§ Data Warehouse enhances end-user to wide variety of data.
§ It increases data consistency.
§ It increases productivity.
§ It decreases computer costs.
§ It is able to combine data from different sources in one place.
§ It provides infrastructure that could support changes to data and replication of the changed data back into operating systems.
§ It performs new types of analyses.
§ It Reduces cost to access historical data.
§ It Improves turnaround time for analysis and reporting.
§ Easy report creation.
§ Extracting, deleting, deleting data could be time consuming.
§ To provide training to end-user, who end up not using the data warehouse is time consuming and can be cost effective.
§ Security could develop into a serious issue, especially if the data warehouse is web accessible.
§ Data warehouses’ maintenance generates usually significant costs.
§ Data warehouses are often similar to operational systems and multiplying the same functionality generates superfluous costs that might have been easily omitted.
§ Limited flexibility of use and types of users
§ Difficult to accommodate changes in data types and ranges, data source schema, indexes and queries.
§ Compatibility with existing systems. Data owners lose control over their data, raising ownership (responsibility and accountability), security and privacy issues.
§ Adding new data sources takes time and associated high cost.
§ Major data schema transforms from each of the data sources to one schema in the data warehouse, which can represent more than 50% of the total data warehouse effort