Technology is improving at an amazing pace and one reason for this advancement is because of unprecedented growth in the field of Information Technology and also in Digital Integrated Circuit technology over the past few decades. The size of a typical modern database is in the order of high ends of gigabytes and even terabytes. Researchers were successful in designing complex databases but there is still lot of activity on effectively making use of this stored information. There have been significant advancements in the field of "Logic optimization" and also in "Information storage and retrieval" but there has been very little transfer of these methods. The purpose of this study is to investigate the use of powerful Computer Aided Design (CAD) techniques for efficient information storage and retrieval. In the work presented in this thesis, it is shown that Decision Diagrams can be used for efficient data storage and information retrieval. An efficient technique is proposed for each of the two key areas of research in Database systems known as "Query Optimization" and "Datamining". Encouraging results are obtained indicating that using hardware techniques for information processing can be a new approach for solving these problems. An SQL query is represented using a hardware data structure known as an AND/OR graph and an SQL parser is interfaced with AND/OR package to achieve query optimization. Optimization using AND/OR graphs works only in the Boolean domain and to make the process of query optimization more complete it has to be investigated in Multivalued domain. The possibility of using MDD as a data structure to represent the query in the multi valued domain is discussed and a synthesis technique is developed to synthesize Multi Valued Logic Networks using MDD. Another useful data structure known as BDD can be used to store the large transaction files used in datamining applications very effectively.

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As informações imprecisas e vagas, comumente encontradas na modelagem de problemas do mundo real, muitas vezes não são manipuladas de forma adequada por meio das consultas convencionais aos bancos de dados. Alternativamente, a teoria de conjuntos fuzzy tem sido considerada uma ferramenta bem promissora para tratamento destas informações consideradas imprecisas e, em determinados casos, até mesmo ambíguas. Esse trabalho utiliza a linguagem SQL padrão para apresentar uma abordagem fuzzy de consultas a bancos de dados relacionais. Estudos de casos referentes à aplicabilidade do método desenvolvido são apresentados a fim de mostrar as suas potencialidades em relação aos métodos tradicionais de consultas. / Often, the imprecise and vague information, commonly found in the modeling of real world problems, are not dealt in an appropriate way through conventional queries used in databases. Alternatively, the fuzzy set theory has been considered a very promising tool to treat imprecise and ambiguous information. This work uses the standard SQL language and fuzzy set theory to develop a fuzzy query method for relational databases. Simulation examples are presented to illustrate its potentialities in relation to the traditional query methods.

雲端運算環境的興起，軟體即服務(Software as a Service, SaaS)的營運模式也開始受到軟體開發商的注意，其中一項關鍵技術是支援多租戶的軟體開發。在設計多租戶應用程式時有許多需要考量的因素，包含每個租戶各自的客製化設定、資料安全性等等。本論文著重於資料層級的客製化部份，如何讓各個租戶之間可以共用資料庫，但又能提供租戶適度地更改其資料表綱要(schema)以達到客製化的需求。 為了解決資料層級客製化所面臨的問題，一種常見的作法是可延伸性表格(Extension Table Layout)。但是，在關聯式資料庫中實作可延伸性表格，軟體開發人員為了配合可延伸性表格的資料存放方式，所使用的SQL語句會變得相當複雜且易錯。因此，本研究實作一個系統工具協助軟體開發人員將SQL語句，從一租戶一資料表寫法自動轉換成以可延伸性表格邏輯表達的SQL語句，透過執行轉換後的語句來對儲存在可延伸性表格的資料進行增刪修改。 軟體開發人員在本系統工具的協助下，加入租戶識別碼(TenanId)的開發概念後，即可實際建立一個多租戶應用程式。為了評估本系統工具的效用，我們以其建置了一個多校(租戶)選課系統，並進行多項效能實驗以探討影響本系統工具效能的因素。初步的結果顯示，本系統工具可以協助軟體開發人員，以較低的代價滿足資料層級客製化應用的需求。 / Software as a service (SaaS) is an emerging service model of cloud computing. One of the key technology in SaaS is supporting multi-tenant applications. There are many considerations in the design of multi-tenant applications, including customized configuration of tenants and data security. In this thesis, we focus on data-level customized configuration, and propose an approach for not only sharing database between tenants but also supporting tenants to modify their table schemas within limits. Extension Table Layout is one solution for solving the problems in data-level customized configuration for multi-tenant applications. However, SQL statemenst based on the Extension Table Layout are rather complicated and error-prone. Thus, we develop a tool to help software developers that will automatically rewrite the SQL statements from the common Private Table Layout into those from the Extension Table Layout at runtime. In other words, our tool enable software developers to write SQL statements in a multi-tenant application like in a single tenant application. Indeed, software developers could develop a multi-tenant application easily by using our tool and the multi-tenant enabler - TenantId. In order to assess the feasibility of our tool, we develop an online multi-tenant course election application. Besides, we disscus the effectiveness of the factors that affecting our tool and work on a number of experiments and performance tests. The preliminary results show that our SQL rewriting tool can help software developers at a lower cost to meet the needs of data-level customized applications to a degree.

