Database design: one huge table or separate tables?

Question

Currently I am designing a database for use in our company. We are using SQL Server 2008. The database will hold data gathered from several customers. The goal of the databa

Answer 1

Datawarehouses are supposed to be big (the clue is in the name). Twenty million rows is about medium by warehousing standards, although six hundred million can be considered large.

The thing to bear in mind is that such large tables have a different physics, like black holes. So tuning them takes a different set of techniques. The other thing is, users of a datawarehouse must understand that they are dealing with huge amounts of data, and so they must not expect sub-second response (or indeed sub-minute) for every query.

Partitioning can be useful, especially if you have clear demarcations such as, as in your case, CUSTOMER. You have to be aware that partitioning can degrade the performance of queries which cut across the grain of the partitioning key. So it is not a silver bullet.