Classical Database Research Articles

MULTI-SCALE ANALYSIS OF THE WEB OF DATA: A CHALLENGE TO THE COMPLEX SYSTEM'S COMMUNITY

The Web of Data (WoD) is an Internet-based network of data resources and their relations. It has recently taken flight and combines over a hundred interlinked data sources with more than 15 billion edges. A consequence of this recent success is that a paradigm shift has taken place: up to now the Web of Data could be studied, searched and maintained like a classical database; nowadays it has turned into a Complex System and needs to be studied as such. In this paper, we introduce the Web of Data as a challenging object of study and provide initial results on two network scales: the pure data-layer, and the global connection between groups data items. In this analysis, we show that the "official" abstract representation of the WoD does not fit the real distribution we derive from the lower scale. As interesting as these results are, bigger challenges for analysis await in the form of the highly dynamic character of the WoD, and the typed, and implicit, character of the edges which is, to the best of our knowledge, hitherto unstudied.

If You Have Too Much Data, then "Good Enough" Is Good Enough

Classic database systems offer crisp answers for a relatively small amount of data. These systems hold their data in one or a relatively small number of computers. With a tightly defined schema and transactional consistency, the results returned from queries are crisp and accurate. New systems have humongous amounts of data content, change rates, and querying rates and take lots of computers to hold and process. The data quality and meaning are fuzzy. The schema, if present, is likely to vary across the data. The origin of the data may be suspect, and its staleness may vary.

Three-Dimensional Surface Modeling using Intelligent Database Techniques

Range image acquisition can be defined as the process of determining the physical distance from a given observation point to all points of consideration in a three-dimensional (3D) surface object. The technology of range finders has been used for many years in military and airborne remote sensing survey applications. This paper suggests the use of computer databases (instead of mathematical formulas) for modeling 3D surfaces. The basic concept is the proper selection of representative samples from the measured range values to be records in the model database. The main contribution in this paper is developing an Intelligent Database Management System (IDMS) used for selecting samples and giving depth prediction at a given space point. The IDMS performs standard database operations such as adding, updating and deleting records in order to minimize the data storage memory size and prediction error. Search for specific data which are not previously stored in the database is impossible in classical database management systems (DMS).

BISC

The performance of a depth-first frequent itemset (FI) miming algorithm is closely related to the total number of recursions. In previous approaches this is mainly decided by the total number of FIs, which results in poor performance when a large number of FIs are involved. To solve this problem, a three-strategy adaptive algorithm, bitmap itemset support counting (BISC), is presented. The core strategy, BISC1, is used in the innermost steps of the recursion. For a database D with only s frequent items, a depth-first approach need up to s levels of recursions to detect all the FIs (up to 2 s ). BISC1 completely replaces these recursions with a special summation that directly calculates the supports of all the possible 2 s candidate itemsets. With BISC1 the run-time is entirely independent of the database after one database scan, and the per-candidate cost is only s . To offset the exponential growth of cost (both time and space) with BISC1 as s increases, a second strategy, BISC2, is introduced to effectively double the acceptable range of s . BISC2 divides an itemset into prefix and suffix and improves the performance by pruning all the itemsets with infrequent prefixes. If the total number of frequent items in D is high, the classic database projection strategy is used. In this case for the first s items a single run of BISC (1 or 2) is applied. For each of the remaining items, a projected database is created and the mining process proceeds recursively. To achieve optimal performance, BISC adaptively decides which strategy to use based on the dataset and minimum support. Experiments show that BISC outperforms previous approaches in all the datasets tested. Even though this does not guarantee that BISC will always perform the best, the result is impressive given the fact that most existing algorithms are only efficient in some types of datasets. The memory usage of BISC is also comparable to those of other algorithms.

