Data warehouse is a collection of huge database which is subject oriented, integrated, time-variant and non volatile. As it is a set of huge database, fast data access is the major performance parameter of any data warehouse. Generally the information retrieved from Data Warehouse is summarized or aggregated as it is required for some decision making process of organization. To retrieve such a ...

Materialized view selection is one of the most crucial techniques to design data warehouse in an optimal manner. Selecting views to materialize for the purpose of supporting the decision making efficiently is one of the most significant decisions in designing Data Warehouse. Selecting a set of derived views to materialize which minimizes the sum of total query response time and maintenance of t...

A Data Warehouse (DW) is a repository of information retrieved from multiple, possibly heterogeneous, autonomous, distributed databases and other information sources for the purpose of complex querying, analysis and decision support. Data in the DW are selectively collected from the sources, processed in order to resolve inconsistencies, and integrated in advance (at design time) before data lo...

The wind’s effectiveness was compared in different points of a watershed using a quantity called The Wind Shelter Index.The wind’s effectiveness was compared in different points of a watershed using a quantity called The Wind Shelter Index. It is necessary to choose a distance called the effective distance in the process of this index determination. The criterion already used for this purpose w...

View Materialization is an effective method to increase query efficiency in a data warehouse. However, one encounters the problem of space insufficiency if all possible views are materialized in advance. Reducing query time by means of selecting a proper set of materialized views with a lower cost is crucial for efficient data warehousing. In addition, the costs of data warehouse creation, quer...

PT Warung Islami Bogor needs a warehouse to store goods that come from suppliers. Currently, the selection of warehouses is still done manually and subjective. It feared this will lead inaccuracies in renting warehouse. So an application needed assist companies choosing The fuzzy C-Means method can be used classify data based on characteristics each group. After obtaining next group make rating...

In many applications one has to fetch and assemble pieces of information coming from more than one source for building a semantic warehouse offering more advanced query capabilities. In this paper we describe the corresponding requirements and challenges, and we focus on the aspects of quality and value of the warehouse. For this reason we introduce various metrics (or measures) for quantifying...

A data warehouse stores a large volume of data extracted from multiple sources. A set of materialized views is defined over the base tables in order to optimize OLAP (On-Line Analytical Processing) query response time. The selection of materialized views may be static or dynamic. The dynamic selection is continually controlled by a system that calibrates the set of views. The static selection i...

Careful selection of aggregate views and some of their most used indexes to materialize in a data warehouse reduces the warehouse query response time as well as warehouse maintenance cost under some storage space constraint. Data Warehouses collect and store large amounts of integrated enterprise data from a number of independent data sources over a long period of time. Warehouse data are used ...