This work is focused at new Microsoft technology for querying data LINQ (Language intergrated query). It is built as complex technology, it allows working with various data sources. For example it contains collections of objects, created for temporary storing data in memory, but also data in robust database systems. In first part of this work I describe how data was queried before LINQ was on scene and what reasons made LINQ originate. Then I analyze new features in C# that were prerequisites for creating language integrated query as part of base libraries. Next part focuses at query operators, their interfaces and provides examples of use. Then I describe LINQ technology in complex, I create and describe in detail process of execution of LINQ query. Next chapter describes querying ADO.NET Datasets. Practical examples are created for both typed and untyped Datasets. In following chapter I analyze LINQ to SQL functionality. There is described method of implementation, mainly translation LINQ query to SQL language, integrated object rational mapping tool, change tracking in mapped objects including concurrency problems. At the end of the chapter I sketch the future in data access in ADO.NET entities. In last but one chapter is created complex application of use LINQ technology. Application is built as thin client that uses LINQ as for reading and manipulating data from relational database. In the application is LINQ also used common work with component that presents data. At the end part of this work is LINQ technology summarized. Contribution and pitfalls of LINQ technology are also described.

Detta examensarbete behandlar utvecklingen av en prototyp ämnad att underlätta hantering av ett företags artiklar vid lanseringen av en e-handel. Prototypens uppgift är att fylla luckan mellan affärssystem och e-handelsplattform (CMS). I prototypen kan användare, med utgång från artikelinformation extraherad från ett företags affärssystem, redigera artiklar, skapa produkter av artiklar och skapa kategorier för produkter. Idén bakom prototypen kommer från att många e-handelsplattformar visar brister vad det gäller artikelhantering. Arbetet utförs på uppdrag, och med stöd, av ett företag som arbetar med att utveckla e-handelslösningar. Prototypen tog formen av en webbapplikation utvecklad med hjälp av ASP.NET och programspråket C#. Designskisser på gränssnittet skapades i programmet Balsamiq Mockups. Utifrån designskisserna byggdes gränssnittet upp, i Microsoft Visual Studio, med kontroller utvecklade av företaget DevExpress; de erbjuder en serie ASP.NET kontroller med Ajax-funktionalitet. För att lagra resultatet av de åtgärder som utförs i gränssnittet (redigering av artiklar, produkter och kategorier) skapades en relationsdatabas. Som teknik för databaskommunikation användes LINQ to SQL. Under arbetets gång besvarades frågeställningarna ”finns det liknande system som fyller samma funktion som prototypen?” och ”vilka av DevExpress kontroller lämpas sig bäst för att bygga upp gränssnittet?”. Svaret på den första frågan är ja, men inga system vilka helt kan ersätta prototypen. Svaret på den andra frågan användes som underlag vid utveckling av prototypen. Resultatet av utvecklingsarbetet blev en fungerande prototyp som uppfyller tidigare nämnda syfte. Arbetet har lett till att studenten lärt sig nya tekniker och kunnat breddasina kunskaper inom .NET-ramverket

Idag är det vanligt på större IT-företag att konstellationen i de agila teamen ändras i och med projektens kompetensbehov. Förutom de egna anställda, hyrs ofta konsulter in med spetskompetens inom olika områden. För att effektivisera projektplanering, kompetensutveckling och för att hitta kompetenser i andra team på företaget, behövdes ett verktyg för att hantera kompetenserna på företaget. Denna rapport bygger på ett uppdrag förmedlat av Transportstyrelsen. Transportstyrelsens IT-enhet växer och ett stort antal konsulter är ständigt på plats. Uppdraget gick ut på att ta fram en prototyp till en webbaserad plattform för att hantera de olika teamens kompetenser. Projektet resulterade i en webbapplikation med ett användargränssnitt byggt i Angular med data lagrad i en code first-baserad SQL-server. Kommunikationen mellan Angular och SQL-servern görs över ett Web-Api. / Today, it is common for large IT companies that the constellation of the agile teams changes based on the projects skills requirements. In addition to their own employees, consultants are often hired with excellence in different areas. In order to streamline project planning, skills development and finding skills in other teams in the company, a tool was required to manage the skills in the company.   This report is based on a mission conveyed by the Swedish transport Agency. The Transport Agency's IT unit is growing and a large number of consultants are constantly present. The mission was to produce a prototype of a web-based platform to handle teams various skills.   The project resulted in a web application with a user interface built in Angular with data stored in a code first-based SQL server. Communication between Angular and the SQL Server is done over a Web Api.