Advanced processing for ontological queries

Ontology-based data access is a powerful form of extending database technology, where a classical extensional database (EDB) is enhanced by an ontology that generates new intensional knowledge which may contribute to answer a query. The ontological integrity constraints for generating this intensional knowledge can be specified in description logics such as DL-Lite. It was recently shown that these formalisms allow for very efficient query-answering. They are, however, too weak to express simple and useful integrity constraints that involve joins. In this paper we introduce a more expressive formalism that takes joins into account, while still enjoying the same low query-answering complexity. In our framework, ontological constraints are expressed by sets of rules that are so-called tuple-generating dependencies (TGDs) . We propose the language of sticky sets of TGDs, which are sets of TGDs with a restriction on multiple occurrences of variables (including joins) in the rule bodies. We establish complexity results for answering conjunctive queries under sticky sets of TGDs, showing, in particular, that ontological conjunctive queries can be compiled into first-order and thus SQL queries over the given EDB instance. We also show how sticky sets of TGDs can be combined with functional dependencies. In summary, we obtain a highly expressive and effective ontological modeling language that unifies and generalizes both classical database constraints and important features of the most widespread tractable description logics.

Quantum Private Queries: Security Analysis

A security analysis of the recently introduced Quantum Private Query (QPQ) protocol is presented. The latter is a cheat sensitive quantum protocol to perform a private search on a classical database. It allows a user to retrieve an item from the database without revealing which item was retrieved, and at the same time it ensures data privacy of the database (the information that the user retrieves in a query is bounded). The security analysis is based on information-disturbance tradeoffs which show that whenever the provider tries to obtain information on the query, the query (encoded into a quantum system) is disturbed so that the person querying the database can detect the privacy violation. The security bounds are derived under the assumption that a unique answer corresponds to each query. To remove this assumption, some simple variants of the protocol are illustrated, and it is conjectured that analogous security bounds apply to them.

Quantum Private Queries

We propose a cheat sensitive quantum protocol to perform a private search on a classical database which is efficient in terms of communication complexity. It allows a user to retrieve an item from the database provider without revealing which item he or she retrieved: if the provider tries to obtain information on the query, the person querying the database can find it out. The protocol ensures also perfect data privacy of the database: the information that the user can retrieve in a single query is bounded and does not depend on the size of the database. With respect to the known (quantum and classical) strategies for private information retrieval, our protocol displays an exponential reduction in communication complexity and in running-time computational complexity.

Benchmarking temporal database models with interval-based and temporal element-based timestamping

Starting from mid 1980s, there has been a debate about what data model is most appropriate for temporal databases. A fundamental choice one has to make is whether to use intervals of time or temporal elements to timestamp objects and events with the periods of validity. The advantage of using interval timestamps is that Start and End columns can be added to relations for treating them within the framework of classical databases, leading to quick implementation. Temporal elements are finite unions of intervals. The advantage of temporal elements is that timestamps become implicitly associated with values, tuples, and relations. Furthermore, since temporal elements, by design, are closed under set theoretical operations such as union, intersection and complementation, they lead to query languages that are natural. Here, we investigate the ease of use as well as system performance for the two approaches to help settle the debate.

Web Ontology Languages and Semantic Web Services

The current World Wide Web is syntactic and the content itself is only readable by humans. The next generation of the Web will combine existing Web technologies with knowledge representation formalisms. The Semantic Web proposes the mark-up of content on the Web using formal ontology's that structure essential data for the purpose of comprehensive machine understanding. On the syntactical level, standardization is an important topic. Many standards which can be used to integrate different information sources have evolved. Beside the classical database interfaces like ODBC, web-oriented standards like HTML, XML, RDF and OWL increase in importance. As the World Wide Web offers the greatest potential for sharing information, we will base our paper on these evolving standards.

Strategies for the effective identification of remotely related sequences in multiple PSSM search approach

Searches using position specific scoring matrices (PSSMs) have been commonly used in remote homology detection procedures such as PSI-BLAST and RPS-BLAST. A PSSM is generated typically using one of the sequences of a family as the reference sequence. In the case of PSI-BLAST searches the reference sequence is same as the query. Recently we have shown that searches against the database of multiple family-profiles, with each one of the members of the family used as a reference sequence, are more effective than searches against the classical database of single family-profiles. Despite relatively a better overall performance when compared with common sequence-profile matching procedures, searches against the multiple family-profiles database result in a few false positives and false negatives. Here we show that profile length and divergence of sequences used in the construction of a PSSM have major influence on the performance of multiple profile based search approach. We also identify that a simple parameter defined by the number of PSSMs corresponding to a family that is hit, for a query, divided by the total number of PSSMs in the family can distinguish effectively the true positives from the false positives in the multiple profiles search approach.

