To appreciate the wealth of information a data warehouse has to offer, you need to understand how to communicate with it. Information is typically accessed using an SQL query. The statement responsible for querying the many tables and returning the requested results in a data warehouse environment is the SELECT statement. It is an indispensable piece of the data retrieval process. This paper lo...

With the development of petroleum informatization and increase of drilling data, data storage, analysis and integration is attached to the key planning process. Therefore, a solution is needed which combines the data integration, management, analysis and decision support. Data warehouse is one of the hot topics in computer technology application, which has solved the problem of data using after...

Most work on data warehousing addresses aspects related to the internal operation of a data warehouse server, such as selection of views to materialise, maintenance of aggregate views and performance of OLAP queries. Issues related to data warehouse maintenance, i.e. how changes to autonomous sources should be detected and propagated to a warehouse, have been addressed in a fragmented manner. A...

The data warehousing is becoming increasingly important in terms of strategic decision making through their capacity to integrate heterogeneous data from multiple information sources in a common storage space, for querying and analysis. So it can evolve into a multi-tier structure where parts of the organization take information from the main data warehouse into their own systems. These may inc...

First step towards understanding any agricultural system is the comprehension of relationships between the system and numerous physical, chemical and biological factors influencing it. Any decision regarding such systems requires analytical exploration of the involved data. The exploration task is to be supported by an efficient data storage and retrieval mechanism. In this paper we have presen...

Effective analysis of genome sequences and associated functional data requires access to many different kinds of biological information. A data warehouse [14,16] plays an important role for storage and analysis for genome sequence and functional data. A data warehouse stores lots of materialized views to provide an efficient decision-support or OLAP queries. The view-selection problem addresses...

Data warehouse views typically store large aggregate tables based on a subset of dimension attributes of the main data warehouse fact table. Aggregate views can be stored as 2n subviews of a data cube with n attributes. Methods have been proposed for selecting only some of the data cube views to materialize in order to speed up query response time, accommodate storage space constraint and reduc...

This paper brings together two research areas, i.e. “Data Warehouses” and “Temporal Databases”, involving representation of time. Looking at temporal aspects within a data warehouse, more similarities than differences between temporal databases and data warehouses have been found. The first closeness between these areas consists in the possibility of a data warehouse redefinition in terms of a ...