When you’re using a data warehouse, some actions get repeated over and over. We will take a look at four common algorithms used to deal with these situations. Most DWH (data warehouse) systems today are on a RDBMS (relational database management system) platform. These databases (Oracle, DB2, or Microsoft SQL Server) are widely used, easy to work with, and mature – a very important thing to bear in mind when choosing a platform.
When designing your dimensional model, it is worthwhile to watch out for mistakes that commonly occur during the process. Specifically, they can occur in the relationships between tables, both in fact-to-dimension and dimension-to-dimension relationships. In this post, we’re going to take a closer look at five common modeling mistakes and what you can do about them. As you start a BI-related project, bulletproof dimensional design is hugely important. What makes a design bulletproof is the early mitigation of common design mistakes.
When we start a data warehousing project, the first thing we do is define the dimensional tables. Dimensional tables are the interesting bits, the framework around which we build our measurements. They come in many shapes and sizes. In this article, we are going to take a closer look at each type of dimensional table. Dimensional tables provide context to the business processes we wish to measure. They tell us all we need to know about an event.
The process of defining your data warehousing system (DWH) has started. You’ve outlined the relevant dimension tables, which tie to the business requirements. These tables define what we weigh, observe and scale. Now we need to define how we measure. Fact tables are where we store these measurements. They hold business data that can be aggregated across dimension combinations. But the fact is that fact tables are not so easily described – they have flavors of their own.