Maximizing Data Warehouse ROI
The post in Beye Blogs gets to the core of Data Warehousing and explores what you need to enhance your ROI. Here are some extracts:
Having most granular (or detailed) transaction level data is core to broad-basing the Data Warehouse applications.
There reasons for using Data Warehouse as a single reference information source are:
1. Maintain consistency
2. If your production data needs an offline fix (like standardizing customer and product IDs), its better to do that data-fix in one place. If you have separate enterprise reporting and analysis platforms, you will need to do that data transformation at two places, instead of one.
3. Data Auditability: A single information reference point having detailed data will provide a good audit-trail of your summary transactions/analysis.
4. ETL synergy: If you have diverse systems, and you want to have some level of information integration, its better to do it at one place. Doing ETL for summary data warehouse and a detailed reporting database, will almost double your efforts.
5. Overall platform ease: You maintain only one information infrastructure (administration, scheduling, publishing, performance tuning…).
6. Ease of Change Management: Any change in your information requirements, or changes in your source systems will be managed and done at one place.
So then with all these benefits, why is there so much fuss about granular data in data-warehouse? Perhaps because it’s better? That’s how:
1. Brings forth the real issues with transactional data: In summary data warehouses, you can ignore some of the transaction level data issues and do some patch-work to ensure that aggregated data has a level of acceptable quality. Bringing in granular data, will need more incisive surgery on your data issues. This will extend the time of implementation.
2. ETL efforts go up: This is related to the first point. Your key plumbing task in DW will become larger and more complex.
3. Existing robust and stable reporting and querying platforms: Why to fix, which ain’t broken? etc…