A Comprehensive Method for Data Warehouse Design

I nformation assets are immensely valuable to any enterprise, and because of this, these assets must be properly stored and readily accessible when they are needed. However, the availability of too much data makes the extraction of the most important information difficult, if not impossible. View results from any Google search, and you'll see that the data = information equation is not always correct-that is, too much data is simply too much.

2000

Proceedings of the 9th ACM international workshop on Data warehousing and OLAP - DOLAP '06, 2006

Multidimensional modeling requires specialized design techniques. Though a lot has been written about how a data warehouse should be designed, there is no consensus on a design method yet. This paper follows from a wide discussion that took place in Dagstuhl, during the Perspectives Workshop "Data Warehousing at the Crossroads", and is aimed at outlining some open issues in modeling and design of data warehouses. More precisely, issues regarding conceptual models, logical models, methods for design, interoperability, and design for new architectures and applications are considered.

Data Warehouse Systems, 2014

A data warehouse is an integrated and timevarying collection of data derived from operational data and primarily used in strategic decision making by means of online analytical processing (OLAP) techniques. Although it is generally agreed that warehouse design is a non-trivial problem and that multidimensional data models and star or snowflake schemata are relevant in this context, hardly any methods exist to date for deriving such a schema from an operational database. In this paper, we fill this gap by showing how to systematically derive a conceptual warehouse schema that is even in generalized multidimensional normal form.

2003

Data Warehouse-(DW) logical design often start with a conceptual schema and then generates relational structures. Applying this approach implies to cope with two main aspects: (i) -mapping the conceptual model structures to the logical model ones, and (ii) -taking into account implementation issues, which are not considered in the conceptual schema. This paper addresses this second aspect and presents a formalism that allows the DW designer to specify design guidelines which express design strategies related with implementation requirements. Through these guidelines the designer states high level manners to cope with different design problems, for example: managing complex and big dimensions, dimension versioning, different user profiles accessing to different attributes, high summarized data, horizontal partitions of historical data, generic dimensionality and non-additive measures. This work is part of a DW logical design environment, where the design guidelines are specified through a graphical editor and then automatically processed in order to build the logical schema.

International Geology Review, 2000

The Phanerozoic geodynamic evolution of Europe is reviewed for the purpose of identifying its bearing on the petrogenesis of the Cenozoic European Volcanic Province. Several events capable of modifying the chemistry and mineralogy of the mantle, such as subduction of oceanic crust, continent-continent collision, and ocean formation are emphasized. The area now occupied by the Mediterranean Sea and, in general, all of Europe, underwent a complex geodynamic evolution, involving large relative crustal movements. The Paleozoic to Recent evolution of the circum-Mediterranean Sea area can be summarized as follows: (1) extension during the Precambrian (presence of ~3000 to 4000 km wide oceanic crust between Laurussia (consisting of the Laurentian and Baltica-Fennoscandian cratons) and Gondwana (South America, Africa, Australia, India, and Antarctica); (2) collisional movements with the formation of "Andean-type" margins during the Late Precambrian to Middle Paleozoic, followed by "Himalayan-type" margins during the Carboniferous (Hercynian orogeny sensu stricto); (3) change of plate movements and development of tensional (transtensive) stresses at the end of the Paleozoic, as indicated by the formation of the North Atlantic-Tethys rift system, with the Cretaceous formation of the Ligurian-Piedmontese and the Mesogean Ocean; (4) the Alpine orogeny, with a two-stage compressive cycle-(a) Eoalpine (Paleogene closure of the Ligurian-Piedmontese Ocean; formation of the Betic Cordillera, western-northern Alps, and Carpatho-Balkan Arc), with Europe-verging thrusts; and (b) Neoalpine (Neogene-Pleistocene formation of the Apennine, Maghrebide, Dinaride, and Hellenide chains, plus the backthrusted southern Alps, all with African vergence; opening of two diachronous backarc basins-the Ligurian-Provençal Basin and the Tyrrhenian Sea-in the western Mediterranean). Hercynian-age modifications (the most important of which are subduction-related) led to almost unique isotopic ratios, such as low 143 Nd/ 144 Nd, 206 Pb/ 204 Pb, 3 He/ 4 He, and slightly radiogenic 87 Sr/ 86 Sr ratios.

2015

In their natural environment wild species have little need for supplementary feeding as their free ranging habits enable them to pursue more nutritious grazing and therefore satisfy their requirements. With the advent of game forming wild animals have been confined to limited areas and this has necessitated some form of supplementary feeding. In the case of zoo animals their total feed requirements have to be met.