Flexible querying of semistructured data: A fuzzy-set-based approach

This article provides a general discussion about how flexible querying can be applied to semistructured data (SSD). We adapt flexible querying ideas, already used for classically structured databases, to XQuery-like querying of SSD for managing users' priority and preferences, but also for tackling with the variability of SSD underlying structures. Indeed flexible querying seems to be still more useful for SSD than for classical databases, because of the potential structural heterogeneity of the former. Fuzzy sets are useful for expressing flexible requirements on attribute values and for estimating the degree of similarity of tags, or attribute labels, with elements present in the request. Priorities are introduced in the request for specifying the relative importance of elementary requirements in terms of their semantic contents, but also preferences about the location of information in the structure. The evaluation of the queries uses a qualitative scale with a finite number of levels, and retrieved pieces of SSD are rank-ordered using a lexicographic vector procedure. Illustrative examples are provided. © 2007 Wiley Periodicals, Inc. Int J Int Syst 22: 723–737, 2007.

A Comparative Study for Crisp and Fuzzy Query by a Software Tool

In this paper, through a developed software, crisp and fuzzy query were compared on a classical database. By means of this fuzzy query software tool, some fields (attribute) of a database table can be fuzzified and a supplementary database, which includes fuzzy values, is formed. Developed software tool is applied on a sample database including some fields about the students for the evaluation of scholarship application. It is concluded that, the fuzzy query method is more flexible and the results of such query are more predictive and satisfactory.

A Conversation with Pat Selinger

Take Pat Selinger of IBM and James Hamilton of Microsoft and put them in a conversation together, and you may hear everything you wanted to know about database technology and weren’t afraid to ask. Selinger, IBM Fellow and vice president of area strategy, information, and interaction for IBM Research, drives the strategy for IBM’s research work spanning the range from classic database systems through text, speech, and multimodal interactions. Since graduating from Harvard with a Ph.D. in applied mathematics, she has spent almost 30 years at IBM, hopscotching between research and development of IBM’s database products.

Life science research and data management—what can they give each other?

"Databases for the life sciences" is not really a newly emerging area in databases. The Nucleotide Sequence Database from the European Molecular Biology Laboratory (EMBL) has been operational at the European Bioinformatics Institute (EBI) since 1980. SWISS-PROT, the classical database containing protein information, was established in 1986. Today, there are over a thousand different life science databases with contents ranging from gene-property data for different organisms to brain image data for patients with neurological disorders.

Defining “Pharmacy Technician”

Background: Legal definitions of “pharmacy technician” vary by state. Also, many pharmacy organizations have definitions of “pharmacy technician.” There is no consensus on the definition. Objective: To explore the legal definitions of a pharmacy technician and use of the term “professional judgment” in those definitions and develop an empirically and theoretically based definition of a pharmacy technician. Methods: Definitions of a pharmacy technician from the state statutes and regulations were found using LexisNexis State Capital and entered into an N-4 Classic database. The database was then coded through an iterative process of content analysis. A definition was developed using the content analysis and literature-based theory. Results: Definitions were found for 42 states (84%). Five main concepts were found to exist in the definitions: credentialing, designation, functions, practice site, and supervision. An empiric and theoretically based definition of a pharmacy technician was developed. Conclusions: Statutory and regulatory definitions of a pharmacy technician tend to define technicians in terms that preserve the dispensing role for pharmacists. Definitions of a pharmacy technician should focus on the types of services pharmacy technicians provide and the types of credentials they must have, rather than what they may not do and who they are not. The use of the term “professional judgment” in defining a pharmacy technician lacks precision and is therefore not helpful in defining “pharmacy technician.”

