Summary
In a DWH, fact tables present an additional challenge on top of merely capturing the latest values – they must also be able to capture and reconcile historical changes in a way that allows users to flexibly and cost-effectively query them to resolve business questions, because when it comes to operational analytics, analyzing changes, variations, and what didn’t happen can be just as valuable as the current state of truth.
Various types of fact tables exist to help an organization meet these demanding analytical needs, such as transactional, snapshot, and accumulating snapshot fact tables, among others. These fact tables must differentiate between the various kinds of measures they store (e.g., additive, semi-additive, and non-additive) because each is treated differently when updating or recording changes.
To help data teams construct and maintain these tables in Snowflake, this chapter dissected some of the toughest challenges in maintaining fact tables...