tutorial-04

OLAP | Data Analysis with DB21 Data Analysis and OLAP Aggregate functions summarize large volumes of data. Online Analytical Processing (OLAP):. Interactive analysis of data.. Allows data to be summarized and viewed in di erent ways in an online fashion(with negligible delay). OLAP data is modeled multi-dimensionally. It can be modeled as dimension attributes and measure attributes:. Given a relation used for data analysis, we can identify some of its attributes asmeasure attributes, since they measure some value and can be aggregated upon(e.g., number of sales, inhabitants, passengers, etc.).. Someoftheotherattributesoftherelationareidenti ed asdimensionattributes,since they de ne the dimensions on which measure attributes and summaries ofmeasure attributes are viewed.c 2005 Jens Teubner, Andre Seifert, University of Konstanz 11.1 Cross Tabulation and its Relational Representation A cross tabulation, also referred to as a pivot table, is a table where. values of one of the dimension attributes form the row headers,. values of another attribute form the column headers, and. valuesinindividual cellsare(aggregates of)thevaluesofthedimensionattributesthat specify the cell. The table below is an example of a cross tab:SexMale Female TotalAustralia 9;913;658 9;999;486 19;913;144Denmark 2;676;377 2;737;015 5;413;392Germany 40;413;132 42;011;477 82;424;609Netherlands 8;079;392 8;238;807 16;318;199United States 143;957;558 149;070;013 293 ...