In this thesis we present an automated system that allows users to execute XPATH queries against an XML data source. The system exploits the shared-inlining mapping from XML to Relational data. At the core of the system is an XPATH to SQL transformation algorithm that produces corresponding SQL queries for a subset of XPATH. This approach allows one to utilize standard relational databases to store XML data. Given a DTD, the system creates appropriate relational tables based on the shared-inlining method. The system is capable of transforming an XML data source that conforms to the DTD into relational data. The main component of the system is the XPATH interpreter that parses an XPATH expression for the XML data source and transforms it into an equivalent SQL query. The SQL query is then executed against the relational database and results are packaged into XML and returned as the answer to the XPATH query. The use of the relational database to store and query the XML data is transparent to the user as they interact only with the XPATH interpreter. This methodology provides a novel technique to provide an XML database system implementation. Index Words: XML SQL transformation, XPATH to SQL queries, XSU, Data mapping.

Environmental data hold important information regarding humanity’s past, present, and future, and are managed in various ways. The database structure most commonly used in contemporary applications is the relational database. Its usage in the scientific world for managing environmental data is not as popular as in businesses enterprises. Attention is caught by the diverse nature and rapidly growing volume of environmental data that has been increasing substantially in recent. Environmental data for the Chukchi Sea, with its embedded potential oil resources, have become important for characterizing the physical, chemical, and biological environment. Substantive data have been collected recently by researchers from the Chukchi Sea Offshore Monitoring in the Drilling Area: Chemical and Benthos (COMIDA CAB) project. A modified Observations Data Model was employed for storing, retrieving, visualizing and sharing data. Throughout the project-based study, the processes of environmental data heterogeneity reconciliation and relational database model modification and implementation were carried out. Data were transformed into shareable information, which improves data interoperability between different software applications (e.g. ArcGIS and SQL server). The results confirm the feasibility and extendibility of employing relational databases for environmental data management. / text

The data modeling phase is one of the main phases in automated system development methods. Usually data modeling is separated as independent process which success and robustness depends largely on the intuition and experience of the data analyst. This can become problematic when IS database is being designed for large scale IS. To solve this type of problems it’s proposed to accomplish data modeling phase not as a separate, poorly with the generic modeling process connected part but as one of the fundamental system development phases. Functional Requirements Specification Method is proposed for this matter. This methods main idea is to build database model according to user requirements for the functionality of the system being developed. The purpose of this work is to present a process intended for building a entity relationship diagram from the analysed functional requirements specification metamodel and generation of the SQL DDL script (relational schema) from that model. The presented model will be implemented as one of the CASE tool modules specified for the database modeling and SQL DDL script generation. Implemented tool will be verified and it’s correctness will be experimentally approved.

