Marcus Costa Sampaio

An Introductory Overview and Survey of Business-Driven IT Management

Business-driven IT management (BDIM) is a new, evolutionary and comprehensive IT management approach that aims to improve IT infrastructure, service quality and business results at the same time. To that end, it needs to model and numerically estimate IT-business linkage. BDIM concepts are finding ways into ITIL-based management processes as well as into new IT infrastructure product offerings such as autonomic computing in order to add increased value to the business. In the hope of contributing to define and characterize this new approach, this paper presents an introductory overview of BDIM, discusses its main concepts, illustrates gains over conventional IT management approaches and offers a survey of some recent work on the topic in the literature.

SLA design from a business perspective

A method is proposed whereby values for Service Level Objectives (SLOs) of an SLA can be chosen to reduce the sum IT infrastructure cost plus business financial loss. Business considerations are brought into the model by including the business losses sustained when IT components fail or performance is degraded. To this end, an impact model is fully developed in the paper. A numerical example consisting of an e-commerce business process using an IT service dependent on three infrastructure tiers (web tier, application tier, database tier) is used to show that the resulting choice of SLOs can be vastly superior to ad hoc design. A further conclusion is that infrastructure design and the resulting SLOs can be quite dependent on the “importance” of the business processes (BPs) being serviced: higher-revenue BPs deserve better infrastructure and the method presented shows exactly how much better the infrastructure should be.

Towards a logical multidimensional model for spatial data warehousing and OLAP

Decision support systems (DSS) may be enhanced qualitatively if they are able to also deal with spatial dimensions and measures. Regardless the evident importance of using data warehousing and OLAP in DSS, the incorporation of spatial dimensions and measures enables to locate more efficiently tendencies in a given application domain, by using dynamic maps with zooming, panning, aggregation and other spatial functionalities. Therefore, it is necessary to converge two relatively consolidated technologies: Data Warehousing and Geographical Information Systems. This integration gives raise to a new research area called Spatial Data Warehousing (SDW), which introduces new research challenges. This paper proposes a novel logical multidimensional model suitable for SDW, which is implemented on the top of an object-relational database system with support for spatial data. Moreover, the paper addresses query optimization techniques to enhance performance and it describes a prototype, which has been built to validate the proposed ideas.

Optimal Design of E-Commerce Site Infrastructure from a Business Perspective

A methodology for designing data center infrastructure for E-commerce sites is developed. It differs from existing methodologies in that it evaluates and compares alternative designs from a business perspective, that is, by evaluating the business impact (financial loss) imposed by imperfect infrastructure. The methodology provides the optimal infrastructure that minimizes the sum of provisioning costs and business losses incurred during failures and performance degradations. A full numerical example design is provided and results are analyzed. The use of the method for dynamically provisioning an adaptive infrastructure is briefly discussed.

Efficient materialization and use of views in data warehouses

Given the complexity of many queries over a Data Warehouse (DW), it is interesting to precompute and store in the DW the answer sets of some demanding operations, so called materialized views. In this paper, we present an algorithm, including its experimental evaluation, which allows the materialization of several views simultaneously without losing sight of processing costs for queries using these materialized views.

PhotoGeo: A Self-Organizing System for Personal Photo Collections

Nowadays the photo-capturing devices are no longer limited to digital cameras but include mobile phones, PDAs and others. This is leading to a new problem: a very large number of digital photos captured and chaotically stored in multiple locations without being annotated. This paper presents a new system, called PhotoGeo, for self-organization of georeferenced photos. The proposed system uses metadata and external sources to organize the photos. These external sources include a map-based social network and userpsilas calendar. Furthermore, spatial clustering and temporal segmentation techniques are used to join the photos into clusters with similar features.

Incremental updates on mobile datawarehousing using optimized hierarchical views and new aggregation operators

The use of mobile applications is increasing rapidly. Particularly, mobile applications for decision support systems, such as mobile data warehouses, are very attractive. However, mobile application imposes new requirements such as disconnection from the data sources. These requirements force the use of incremental update algorithms in order to update the mobile hosts. We extend the idea of incremental update algorithms with an optimized hierarchy of views which enables improving performance on mobile data warehouses. Moreover, we prove that other aggregate functions apart from the standard ones, in particular, standard deviation, variance, and ratiotoreport, are suitable for being used in incremental update algorithms.

Cooperative transactions: a data-driven approach

We present a new cooperative transaction model. The model has been developed using a data-driven approach, where we have not considered constraints specific to one application class, but only data-specific constraints. This approach is more general than the application-driven approach adopted in other cooperative transaction models. The notion of a set of complementary objects is intrinsic here. Two objects belong to a set of complementary objects if they are connected by dependency relations, directly or transitively. A set of users, represented by cooperative transactions within a cooperative unit, shares the consistency preservation of a set of complementary objects (global consistency). Responsibilities are separated: the set of complementary objects is divided into disjointed subsets, each being manipulated by at most one user. Global consistency is achieved by selective cooperation between users in order to take into account the dependency relations between the respective objects that they manipulate. The model enforces two grades of selective cooperation. In weak cooperation, a user makes his final effects visible to another (one-way cooperation). In strong cooperation users make their intermediate effects symmetrically visible (two-way cooperation). Global consistency is ensured when there are concurrent transactions external to the cooperative unit, and in case of failure.

Information Retrieval from database queries

Databases and documents are usually confined into separated environments inside organizations, controlled by Database Management Systems (DBMS) and Information Retrieval Systems (IRS), respectively. However, both DBMS and IRS frequently store data about the same entities, in this way presenting opportunities for integration. We propose a framework for DBMS-IRS integration that uses top ranked terms from a database query result as keywords for an IRS search, thus retrieving documents strongly related to the query. Indeed, the framework uses the ranked terms to “expand” an initial keyword search provided by the user. Moreover, our term ranking method measures the utility of a term through its dispersion along a query result, exploiting the fact that the query provides exact answers to the information need. Our experiments have confirmed the superiority of the approach to DBMS-IRS integration, as well as the effectiveness of our term ranking method.

WebObjects: A New Approach for Querying the Web

Although there is a great effort on the development of Web search engines, search results are still poor in terms of precision and recall. This paper presents WebObjects, a new approach for querying the Web. WebObjects consists of a framework which enables Web searching using OQL queries according to the ODMG 3.0 standard. By using this query language we obtain high expressiveness on Web searching and it maximizes precision. Moreover, WebObjects validates the result set in order to avoid broken links. Finally, experimental results using the framework are reported.