search services," also known as "indexers," such as lycos, altavista, yahoo, and others. these sites employ search engines known as "robots" or "knowbots" that scan the network periodically and form text-based indices. these services are limited in certain important aspects. first, the structural information, namely, the organization of the document into parts pointing to each other, is usually lost. second, one is limited by the kind of textual analysis provided by the "search service." third, search services are incapable of navigating "through" forms. finally, one cannot prescribe a complex database-like search. we view the www as a huge database. we have designed a high-level sql-like language called w3ql to support effective and flexible query processing, which addresses the structure and content of www nodes and their varied sorts of data. we have implemented a system called w3qs to execute w3ql queries. in w3qs, query results are declaratively specified and continuously maintained as views when desired. the current architecture of w3qs provides a server that enables users to pose queries as well as integrate their own data analysis tools. the system and its query language set a framework for the development of database-like tools over the www. a significant contribution of this article is in formalizing the www and query processing over it.  david konopnicki oded shmueli
structured online interactions: improving the decision-making of small discussion groups  a quantitative research experiment was used to examine whether a group's computer-mediated decision-making could be improved by providing a scripted structure to the groups text chat discussion. the study compared a regular chat discussion to a scripted chat discussion using lead line, a program that allows people to add a layer of pre-authored structure to regular text chat. we found that groups were more likely to come to consensus in structured chat discussions. in addition, groups applied the structure they learned to subsequent regular chat sessions.  shelly farnham harry r. chesley debbie e. mcghee reena kawal jennifer landau
preserving digital information forever  well within our lifetime we can expect to see most information being created, stored and used digitally. despite the growing importance of digital data, the wider community pays almost no attention to the problems of preserving this digital information for the future. even within the archival and library communities most work on digital preservation has been theoretical, not practical, and highlights the problems rather than giving solutions. physical libraries have to preserve information for long periods and this is no less true of their digital equivalents. this paper describes the preservation approach adopted in the victorian electronic record strategy (vers) which is currently being trialed within the victorian government, one of the states of australia. we review the various preservation approaches that have been suggested and describe in detail encapsulation, the approach which underlies the vers format. a key difference between the vers project and previous digital preservation projects is the focus within vers on the construction of actual systems to test and implement the proposed technology. vers is not a theoretical study in preservation.  andrew waugh ross wilkinson brendan hills jon dell'oro
human factors comparison of a procedural and a nonprocedural query language  two experiments testing the ability of subjects to write queries in two different query languages were run. the two languages, sql and tablet, differ primarily in their procedurality; both languages use the relational data model, and their halstead levels are similar. constructs in the languages which do not affect their procedurality are identical. the two languages were learned by the experimental subjects almost exclusively from manuals presenting the same examples and problems ordered identically for both languages. the results of the experiments show that subjects using the more procedural language wrote difficult queries better than subjects using the less procedural language. the results of the experiments are also used to compare corresponding constructs in the two languages and to recommend improvements for these constructs.  charles welty david w. stemple
design issues in distributed multidatabase systems  many reports have been published on the design strategies employed in the development of multidatabase systems. this paper examines some of these strategies and compares the design of the adds system to other efforts in the development of multidatabase systems. there are a number of interesting issues that arise when considering the design of a distributed multidatabase system. these include: (1) the levels of update control for the supported physical databases, (2) the cooperation of the global and local concurrency control schemes, (3) the treatment of concurrency control of a partially replicated distributed multidatabase directory, (4) reduced data transmission with enhanced semijoin algorithms and localized processing of intermediate query results, and (5) the network architecture required to support a distributed multidatabase system.  glenn r. thompson yuri j. breitbart
context interchange: new features and formalisms for the intelligent integration of information  the context interchange strategy presents a novel perspective for mediated data access in which semantic conflicts among heterogeneous systems are not identified a priori, but are detected and reconciled by a context mediator through comparison of contexts axioms corresponding to the systems engaged in data exchange. in this article, we show that queries formulated on shared views, export schema, and shared "ontologies" can be mediated in the same way using the context interchange framework. the proposed framework provides a logic-based object-oriented formalsim for representing and reasoning about data semantics in disparate systems, and has been validated in a prototype implementation providing mediated data access to both traditional and web- based information sources.  cheng hian goh stephane bressan stuart madnick michael siegel
documentation in the computer age: control and audit implications  over the past two decades, proportionally more and more of the corporation's information assets have been entered, processed, stored, and retrieved through edp facilities. today the new developments in data entry technology and the growing acceptance of distributive computing methodology are placing more edp power in the hands of the end-user. as business operations become more dependent upon supportive edp systems, the internal auditor has to focus more attention on the audit of the edp system itself.  the ability to independently evaluate a system can come only from knowledge of the system. it is for this reason that in an audit engagement involving computerized systems, the internal auditor should begin with a review of available system documentation.  j. jose cortez