This thesis demonstrates the use of XML (eXtensible Markup Language) instance documents based on XBRL taxonomy (eXtensible Business Reporting Language) for financial statement analysis. It illustrates how XBRL could change data workflow in order to decrease the costs of maintaining, reporting and analyzing financial data. The practical output is a software extension of MS Excel that can read and analyze online XBRL documents prepared as HTML with embedded XBRL. The theoretical part comprises an explanation of the technical background XBRL and important data workflows related to financial analysis and reporting financial data.

abstract: Data-driven applications are becoming increasingly complex with support for processing events and data streams in a loosely-coupled distributed environment, providing integrated access to heterogeneous data sources such as relational databases and XML documents. This dissertation explores the use of materialized views over structured heterogeneous data sources to support multiple query optimization in a distributed event stream processing framework that supports such applications involving various query expressions for detecting events, monitoring conditions, handling data streams, and querying data. Materialized views store the results of the computed view so that subsequent access to the view retrieves the materialized results, avoiding the cost of recomputing the entire view from base data sources. Using a service-based metadata repository that provides metadata level access to the various language components in the system, a heuristics-based algorithm detects the common subexpressions from the queries represented in a mixed multigraph model over relational and structured XML data sources. These common subexpressions can be relational, XML or a hybrid join over the heterogeneous data sources. This research examines the challenges in the definition and materialization of views when the heterogeneous data sources are retained in their native format, instead of converting the data to a common model. LINQ serves as the materialized view definition language for creating the view definitions. An algorithm is introduced that uses LINQ to create a data structure for the persistence of these hybrid views. Any changes to base data sources used to materialize views are captured and mapped to a delta structure. The deltas are then streamed within the framework for use in the incremental update of the materialized view. Algorithms are presented that use the magic sets query optimization approach to both efficiently materialize the views and to propagate the relevant changes to the views for incremental maintenance. Using representative scenarios over structured heterogeneous data sources, an evaluation of the framework demonstrates an improvement in performance. Thus, defining the LINQ-based materialized views over heterogeneous structured data sources using the detected common subexpressions and incrementally maintaining the views by using magic sets enhances the efficiency of the distributed event stream processing environment. / Dissertation/Thesis / Ph.D. Computer Science 2011

