A data warehouse (DW) is a collection of corporate information and data derived from operational systems and external data sources. A data warehouse is designed to support business decisions by allowing data consolidation, analysis and reporting at different aggregate levels.
aggregate data mining and warehousing - … Data Warehousing and Data Mining Unit 1 and 2 - diz World. File Format: PDF/Adobe Acrobat Data Warehousing and Data Mining Unit 1 and 2 In data warehousing literature, each ofwhich is obtained by applying a distributive aggregate function
Aggregates are used in dimensional models of the data warehouse to produce dramatic positive effects on the time it takes to query large sets of data.At the simplest form an aggregate is a simple summary table that can be derived by performing a Group by SQL query.
Aggregating Data For The Oracle Warehouse. In order to create the illusion of fast calculation time, most data warehouses are loaded in batch mode after the online system has been shut down and all the common aggregate values are rolled up into summary tables.