Given the state of maturity of the data warehouse industry, you would think that all data warehouse platform decisions have already been made and that they've been made for good. You'd be wrong. Data warehouse platform/DBMS decisions are still being made due to:
- Non-producing data warehouse efforts that require zero-based planning
- Late data warehouse adopters
- Data warehouses hitting the scalability limitations of their initially chosen platforms
If you're in one of these shops, the following applies to you.
The data warehouse DBMS selection is critical and acts as a catalyst for all other technology decisions in a data warehouse environment. The technology needs to support both the immediate as well as future, unspecified and unknown requirements. Ideally the DBMS selection should be the first technology decision made for a data warehouse project and it should be:
- Scaleable -- In both performance capacity and incremental data volume growth. Make sure the proposed solution scales in a near-linear fashion and behaves consistently with growth in all of database size, number of concurrent users and complexity of queries. Understand additional hardware and software required for each of the incremental uses.
- Powerful -- Designed for complex decision support activity in a multi-user mixed workload environment. Check on the maturity of the optimizer for supporting every type of query with good performance and determine the best execution plan based on changing data demographics. Check on conditional parallelism and what the causes are of variations in the parallelism deployed. Check on dynamic and controllable prioritization of resources for queries.
- Manageable -- Through minimal support tasks requiring DBA/System Administrator intervention. It should provide a single point of control to simplify system administration. You should be able to create and implement new tables and indexes at will.
I'll have 6 more criteria in the next tip.
For more information, check out SearchCRM's Best Web Links on Data Warehousing.