Ajilius supports different types of fact table:
- Periodic Snapshot
- Accumulating Snapshot
Aggregate fact tables may also be created over these basic types.
The type of fact table is defined at the time of table creation:
Transactional fact tables are the most common occurrence in a data warehouse. Events and measures around transactions are the foundation of business analytics.
Periodic Snapshot Fact
Rather than holding every transaction for one or more events, a periodic snapshot is a regular point-in-time summary.
Accumulating Snapshot Fact
Rather than measuring discrete events or periods, an accumulating snapshot can record the state of an event over time. This is because rather than being write-only, an accumulating snapshot is designed to be updated multiple times over its life.
From an Ajilius perspective, accumulating snapshots must carry a business key, to identify the fact row for updating.