This thesis presents strategies to improve the query evaluation performance over huge volumes of relational-like data that is stored in the memory space of managed applications. Storing and processing application data in the memory space of managed applications is motivated by the convergence of two recent trends in data management. First, dropping DRAM prices have led to memory capacities that allow the entire working set of an application to fit into main memory and to the emergence of in-memory database systems (IMDBs). Second, language-integrated query transparently integrates query processing syntax into programming languages and, therefore, allows complex queries to be composed in the application. IMDBs typically serve as data stores to applications written in an object-oriented language running on a managed runtime. In this thesis, we propose a deeper integration of the two by storing all application data in the memory space of the application and using language-integrated query, combined with query compilation techniques, to provide fast query processing. As a starting point, we look into storing data as runtime-managed objects in collection types provided by the programming language. Queries are formulated using language-integrated query and dynamically compiled to specialized functions that produce the result of the query in a more efficient way by leveraging query compilation techniques similar to those used in modern database systems. We show that the generated query functions significantly improve query processing performance compared to the default execution model for language-integrated query. However, we also identify additional inefficiencies that can only be addressed by processing queries using low-level techniques which cannot be applied to runtime-managed objects. To address this, we introduce a staging phase in the generated code that makes query-relevant managed data accessible to low-level query code. Our experiments in .NET show an improvement in query evaluation performance of up to an order of magnitude over the default language-integrated query implementation. Motivated by additional inefficiencies caused by automatic garbage collection, we introduce a new collection type, the black-box collection. Black-box collections integrate the in-memory storage layer of a relational database system to store data and hide the internal storage layout from the application by employing existing object-relational mapping techniques (hence, the name black-box). Our experiments show that black-box collections provide better query performance than runtime-managed collections by allowing the generated query code to directly access the underlying relational in-memory data store using low-level techniques. Black-box collections also outperform a modern commercial database system. By removing huge volumes of collection data from the managed heap, black-box collections further improve the overall performance and response time of the application and improve the application’s scalability when facing huge volumes of collection data. To enable a deeper integration of the data store with the application, we introduce self-managed collections. Self-managed collections are a new type of collection for managed applications that, in contrast to black-box collections, store objects. As the data elements stored in the collection are objects, they are directly accessible from the application using references which allows for better integration of the data store with the application. Self-managed collections manually manage the memory of objects stored within them in a private heap that is excluded from garbage collection. We introduce a special collection syntax and a novel type-safe manual memory management system for this purpose. As was the case for black-box collections, self-managed collections improve query performance by utilizing a database-inspired data layout and allowing the use of low-level techniques. By also supporting references between collection objects, they outperform black-box collections.

The Master’s thesis deals with the proposal of database system for event management according to the requirements of the client, which is ANeT-Advanced Network Technology, Ltd. The first part of the thesis summarizes the theoretical bases of database systems and object-oriented programming focusing on .NET Framework. In the second part the current situation and the specific needs of the company are analyzed, and based on this analysis a solution proposal is created in the third part.

The Master’s thesis deals with design, realization and implementation of web application for ordering lunch. Theoretical basis for creating web applications, methods used for the proposal and technologies used in the realization and implementation are described in the first part. The second part of the thesis presents an analysis of the current state. The last part contains the actual design, realization and implementation of the web application for ordering lunches.

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Den här rapporten behandlar ett system som använder en databas som lagringsplats för loggar. En bra metod för att hämta ut dessa loggar saknades och databasdesignen behövde förbättras för sökningar i loggarna. En applikation för att hämta och söka i loggposter från databasen skapades. En undersökning om hur databasdesignen kunde förbättras genomfördes också. Båda delarna gjordes i ett projekt för att de hörde ihop. Applikationen skulle använda databasen. Då jag inte kunde göra vilka ändringar jag ville i databasen gjordes relativt begränsade ändringar i den. Större ändringar utreddes teoretiskt. Applikationen gjordes mot den existerande databasdesignen, med ett undantag: en vy lades till. Rapporten undersöker index och andra metoder att göra sökningar i en databas snabbare. En metod för att hämta data inom ett intervall i en databas utvecklades och den beskrivs i rapporten. Metoden söker efter all data som har värden på en kolumn som faller inom ett intervall och där databasen är ordnad, eller nästan ordnad, på den kolumnen. Metoden ger oexakta svar om databasen är nästan ordnad på den kolumnen. Den är snabbare än en motsvarande exakt sökning. / This report considers a system where a database is used as the back-end storage for logging. A suitable method for extracting information from the logs was missing and the database design needed an improvement for log searching. An application for extracting and filtering the logs was created. An evaluation of how the database could be improved was also performed. Both parts were done in one project since they were heavily connected. The application would use the database. Since I couldn’t make arbitrary changes to the database only relatively limited changes were made in practice. Larger changes were evaluated theoretically. The application was made against the existing database, with one exception: a view was added. The report handles indexes and other methods for speeding up database searches. A method for fetching data inside an interval in a database was developed and is described in the report. The method searches for all data where the value of a column is inside an interval and the database is ordered, or almost ordered, on that column. The method gives inexact answers if the database is almost ordered on that column. It is faster than a corresponding exact search.