The Role and Value of Data Warehousing and Analytics as Aspects of Business Intelligence

The Role and Value of Data Warehousing and Analytics as Aspects of Business Intelligence

Introduction

A data warehouse is a centralized, large-sized repository of databases and data files that allows users to access data, to perform data query functions, or to conduct data analyses. Most data warehouses utilize advanced network technologies and frameworks (such as the Internet and the World Wide Web) to provide flexible access of databases and files. Inmon and Kelly (1993) noted that data warehouses should provide a subject-oriented, integrated, time-variant, and nonvolatile collection of data in support of management's decision-making process. The major goal of a data warehouse is to facilitate data archiving, data searching, and data sharing for multiple users. A centralized data warehouse can increase data consistency and decrease the cost of data maintenance.

The implementation of data warehouses is important for many GIS projects and applications. Many federal and local governments in the United States have established various geospatial data warehouses for land use data, transportation data, satellite imagery, and other municipal GIS data sets. The Internet and the Web are now the storage devices or media used for the archiving and delivery of GIS data layers and remotely sensed imagery. The Web-based geospatial data warehouses can allow users to catalog, index, and search these data sets in what are now recognized as digital libraries.

Metadata for GIS Data Warehouses

A metadata framework is essential to the operation of data warehouses, and it is pivotal for the functions of data acquisition/collection, data transformation, and data access. Most Web-based geospatial data warehouses are populated by two types of data: GIS mapping layers and remotely sensed imagery.

For general GIS mapping layers, the ISO 19115 Metadata Standard can offer a conceptual framework and an implementation approach. The ISO 19115 Metadata Standard, created by the International Organization for Standardization (ISO) Technical Committee (TC) 211, is the major international geospatial metadata standard. This metadata standard was based partially on the 1994 U.S. Federal Geographic Data Committee's (FGDC) Content Standard for Digital Geospatial Metadata (CSDGM). A major advantage of the ISO 19115 and CSDGM Metadata Standards is their flexibility in allowing the creation of extensions and profiles for various applications.

For remotely sensed imagery, the remote-sensing community has defined metadata extensions for remote-sensing research and applications based on the CSDGM. These were formally approved by the FGDC in 2002 as the Content Standard for Digital Geospatial Metadata: Extensions for Remote Sensing Metadata.

Web-Based Geospatial Data Warehouse Functions

In general, a Web-based geospatial data warehouse should provide an easy-to-use mechanism for data users to access or download GIS data and remotely sensed images. Users can combine their own local GIS data sets with data from Web-based warehouses. Four general system functions must be provided by Web-based geospatial data warehouses: a metadata search function, a metadata display function, a data preview function, and a data download function.

The metadata search function should be created to allow users to enter keywords or provide inputs for searching the metadata ...