Šio darbo tikslas – sukurti informacine sistema (IS), kuri atvaizduotų B2B transakcijas realizuojant BTP protokolą. IS yra palyginti jauna žinių sritis, jai šiek tiek daugiau nei 50 metų, tačiau be šiuolaikinių IS sunku įsivaizduoti šiandieninę įmonę. Pastaruoju metu IS sparčiai plinta, jos poreikiai vis labiau didėja: vykdomas nuotolinis mokymas, organizuojamas nuotolinis darbas (teledarbas), sparčiai plečiasi elektroninė prekyba, daug dėmesio skiriama medicinai, naujas galimybes žada elektroninės bibliotekos. Šis atliktas darbas apima daugelį paminėtų sričių, nes realizuojami duomenų mainai tarp IS nepriklausomai nuo įmonės dalykinės srities. Daugelyje įmonių duomenys kaupiami duomenų bazėse ar duomenų centruose, todėl norint realizuoti duomen�� mainus tarp IS programuotojams reikia įdėti nemažai pastangų, kad galėtų realizuoti duomenų mainus tarp paskirstytų sistemų ar duomenų bazių, juolab, kad vienos verslo įmonės duomenų gali nepakakti siekiant įgyti konkurencinį pranašumą. Šiame darbe atliktas duomenų apsikeitimo supaprastinimas, kuris leidžia atlikti duomenų mainus vienus metu tarp neriboto skaičiaus verslo įmonių vienu metu realizuojant visiems žinomą OASIS konsorciumo sukurtą BTP protokolą. Duomenų mainai vykdomi užklausiant verslo dalyvius standartinėmis SQL užklausomis, tokiu būdu šių duomenų prašantiems asmenims galima pateikti duomenis nepriklausomai nuo naudojamos duomenų bazės. Siekiant įgyvendinti sistemos išplečiamumą, duomenys yra pateikiami standartiniu... [toliau žr. visą tekstą] / This work aim is to create information systems (IS), which can implement B2B transaction by using the Business Transaction Protocol (BTP). IS has only 50 years history, but without IS we can’t imagine modern business company. Now computers are usable in most leading edge areas and theirs needs and power always grows. We use its in distance learning, organizing distance work (work-net), expeditiously developing electronic business, appointing a lot off attention to modernize medicine, new possibilities for electronic libraries. This work can be used in all mentioned regions implementing data exchange among computers regardless their actions in business. Many companies store data in database or data centers, so if we want to realize exchange data among computer – our programmers have to avail a lot of energy and workforce to realize exchange from remote systems or databases, especially, if some services and data are in different databases. This work can realize data exchange simplification, which executes data exchange from unlimited numbers of business companies. It uses well-known BTP protocol from OASIS consortium to exchange data. All needed data we get from business participants using standard SQL queries. Thus people which are asking for data – in this work we can offer to get data from different databases platforms. To access system in different programming languages, data are implemented into standard SOAP1.1 protocol - where they will be transported in XML document... [to full text]

Darbe nagrinėjama plačiausiai praktikoje paplitusiems duomenų šaltiniams – reliacinėms duomenų bazėms ir XML dokumentams – skirtų užklausų kalbų - SQL, XQuery ir XPath - užklausų struktūra ir savybės. Remiantis analizės rezultatais, sudarytas bendrinis užklausų modelis, kurio paskirtis – padėti formuoti vartotojų užklausas nepriklausomai nuo to, kokiomis technologijomis realizuoti duomenų šaltiniai. Sukurto modelio praktinio taikomumo galimybėms pademonstruoti pateikta juo paremta paieškos sistemos kūrimo metodika. / The thesis presents the analysis of SQL, XQuery and XPath query languages that are intended for the most widely used data sources, namely relational databases and XML documents. Based on the results of the analysis, a generic query model has been developed. The model should serve to help compose user queries without the context of a specific data source implementation technology. The applicability of the model in practice is demonstrated by creating methods for search system development, based on this model.

Šiame darbe sprendžiamos grafinio vientisumo reikalavimų vaizdavimo loginiuose duomenų modeliuose bei jų kodo realizavimo problemos. Sprendžiant šiuos uždavinius, buvo analizuojami vientisumo reikalavimų tipai, UML plėtimo mechanizmai bei esamos vientisumo reikalavimų įgyvendinimo CASE įrankiuose galimybės.Vientisumo reikalavimus UML modeliuose galima užrašyti OCL kalba, tačiau OCL yra per sudėtinga daugeliui projektuotojų. Be to, SQL kodo generavimas iš OCL kol kas nėra efektyvus. Šio magistrinio darbo tikslas yra padidinti UML CASE įrankių duomenų bazių projektavimo galimybes, sukuriant vientisumo reikalavimų vaizdavimo ir kodo generavimo priemones. / Fulfillment of data integrity constraint requirements is one of main problems in information system development process. The constraints are implemented at physical system development level. Despite the fact that most of current UML CASE tools allow to specify constraints using OCL language, for the most of system analytics and architects use of OCL is too complicated. Currently SQL code generated from OCL constraint implementation is not effective. In this study we will present alternative approach for constraint requirement implementation using UML2 extension possibilities – profiles and stereotypes with tag values. Also we will present SQL code generation template language and code template based constraint requirement transformation to SQL code algorithm. It was used to extend UML Case tool MagicDraw.