Global intelligence benevolent builder (GIBB): a system automating integration of heterogeneous classical databases and web

In this paper we investigate highly sophisticated mechanisms that merge and automate interoperability of heterogeneity classical database systems together with the World Wide Web as one world. In particular, we introduce the global intelligence benevolent builder (GIBB) system that employs Intelligent Benevolent Architecture (IBA), which is comprised of assertions, integration rules, conceptual model constructs and agents. IBAs boost the components' versatility to reconcile the semantics involved in data sharing in order to withstand the dynamic computer technology in the present and future information age. Due to the IBAs power of intelligence, and in order to save costs and time, GIBB also has the capability to filter out and process only the relevant operational sources like preferences (i.e. customer's interest) from the sites.

Mobile user recovery in the context of internet transactions

With the expansion of Web sites to include business functions, a user interfaces with e-businesses through an interactive and multistep process, which is often time-consuming. For mobile users accessing the Web over digital cellular networks, the failure of the wireless link, a frequent occurrence, can result in the loss of accomplished prior to the disruption. This must then be repeated upon subsequent reconnection - often at significant cost in time and computation. This disconnection-reconnection-repeat work cycle may cause mobile clients to incur substantial monetary as well as resource (such as battery power) costs. In this paper, we propose a protocol for a user to an appropriate recent interaction state after such a failure. The objective is to minimize the amount of that needs to be redone upon restart after failure. Whereas classical database focuses on recovering the system, i.e., all transactions, our considers the problem of recovering a particular user interaction with the system. This problem encompasses several interesting subproblems: (1) modeling user interaction in a way that is useful for recovery, (2) characterizing a user's recovery state, (3) determining the state to which a user should be recovered, and (4) defining a mechanism. We describe the user interaction with one or more Web sites using intuitive and familiar concepts from database transactions. We call this interaction an Internet transaction (iTX), distinguish this notion from extant transaction models, and develop a model for it, as well as for a user's state on a Web site. Based on the twin foundations of our iTX and state models, we finally describe an effective protocol for recovering users to valid states in Internet interactions.

Level-2 fuzzy sets and their usefulness in object-oriented database modelling

In the real world information is, for the most part, available in an imperfect form. Managing this kind of information with classical database systems brings a disadvantageous loss of data semantics along. Therefore, advanced database modelling techniques are necessary. This paper deals with a uniform and advantageous representation of both perfect and imperfect ‘real world’ information in object-oriented databases. An object-oriented data(base) modelling technique, based on the concept ‘level-2 fuzzy set’, is presented. Hereby, the focus is on the semantic definitions of the structural, as well as on the behavioural aspects of the data. It is shown how level-2 fuzzy sets can be used to generalise the concept ‘type’. Since types are generally recognised to be the basic building blocks of object-oriented database models, generalised types can be used as basic notions of fuzzy object-oriented database models. Finally, it is illustrated and discussed how the ODMG data model can be generalised to handle ‘real world’ data in a more advantageous way.

古典籍の XML 化プロセスにおける諸問題 －日本古典文学本文データベース再構築作業を通して－

古典籍の XML 化プロセスにおける諸問題 －日本古典文学本文データベース再構築作業を通して－

El proceso de creación de una base de datos web

The need for making information available on the Web, so that it can be accessed from anywhere, has resulted in many new web-based database sites. In many cases the data are unorganised with frequent duplication of information. This informal organisation and information redundancy make site maintenance a much more difficult task, giving rise to inconsistencies, data that is difficult to access, etc. The database community knows that one way of avoiding these problems is to make use of the facilities provided by technology. But the development process of databases on the web is different than that of traditional databases. Therefore it is necessary to adapt the classical database development methodologies (process as well as techniques, notations and models) for working with web databases. This paper outlines the main methodologies for creating web databases and sums up the Midas/db methodology, developed by the Kybele Research Group of the University Rey Juan Carlos, in Madrid.