comparison of access methods for time-evolving data  this paper compares different indexing techniques proposed for supporting efficient access to temporal data. the comparison is based on a collection of important performance criteria, including the space consumed, update processing, and query time for representative queries. the comparison is based on worst-case analysis, hence no assumptions on data distribution or query frequencies are made. when a number of methods have the same asymptotic worst- case behavior, features in the methods that affect average case behavior are discussed. additional criteria examined are the pagination of an index, the ability to cluster related data together, and the ability to efficiently separate old from current data (so that larger archival storage media such as write-once optical disks can be used). the purpose of the paper is to identify the difficult problems in accessing temporal data and describe how the different methods aim to solve them. a general lower bound for answering basic temporal queries is also introduced.  betty salzberg vassilis j. tsotras
handling very large databases with informix extended parallel server  in this paper, we investigate which problems exist in very large real databases and describe which mechanisms are provided by informix extended parallel server (xps) for dealing with these problems. currently the largest customer xps database contains 27 tb of data. a database server that has to handle such an amount of data has to provide mechanisms which allow achieving adequate performance and easing the usability. we will present mechanisms which address both of these issues and illustrate them with examples from real customer systems.  andreas weininger
towards context-based search engine selection  a well-known problem for web search is targeting search on information that satisfies users' information needs. user queries tend to be short, and hence often ambiguous, which can lead to inappropriate results from general-purpose search engines. this has led to a number of methods for narrowing queries by adding information. this paper presents an alternative approach that aims to improve query results by using knowledge of a user's current activities to select search engines relevant to their information needs, exploiting the proliferation of high-quality special-purpose search services. the paper introduces the prism source selection system and describes its approach. it then describes two initial experiments testing the system's methods.  david b. leake ryan scherle
qbi: an iconic query system for inexpert users  we present a general purpose query interface for inexpert users based on the manipulation of icons. the user perceives the reality of interest as structured in classes and attributes while the system internally maintains a schema rich of semantic information. the query language, fully visual, is based on the select and project paradigm that has been proven to be easy to understand. no path specification is required for composing a query. automatic feedbacks based on natural language generation and cardinality constraints analysis help the user in specifying his/her requests.  antonio massari stefano pavani lorenzo saladini
yet another note on minimal covers  in [atk88] atkins corrects a widely spread error in the algorithm for finding a minimal cover for a given set of functional dependencies. the erroneous form of the algorithm has been presented in [sa186,stw83,ul182,yan88]. unfortunately, though, there is an error also in the corrected algorithm.  atkins proposed the following algorithm for determining a minimal cover for a given set of functional dependencies f.  jyrki nummenmaa peter thanisch
translucent patches - dissolving windows  this paper presents motivation, design, and algorithms for using and implementing translucent, non-rectangular patches as a substitute for rectangular opaque windows. the underlying metaphor is closer to a mix between the architects yellow paper and the usage of white boards, than to rectangular opaque paper in piles and folders on a desktop.  translucent patches lead to a unified view of windows, sub-windows and selections, and provide a base from which the tight connection between windows, their content, and applications can be dissolved. it forms one aspect of on-going work to support design activities that involve "marking" media, like paper and white boards, with computers. the central idea of that research is to allow the user to associate structure and meaning dynamically and smoothly to marks on a display surface.  axel kramer
introduction to a system for distributed databases (sdd-1)  the declining cost of computer hardware and the increasing data processing needs of geographically dispersed organizations have led to substantial interest in distributed data management. sdd-1 is a distributed database management system currently being developed by computer corporation of america. users interact with sdd-1 precisely as if it were a nondistributed database system because sdd-1 handles all issues arising from the distribution of data. these issues include distributed concurrency control, distributed query processing, resiliency to component failure, and distributed directory management. this paper presents an overview of the sdd-1 design and its solutions to the above problems.  this paper is the first of a series of companion papers on sdd-1 (bernstein and shipman [2], bernstein et al. [4], and hammer and shipman [14]).  j. b. rothnie p. a. bernstein s. fox n. goodman m. hammer t. a. landers c. reeve d. w. shipman e. wong
query processing in a system for distributed databases (sdd-1)  this paper describes the techniques used to optimize relational queries in the sdd-1 distributed database system. queries are submitted to sdd-1 in a high- level procedural language called datalanguage. optimization begins by translating each datalanguage query into a relational calculus form called an envelope, which is essentially an aggregate-free quel query. this paper is primarily concerned with the optimization of envelopes.  envelopes are processed in two phases. the first phase executes relational operations at various sites of the distributed database in order to delimit a subset of the database that contains all data relevant to the envelope. this subset is called a reduction of the database. the second phase transmits the reduction to one designated site, and the query is executed locally at that site.  the critical optimization problem is to perform the reduction phase efficiently. success depends on designing a good repertoire of operators to use during this phase, and an effective algorithm for deciding which of these operators to use in processing a given envelope against a given database. the principal reduction operator that we employ is called a semijoin. in this paper we define the semijoin operator, explain why semijoin is an effective reduction operator, and present an algorithm that constructs a cost-effective program of semijoins, given an envelope and a database.  philip a. bernstein nathan goodman eugene wong christopher l. reeve james b. rothnie